3
NLM CIT. ID: 98195442
TITLE: Binocular rivalry and motion perception.
AUTHORS: Blake R; Yu K; Lokey M; Norman H
AUTHOR AFFILIATION:
Vanderbilt University, Department of Psychology, Nashville TN 37240,
USA. [EMAIL PROTECTED]
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY07760/EY/NEI
P30-EY08126/EY/NEI
ABSTRACT:
In a series of experiments psychophysical techniques were used to
study the relation between binocular rivalry and motion perception.
An initial series of experiments confirmed that motion enhances the
predominance of an eye during rivalry, although the direction of
motion does not matter. The presence of an annulus of motion
immediately surrounding one eye's rival target greatly enhances
dominance of that target, but the influence of the annulus
progressively decreases as the separation between disk and annulus
increased. Opponent directions of motion in disk and annulus yield
greater dominance than when dots in the disk and annulus moved in
identical directions. In a second experiment that two eyes were
adapted to orthogonal directions of motion, generating strong,
distinctively different monocular motion aftereffects (MAEs). Even
though the two eyes view physically identical random-motion displays
following differential adaptation, binocular rivalry of the
discrepant MAEs can occur. Finally, using a stimulus replacement
technique to measure detectability of translational and rotational
motion, it was found that both types of motion were readily detected
during periods of dominance but went undetected during periods of
suppression. Taken together, these results bear on the process
responsible for rivalry and its neural locus relative to the analysis
of different types of motion.
MAIN MESH HEADINGS:
Motion Perception/*physiology
Vision, Binocular/*physiology
ADDITIONAL MESH HEADINGS:
Adaptation, Ocular/physiology
Animal
Human
Laterality/physiology
Models, Neurological
Support, U.S. Gov't, Non-P.H.S.
Support, U.S. Gov't, P.H.S.
Vision, Monocular/physiology
NLM PUBMED CIT. ID:
9526082
SOURCE: J Cogn Neurosci 1998 Jan;10(1):46-60
4
NLM CIT. ID: 98112180
TITLE: "... On the basis of velocity clues alone": some perceptual themes
1946- 1996.
AUTHORS: Mollon JD
AUTHOR AFFILIATION:
Department of Experimental Psychology, University of Cambridge.
[EMAIL PROTECTED]
PUBLICATION TYPES:
HISTORICAL ARTICLE
LECTURES
LANGUAGES:
Eng
ABSTRACT:
Three factors that have transformed perceptual research in the last
fifty years are the digital computer, single-unit electrophysiology,
and molecular biology. Amongst the developments in which members of
the Experimental Psychology Society have been central are: the
recognition of the role of optic flow in spatial vision; the
demonstration that our perceptual systems contain parallel pathways
extracting different information from the sensory array; the
identification of specific detectors that can be selectively adapted
in psychophysical experiments; and the transfer of the concepts of
fourier analysis from audition to vision. The history of Opponent
Process Theory offers an example where experimental psychologists
have been misled by too simple an interpretation of physiological
recordings.
MAIN MESH HEADINGS:
Psychology, Experimental/*trends
Psychophysics/*trends
Visual Perception/*physiology
ADDITIONAL MESH HEADINGS:
Animal
Computers
History of Medicine, 20th Cent.
Human
Psychology, Experimental/history
Support, Non-U.S. Gov't
NLM PUBMED CIT. ID:
9450381
SOURCE: Q J Exp Psychol A 1997 Nov;50(4):859-78
NLM CIT. ID: 97301196
TITLE: Influence of luminance flicker and purity on heterochromatic
brightness matching and hue discrimination: a postreceptoral opponent
process.
AUTHORS: Kurtenbach A; Ruttiger L; Kaiser PK; Zrenner E
AUTHOR AFFILIATION:
Department of Pathophysiology of Vision and Neuro-ophthalmology,
University Eye Hospital, Tubingen, Germany.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
We have studied psychophysically the characteristics of the
postreceptoral stage of visual processing, using heterochromatic
brightness matching (HBM) between 540 and 600 nm, and hue
discrimination between 565 and 585 nm, under differing luminance
flicker (0-30 Hz) and excitation purity (1.0-0.1) conditions. The HBM
curves exhibit deeper minima around 575 nm with decreasing purity.
The minimum is generally most pronounced with a 3 Hz flicker and
least pronounced with a 30 Hz flicker. Hue discrimination ability is
relatively insensitive to flicker and deteriorates at the lower
purities. The HBM results for low purities can be explained by the
upper envelope of activities in PC- and MC-pathways.
MAIN MESH HEADINGS:
Color Perception/*physiology
ADDITIONAL MESH HEADINGS:
Adult
Discrimination (Psychology)
Human
Light
Male
Psychophysics
Spectrophotometry
Support, Non-U.S. Gov't
Time Factors
Vision, Monocular/physiology
Visual Pathways
NLM PUBMED CIT. ID:
9156216
SOURCE: Vision Res 1997 Mar;37(6):721-8
NLM CIT. ID: 97215287
TITLE: Colour adaptation modifies the long-wave versus middle-wave cone
weights and temporal phases in human luminance (but not red-green)
mechanism.
AUTHORS: Stromeyer CF 3rd; Chaparro A; Tolias AS; Kronauer RE
AUTHOR AFFILIATION:
Division of Applied Sciences, Harvard University, Cambridge, MA 02138,
USA. [EMAIL PROTECTED]
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY11246/EY/NEI
EY01808/EY/NEI
ABSTRACT:
1. The human luminance (LUM) mechanism detects rapid flicker and
motion, responding to a linear sum of contrast signals, L' and M',
from the long-wave (L) and middle-wave (M) cones. The red-green
mechanism detects hue variations, responding to a linear difference
of L' and M' contrast signals. 2. The two detection mechanisms were
isolated to assess how chromatic adaptation affects summation of L'
and M' signals in each mechanism. On coloured background (from blue
to red), we measured, as a function of temporal frequency, both the
relative temporal phase of the L' and M' signals producing optimal
summation and the relative L' and M' contrast weights of the signals
(at the optimal phase for summation). 3. Within the red-green
mechanism at 6 Hz, the phase shift between the L' and M' signals was
negligible on each coloured field, and the L' and M' contrast weights
were equal and of opposite sign. 4. Relative phase shifts between the
L' and M' signals in the LUM mechanism were markedly affected by
adapting field colour. For stimuli of 1 cycle deg-1 and 9 Hz, the
temporal phase shift was zero on a green-yellow field (approximately
570 nm). On an orange field, the L' signal lagged M' by as much as 70
deg phase while on a green field M' lagged L' by as much as 70 deg.
The asymmetric phase shift about yellow adaptation reveals a
spectrally opponent process which controls the phase shift. The phase
shift occurs at an early site, for colour adaptation of the other eye
had no effect, and the phase shift measured monocularly was identical
for flicker and motion, thus occurring before the motion signal is
extracted (this requires an extra delay). 5. The L' versus M' phase
shift in the LUM mechanism was generally greatest at intermediate
temporal frequencies (4-12 Hz) and was small at high frequencies
(20-25 Hz). The phase shift was greatest at low spatial frequencies
and strongly reduced at high spatial frequencies (5 cycle deg-1),
indicating that the receptive field surround of neurones is important
for the phase shift. 6. These temporal phase shifts were confirmed by
measuring motion contrast thresholds for drifting L cone and M cone
gratings summed in different spatial phases. Owing to the large phase
shifts on green or orange fields, the L and M components were
detected about equally well by the LUM mechanism (at 1 cycle deg-1
and 9 Hz) when summed spatially in phase or in antiphase. Antiphase
summation is typically thought to produce an equiluminant red-green
grating. 7. At low spatial frequency, the relative L' and M' contrast
weights in the LUM mechanism (assessed at the optimal phase for
summation) changed strongly with field colour and temporal frequency.
8. The phase shifts and changing contrast weights were modelled with
phasic retinal ganglion cells, with chromatic adaptation strongly
modifying the receptive field surround. The cells summate L' and M'
in their centre, while the surround L' and M' signals are both
antagonistic to the centre for approximately 570 nm yellow
adaptation. Green or orange adaptation is assumed to modify the L and
M surround inputs, causing them to be opponent with respect to each
other, but with reversed polarity on the green versus orange field
(to explain the chromatic reversal of the phase shift). Large changes
in the relative L' and M' weights on green versus orange fields
indicate the clear presence of the spectrally opponent surround even
at 20 Hz. The spectrally opponent surround appears sluggish, with a
long delay (approximately 20 ms) relative to the centre.
MAIN MESH HEADINGS:
Color Perception/*physiology
Retinal Ganglion Cells/*physiology
ADDITIONAL MESH HEADINGS:
Adult
Human
Male
Middle Age
Motion
Photic Stimulation
Support, Non-U.S. Gov't
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
9061652
SOURCE: J Physiol (Lond) 1997 Feb 15;499 ( Pt 1):227-54
10
NLM CIT. ID: 97131340
TITLE: Mechanisms specialized for the perception of image geometry.
AUTHORS: Heeley DW; Buchanan-Smith HM
AUTHOR AFFILIATION:
School of Psychology, University of St. Andrews, U.K.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
Angle discrimination thresholds were obtained for V-shaped targets
with a base angle of 90 deg at four different pattern orientations
(0, 45, 90 and 135 deg). A comparison of these thresholds with the
orientation discrimination thresholds for the single lines from which
the patterns had been constructed, revealed that angle acuity cannot
be predicted from component acuity. Angle acuity is finer than the
corresponding orientation acuity in all cases and does not exhibit
the pronounced oblique effect that is found for orientation
discrimination. Other experiments showed that acuity for pattern
angle depends critically on base angle, with minima close to 0, 90
and 180 deg. The shape and amplitude of this function are independent
of pattern orientation. It was found that the angle acuity was
unaffected by excluding a large portion of the target in the region
of the vertex, and that the pattern of dependence of acuity on angle
changed radically when the target was reduced ultimately to three
blobs that defined the cardinal points of the stimulus. The data
suggest that when the target comprises line segments, angle
discrimination is not limited by noise that arises at early levels of
processing and that angle perception is mediated by mechanisms that
are specialized for the perception of image geometry. An opponent
process model, that is based on the combined outputs of just two
types of filter, is proposed as the basis for the perception of image
geometry. This type of system is appropriate for computing one of the
differential invariants in an optic flow field.
MAIN MESH HEADINGS:
*Models, Psychological
*Space Perception
ADDITIONAL MESH HEADINGS:
Discrimination (Psychology)
Human
Psychophysics
Sensory Thresholds
Support, Non-U.S. Gov't
Visual Acuity
NLM PUBMED CIT. ID:
8976992
SOURCE: Vision Res 1996 Nov;36(22):3607-27
NLM CIT. ID: 96292773
TITLE: Second-order excitation mediated by a backward conditioned inhibitor.
AUTHORS: Barnet RC; Miller RR
AUTHOR AFFILIATION:
Department of Psychology, Dalhousie University, Halifax, Nova Scotia,
Canada.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
33881
ABSTRACT:
Conditioned suppression studies with rats explored the informational
content of a backward conditioned inhibitor. Pairings of an
unconditioned stimulus (US) and Stimulus 1 (US-->S1) established S1
as an inhibitor in Experiment 1. Pairing the inhibitor S1 with a
novel S2 (S2-->S1) promoted excitatory second-order conditioning
(SOC) to S2, which suggested S1 was well associated with the US.
Degrading presumed S1-US associations in Experiment 2 by S1-
(extinction) treatment eliminated S2's excitation while preserving
S1's inhibition. Experiments 3 and 4 converged in showing that S2 was
not an excitor when Pavlovian conditioned inhibition (CI) was the
inhibitory treatment prior to the SOC phase, but instead acted as a
second-order inhibitor. Results are discussed in relation to the
temporal coding hypothesis, the SOP ("sometimes opponent process")
and Rescorla-Wagner models of conditioning, and the associative
structure of SOC. Also, the data suggest that backward inhibition is
special and that not all forms of CI are equal.
MAIN MESH HEADINGS:
*Association Learning
*Conditioning, Classical
*Inhibition (Psychology)
ADDITIONAL MESH HEADINGS:
Animal
Extinction (Psychology)
Female
Male
Rats
Rats, Sprague-Dawley
Recall
Support, Non-U.S. Gov't
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
8691159
SOURCE: J Exp Psychol Anim Behav Process 1996 Jul;22(3):279-96
NLM CIT. ID: 96338883
TITLE: EEG power spectral densities during and after cycle ergometer
exercise.
AUTHORS: Kubitz KA; Mott AA
AUTHOR AFFILIATION:
Department of Kinesiology at Kansas State University.
[EMAIL PROTECTED]
PUBLICATION TYPES:
CLINICAL TRIAL
CONTROLLED CLINICAL TRIAL
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
This study examined the effects of aerobic exercise on spontaneous
electroencephalographic (EEG) activity. Participants (N = 34) were
asked to (a) sit quietly for a 10-min adaptation period, (b) either
exercise on a cycle ergometer (n = 18) or watch a videotape (n = 16)
for 15 min, and (c) sit quietly for a 10-min recovery period. EEGs
were collected during the last 2 min of the adaptation period, the
last 2 min of each 5-min stage of the exercise/videotape period, and
the last 2 min of the recovery period. EEG power densities were
combined across the alpha and beta frequency bands. The results
indicated that brain activation increased (i.e., alpha activity
decreased and beta activity increased) during the exercise condition
and returned to baseline following exercise. This did not occur in
the nonexercise condition. Thus, the results were consistent with the
opponent-process theory (Solomon, 1980) in that brain activation
increased during exercise.
MAIN MESH HEADINGS:
*Adaptation, Physiological
Brain/*physiology
*Electroencephalography
Exercise/*physiology
ADDITIONAL MESH HEADINGS:
Adult
Alpha Rhythm
Beta Rhythm
Female
Human
Male
Support, Non-U.S. Gov't
NLM PUBMED CIT. ID:
8735998
SOURCE: Res Q Exerc Sport 1996 Mar;67(1):91-6
16
NLM CIT. ID: 96402789
TITLE: Brightness perception, illusory contours, and corticogeniculate
feedback.
AUTHORS: Gove A; Grossberg S; Mingolla E
AUTHOR AFFILIATION:
MIT Lincoln Laboratory, Lexington, MA, USA.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
A neural network model is developed to explain how visual
thalamocortical interactions give rise to boundary percepts such as
illusory contours and surface percepts such as filled-in
brightnesses. Top-down feedback interactions are needed in addition
to bottom-up feed- forward interactions to simulate these data. One
feedback loop is modeled between lateral geniculate nucleus (LGN) and
cortical area V1, and another within cortical areas V1 and V2. The
first feedback loop realizes a matching process which enhances LGN
cell activities that are consistent with those of active cortical
cells, and suppresses LGN activities that are not. This
corticogeniculate feedback, being endstopped and oriented, also
enhances LGN ON cell activations at the ends of thin dark lines,
thereby leading to enhanced cortical brightness percepts when the
lines group into closed illusory contours. The second feedback loop
generates boundary representations, including illusory contours, that
coherently bind distributed cortical features together. Brightness
percepts form within the surface representations through a diffusive
filling-in process that is contained by resistive gating signals from
the boundary representations. The model is used to simulate illusory
contours and surface brightness induced by Ehrenstein disks, Kanizsa
squares, Glass patterns, and cafe wall patterns in single contrast,
reverse contrast, and mixed contrast configurations. These examples
illustrate how boundary and surface mechanisms can generate percepts
that are highly context-sensitive, including how illusory contours
can be amodally recognized without being seen, how model simple cells
in V1 respond preferentially to luminance discontinuities using
inputs from both LGN ON and OFF cells, how model bipole cells in V2
with two colinear receptive fields can help to complete curved
illusory contours, how short-range simple cell groupings and
long-range bipole cell groupings can sometimes generate different
outcomes, and how model double-opponent, filling-in and boundary
segmentation mechanisms in V4 interact to generate surface brightness
percepts in which filling-in of enhanced brightness and darkness can
occur before the net brightness distribution is computed by
double-opponent interactions.
MAIN MESH HEADINGS:
Contrast Sensitivity/*physiology
Geniculate Bodies/*physiology
Vision, Binocular/*physiology
Visual Cortex/*physiology
ADDITIONAL MESH HEADINGS:
Computer Simulation
Feedback
Forecasting
Human
Models, Neurological
Neural Pathways
NLM PUBMED CIT. ID:
8962825
SOURCE: Vis Neurosci 1995 Nov-Dec;12(6):1027-52
NLM CIT. ID: 95247400
TITLE: Ethambutol alters spinule-type synaptic connections and induces
morphologic alterations in the cone pedicles of the fish retina.
AUTHORS: Kohler K; Zrenner E; Weiler R
AUTHOR AFFILIATION:
Department of Pathophysiology of Vision and Neuroophthalmology,
University Eye Hospital Tubingen, Germany.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
REGISTRY NUMBERS:
74-55-5 (Ethambutol)
ABSTRACT:
PURPOSE. Ethambutol can cause optic neuropathy and deficiencies in
color-opponent visual processing in patients treated for
tuberculosis. In fish, Ethambutol induces color vision deficiencies
similar to those observed in humans and affects color coding in
retinal ganglion cells. Color opponency in fish is mainly mediated by
a horizontal cell feedback onto cones thought to be provided by
spinules. The authors examined whether Ethambutol affects spinules
and is, therefore, able to alter color processing at a distal stage,
that is, at the first synaptic connection within the retina. METHODS.
Ethambutol was injected into the vitreous of either dark- or
light-adapted fish. After drug application, fish were held under
different illumination conditions. Thereafter, the retinas were
dissected and prepared for electron microscopy. Ultrathin tangential
sections of retinas were examined at the level of the outer plexiform
layer. RESULTS. In already light- adapted retinas, a high dose of
Ethambutol (10 mM) reduced the number of spinules by 30%. Ethambutol
application in the dark with subsequent light adaptation resulted in
severe dose-related inhibition of light- induced spinule formation.
In these experiments, low doses (0.1 mM) of Ethambutol caused 40%
inhibition, and high doses (10 mM) caused 70% inhibition. Besides
affecting spinules, Ethambutol occasionally induced a degeneration of
cone pedicles. This neurotoxicity only occurred in cones exposed to
light. CONCLUSIONS. Results show that Ethambutol alters synaptic
connections between horizontal cells and cones in a dose-related
fashion; Ethambutol treatment can be toxic for cone pedicles and can
cause their degeneration; and the rod pathway is not affected by the
drug. This indicates that Ethambutol influences the color-coding
process already at the level of the cone-horizontal cell synapse.
MAIN MESH HEADINGS:
Cones (Retina)/*drug effects
Cones (Retina)/*ultrastructure
Ethambutol/*pharmacology
Neurites/*drug effects
Synapses/*drug effects
ADDITIONAL MESH HEADINGS:
Animal
Carp
Color Perception/drug effects
Dark Adaptation
Dose-Response Relationship, Drug
Injections
Light
Neurites/ultrastructure
Retina/drug effects
Retina/ultrastructure
Synapses/ultrastructure
NLM PUBMED CIT. ID:
7730014
SOURCE: Invest Ophthalmol Vis Sci 1995 May;36(6):1046-55
20
NLM CIT. ID: 95221658
TITLE: An opponent-process interpretation of the anxiolytic effects of single
inhalations of large concentrations of carbon dioxide.
AUTHORS: Ley R
AUTHOR AFFILIATION:
University at Albany, State University of New York 12222.
PUBLICATION TYPES:
CLINICAL TRIAL
JOURNAL ARTICLE
RANDOMIZED CONTROLLED TRIAL
LANGUAGES:
Eng
REGISTRY NUMBERS:
124-38-9 (Carbon Dioxide)
ABSTRACT:
Ten anxiety-disorder outpatients and 10 controls were monitored for
heart rate and self reports of anxiety approximately 1 min before and
1 min after a single full-capacity inhalation of a gas consisting of
either 65% CO2 + 35% O2 or compressed air. Under the CO2 + O2
condition, patients and controls showed almost identical reductions
in anxiety and parallel reductions in heart rate. From an
opponent-process point of view, these reductions were explained by
the acute negative affective state being followed by the hedonically
pleasant state that follows dissipation of CO2. Under the compressed
air condition, only patients showed reductions of anxiety presumably
because in them breathing an unknown gas via an inhalation mask,
raised anxiety, followed by an opponent-process to anxiety after
withdrawal of the mask.
MAIN MESH HEADINGS:
Anxiety Disorders/*therapy
Arousal/*drug effects
Carbon Dioxide/*administration & dosage
ADDITIONAL MESH HEADINGS:
Administration, Inhalation
Adult
Anxiety Disorders/psychology
Blood Pressure/drug effects
Dose-Response Relationship, Drug
Female
Heart Rate/drug effects
Human
Male
Middle Age
NLM PUBMED CIT. ID:
7706507
SOURCE: J Behav Ther Exp Psychiatry 1994 Dec;25(4):301-9
20
NLM CIT. ID: 95221658
TITLE: An opponent-process interpretation of the anxiolytic effects of single
inhalations of large concentrations of carbon dioxide.
AUTHORS: Ley R
AUTHOR AFFILIATION:
University at Albany, State University of New York 12222.
PUBLICATION TYPES:
CLINICAL TRIAL
JOURNAL ARTICLE
RANDOMIZED CONTROLLED TRIAL
LANGUAGES:
Eng
REGISTRY NUMBERS:
124-38-9 (Carbon Dioxide)
ABSTRACT:
Ten anxiety-disorder outpatients and 10 controls were monitored for
heart rate and self reports of anxiety approximately 1 min before and
1 min after a single full-capacity inhalation of a gas consisting of
either 65% CO2 + 35% O2 or compressed air. Under the CO2 + O2
condition, patients and controls showed almost identical reductions
in anxiety and parallel reductions in heart rate. From an
opponent-process point of view, these reductions were explained by
the acute negative affective state being followed by the hedonically
pleasant state that follows dissipation of CO2. Under the compressed
air condition, only patients showed reductions of anxiety presumably
because in them breathing an unknown gas via an inhalation mask,
raised anxiety, followed by an opponent-process to anxiety after
withdrawal of the mask.
MAIN MESH HEADINGS:
Anxiety Disorders/*therapy
Arousal/*drug effects
Carbon Dioxide/*administration & dosage
ADDITIONAL MESH HEADINGS:
Administration, Inhalation
Adult
Anxiety Disorders/psychology
Blood Pressure/drug effects
Dose-Response Relationship, Drug
Female
Heart Rate/drug effects
Human
Male
Middle Age
NLM PUBMED CIT. ID:
7706507
SOURCE: J Behav Ther Exp Psychiatry 1994 Dec;25(4):301-9
NLM CIT. ID: 93340659
TITLE: Extending continuous versus discontinuous conditioned stimuli before
versus after unconditioned stimuli.
AUTHORS: Albert M; Ricker S; Bevins RA; Ayres JJ
AUTHOR AFFILIATION:
Department of Psychology, Concordia College, Amherst, Massachusetts.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
Conditioned suppression was used with rats to study the effects of
extending conditioned stimuli (CSs) before versus after the delivery
of unconditioned stimuli. These extensions are termed B and A
extensions, respectively. Within-group designs were used to compare
the effects of extending CSs when 2-min parts of those CSs were
separated by temporal gaps of 6 min versus a separation of no gap.
The results were as follows: (a) B extensions weakened conditioning
more than did A extensions, with or without gaps; (b) under some
conditions, this asymmetrical effect persisted with extended
training; (c) gaps between 2-min parts of a B extension had no
detectable effect; and (d) under some parameter values, gaps between
2-min parts of an A extension weakened conditioning significantly.
These results are better predicted by the Sometimes Opponent-Process
model (SOP; A. R. Wagner, 1981) than by the
Rescorla-Wagner-Frey-Sears real-time model (J. J. B. Ayres, M.
Albert, & J. C. Bombace, 1987).
MAIN MESH HEADINGS:
*Association Learning
*Attention
*Conditioning, Classical
*Reinforcement Schedule
ADDITIONAL MESH HEADINGS:
Animal
Appetitive Behavior
Inhibition (Psychology)
Male
Rats
Recall
Support, Non-U.S. Gov't
Support, U.S. Gov't, Non-P.H.S.
NLM PUBMED CIT. ID:
8340768
SOURCE: J Exp Psychol Anim Behav Process 1993 Jul;19(3):255-64
NLM CIT. ID: 93179913
TITLE: Effect of SCN lesions on sleep in squirrel monkeys: evidence for
opponent processes in sleep-wake regulation.
AUTHORS: Edgar DM; Dement WC; Fuller CA
AUTHOR AFFILIATION:
Department of Animal Physiology, University of California, Davis
95616.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
MH41477/MH/NIMH
AG05397/AG/NIA
AG06490/AG/NIA
ABSTRACT:
Sleep and wakefulness are governed by both the suprachiasmatic nuclei
of the hypothalamus (SCN), and a sleep homeostatic process; however,
the interaction of these control systems is not well understood. From
rodent studies it has been assumed that the SCN promote neither wake
nor sleep but gate the homeostatic sleep-promoting process. Yet in
humans sleep tendency is lowest during the later waking hours of the
day, and sleep duration can be predicted because of the precise
circadian timing of waking. Thus in primates, the SCN could assure
sleep-wake cycle consolidation by actively promoting or facilitating
wakefulness. To evaluate this hypothesis, we examined the sleep-wake
and sleep-stage patterns of intact and SCN-lesioned (SCNx) squirrel
monkeys maintained in constant light. This diurnal primate has
consolidated sleep and wake patterns more similar to man than
rodents. Sleep-wake, sleep stages, brain temperature, and drinking
circadian rhythms were eliminated, and total sleep time was
significantly increased (4.0 hr, P < 0.01) in SCNx monkeys. However,
total times in deeper stages of non-rapid eye movement (non-REM;
e.g., delta sleep) and REM sleep were not significantly affected by
SCN lesions. Increased total sleep time was associated with a
reduction in subjective day wake consolidation, as evidenced by
substantially shorter wake bout lengths in SCNx monkeys (15 +/- 6
min) as compared to intact monkeys (223 +/- 10 min; P < 0.0001,
ANOVA). These findings show that the SCN influence the regulation of
daily total wake and sleep times, and implicate an alternative
sleep-wake regulatory model in which an SCN-dependent process
actively facilitates the initiation and maintenance of wakefulness
and opposes homeostatic sleep tendency during the subjective day in
diurnal primates.
MAIN MESH HEADINGS:
Sleep/*physiology
Suprachiasmatic Nucleus/*physiology
Wakefulness/*physiology
ADDITIONAL MESH HEADINGS:
Analysis of Variance
Animal
Arousal/physiology
Body Temperature
Circadian Rhythm
Electroencephalography
Male
Reference Values
Saimiri
Support, U.S. Gov't, Non-P.H.S.
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
8441003
SOURCE: J Neurosci 1993 Mar;13(3):1065-79
NLM CIT. ID: 93103543
TITLE: Opponent-process theory and drug conditioning: an assessment for
conditioned stimulant-induced movement.
AUTHORS: Carey RJ; Damianopoulos EN
AUTHOR AFFILIATION:
Department of Psychiatry, SUNY Health Science Center, Syracuse.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
REGISTRY NUMBERS:
0 (Receptors, Dopamine)
1199-18-4 (Oxidopamine)
51-61-6 (Dopamine)
52-86-8 (Haloperidol)
58-00-4 (Apomorphine)
GRANT/CONTRACT ID:
2R01DA0536605/DA/NIDA
ABSTRACT:
Opponent-process theory occupies an important place in drug
conditioning because it accounts for conditioned drug effects which
are opposite to those induced by the drug itself. It has not been
established, however, whether there is an opponent-process component
to stimulant drug induced conditioned effects. In the present study
the unilateral 6-hydroxydopamine (6-OHDA) rat model was used to
examine this issue. Two groups of Sprague-Dawley rats with equivalent
6-OHDA lesions were administered five apomorphine treatments (0.05
mg/kg s.c.) either paired or unpaired to a 10-min test chamber
placement. Apomorphine induced vigorous contralateral rotation and
suppressed all ipsilateral rotation. While the apomorphine-induced
contralateral rotation response can be conditioned to the test
environment cues, the critical test of opponent-process theory in the
present study was whether the opposite response of ipsilateral
rotation would also become conditioned as a latent opponent-process
response to the exteroceptive test environment cues associated with
the apomorphine drug state. The postacquisition saline test for
conditioning showed that the paired group exhibited higher rates of
contralateral and ipsilateral rotation compared to the unpaired
group. In addition, when the animals were subsequently tested with
the dopaminergic receptor antagonist, haloperidol (0.5 mg/kg),
unexpectedly, contralateral rotation was enhanced in the paired
group, whereas, ipsilateral rotation was suppressed in both groups.
While these findings are, in part, compatible with an
opponent-process mechanism, the data supported a simpler explanation;
namely, the mechanism of differential habituation in the two groups
due to a blocking effect of apomorphine on habituation selectively in
the paired group.(ABSTRACT TRUNCATED AT 250 WORDS)
MAIN MESH HEADINGS:
Arousal/*drug effects
Conditioning, Classical/*drug effects
Corpus Striatum/*drug effects
Homeostasis/*drug effects
Laterality/*drug effects
Motor Activity/*drug effects
Oxidopamine/*pharmacology
Receptors, Dopamine/*drug effects
Substantia Nigra/*drug effects
ADDITIONAL MESH HEADINGS:
Animal
Apomorphine/pharmacology
Arousal/physiology
Association Learning/drug effects
Association Learning/physiology
Conditioning, Classical/physiology
Corpus Striatum/physiology
Dominance, Cerebral/drug effects
Dominance, Cerebral/physiology
Dopamine/physiology
Dose-Response Relationship, Drug
Haloperidol/pharmacology
Homeostasis/physiology
Laterality/physiology
Locomotion/drug effects
Locomotion/physiology
Male
Motor Activity/physiology
Neural Pathways/drug effects
Neural Pathways/physiology
Rats
Rats, Sprague-Dawley
Receptors, Dopamine/physiology
Stereotyped Behavior/drug effects
Stereotyped Behavior/physiology
Substantia Nigra/physiology
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
1466780
SOURCE: Behav Brain Res 1992 Nov 15;51(2):139-47
NLM CIT. ID: 93276598
TITLE: Changes in pattern induced flicker colors are mediated by the blue-
yellow opponent process.
AUTHORS: Schramme J
AUTHOR AFFILIATION:
Institut fur Zoologie, Johannes Gutenberg Universitat, Mainz, Germany.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
The colors of Benham's Top [pattern induced flicker colors (PIFCs)]
were matched with color stimuli provided by a computer aided color
mixer. Subjects viewed a series of specifically modified black and
white disks and matched the resulting subjective color with a
comparison field containing the color generated by additive mixing.
Different phase relations between the apparently colored ring and the
surround were tested. The color loci of all PIFCs were found to lie
on a plane in receptor three-space which is given by the axis of the
shortwave receptor excitation and a vector given by combining the
middle and long wave receptor excitation directions in a fixed ratio
of nearly 1:1. From the orientation of this plane it can be deduced
that the blue-yellow opponent process (the blue-on-center cells)
alone accounts for the different PIFCs.
MAIN MESH HEADINGS:
Color Perception/*physiology
ADDITIONAL MESH HEADINGS:
Adult
Color Perception Tests
Female
Human
Light
Male
Pattern Recognition, Visual
Photic Stimulation
Photoreceptors/physiology
NLM PUBMED CIT. ID:
1304090
SOURCE: Vision Res 1992 Nov;32(11):2129-34
NLM CIT. ID: 93276596
TITLE: A bidimensional theory of achromatic color vision.
AUTHORS: Heggelund P
AUTHOR AFFILIATION:
Institute of Neurophysiology, University of Oslo, Norway.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
The theory is based on a perceptive color system where the achromatic
colors are specified by their degree of similarity to the three
qualities white, black and luminous. Black and luminous are treated
as opponent variables. It is assumed that white and luminous/black
are determined by different kinds of visual processes termed the w-
and the b-process. The relationship between these processes and
luminance parameters in a simple disc/ring configuration is derived
from available data. The b-process is related to stimulus contrast in
a simple manner. It is assumed to involve cells with antagonistic
center/surround organization of the receptive field. The w-process is
primarily determined by the local luminance, and it is assumed to
involve cells that lack a center/surround organization of the
receptive field. The w-process has properties similar to the
processes involved in chromatic color vision. The theory can account
for different kinds of psychophysical data on achromatic colors like
data on simultaneous contrast, color scaling, and color constancy.
MAIN MESH HEADINGS:
Color Perception/*physiology
*Models, Biological
ADDITIONAL MESH HEADINGS:
Contrast Sensitivity/physiology
Human
Light
Mathematics
Psychophysics
Psychophysiology
NLM PUBMED CIT. ID:
1304088
SOURCE: Vision Res 1992 Nov;32(11):2107-19
TITLE: Redness from short-wavelength-sensitive cones does not induce
greenness [published erratum appears in Vision Res 1992
Nov;32(11):2199]
AUTHORS: Shevell SK
AUTHOR AFFILIATION:
Department of Psychology, University of Chicago, IL 60637.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY-04802/EY/NEI
ABSTRACT:
According to opponent-colors theory, a reddish surround induces
greenness in a central test field. Color-appearance measurements
verify this with a long-wavelength reddish surround (660 nm) but not
with a short-wavelength reddish surround (440 nm). Surprisingly, a
short- wavelength reddish surround shifts the appearance of a test
toward redness. Four possible explanations are: (1) stray light from
the short- wavelength reddish surround falls in the test area; (2)
receptoral sensitivity changes overwhelm induced greenness from the
surround; (3) a neural process of assimilation, rather than contrast,
to the surrounding light; and (4) short-wavelength-sensitive (S)
cones do not contribute to induced redness/greenness. Chromatic
cancellation experiments confirm the fourth explanation. There was no
change in induced redness/greenness when quantal absorption by only S
cones in the surround was varied by 30-fold (using tritanopic
metamers), even though varying stimulation of S cones strongly
affected the color appearance of the surround. The redness induced by
a short-wavelength surround is accounted for by opponent chromatic
induction mediated by only middle- and long-wavelength-sensitive
cones.
MAIN MESH HEADINGS:
Color Perception/*physiology
Photoreceptors/*physiology
ADDITIONAL MESH HEADINGS:
Dark Adaptation/physiology
Human
Light
Models, Neurological
Photic Stimulation
Spectrophotometry
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
1455727
SOURCE: Vision Res 1992 Aug;32(8):1551-6
TITLE: Redness from short-wavelength-sensitive cones does not induce
greenness [published erratum appears in Vision Res 1992
Nov;32(11):2199]
AUTHORS: Shevell SK
AUTHOR AFFILIATION:
Department of Psychology, University of Chicago, IL 60637.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY-04802/EY/NEI
ABSTRACT:
According to opponent-colors theory, a reddish surround induces
greenness in a central test field. Color-appearance measurements
verify this with a long-wavelength reddish surround (660 nm) but not
with a short-wavelength reddish surround (440 nm). Surprisingly, a
short- wavelength reddish surround shifts the appearance of a test
toward redness. Four possible explanations are: (1) stray light from
the short- wavelength reddish surround falls in the test area; (2)
receptoral sensitivity changes overwhelm induced greenness from the
surround; (3) a neural process of assimilation, rather than contrast,
to the surrounding light; and (4) short-wavelength-sensitive (S)
cones do not contribute to induced redness/greenness. Chromatic
cancellation experiments confirm the fourth explanation. There was no
change in induced redness/greenness when quantal absorption by only S
cones in the surround was varied by 30-fold (using tritanopic
metamers), even though varying stimulation of S cones strongly
affected the color appearance of the surround. The redness induced by
a short-wavelength surround is accounted for by opponent chromatic
induction mediated by only middle- and long-wavelength-sensitive
cones.
MAIN MESH HEADINGS:
Color Perception/*physiology
Photoreceptors/*physiology
ADDITIONAL MESH HEADINGS:
Dark Adaptation/physiology
Human
Light
Models, Neurological
Photic Stimulation
Spectrophotometry
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
1455727
SOURCE: Vision Res 1992 Aug;32(8):1551-6
TITLE: Redness from short-wavelength-sensitive cones does not induce
greenness [published erratum appears in Vision Res 1992
Nov;32(11):2199]
AUTHORS: Shevell SK
AUTHOR AFFILIATION:
Department of Psychology, University of Chicago, IL 60637.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY-04802/EY/NEI
ABSTRACT:
According to opponent-colors theory, a reddish surround induces
greenness in a central test field. Color-appearance measurements
verify this with a long-wavelength reddish surround (660 nm) but not
with a short-wavelength reddish surround (440 nm). Surprisingly, a
short- wavelength reddish surround shifts the appearance of a test
toward redness. Four possible explanations are: (1) stray light from
the short- wavelength reddish surround falls in the test area; (2)
receptoral sensitivity changes overwhelm induced greenness from the
surround; (3) a neural process of assimilation, rather than contrast,
to the surrounding light; and (4) short-wavelength-sensitive (S)
cones do not contribute to induced redness/greenness. Chromatic
cancellation experiments confirm the fourth explanation. There was no
change in induced redness/greenness when quantal absorption by only S
cones in the surround was varied by 30-fold (using tritanopic
metamers), even though varying stimulation of S cones strongly
affected the color appearance of the surround. The redness induced by
a short-wavelength surround is accounted for by opponent chromatic
induction mediated by only middle- and long-wavelength-sensitive
cones.
MAIN MESH HEADINGS:
Color Perception/*physiology
Photoreceptors/*physiology
ADDITIONAL MESH HEADINGS:
Dark Adaptation/physiology
Human
Light
Models, Neurological
Photic Stimulation
Spectrophotometry
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
1455727
SOURCE: Vision Res 1992 Aug;32(8):1551-6
NLM CIT. ID: 89168094
TITLE: Prolonged morphine self-administration and addiction liability.
Evaluation of two theories in a bone marrow transplant unit.
AUTHORS: Chapman CR; Hill HF
AUTHOR AFFILIATION:
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
REGISTRY NUMBERS:
57-27-2 (Morphine)
GRANT/CONTRACT ID:
CA 38552/CA/NCI
CA 18092/CA/NCI
ABSTRACT:
The technology for patient intravenous self-administration of morphine
has been successfully implemented in postoperative and other clinical
settings and can be used with terminal patients who experience pain.
The question of whether patients who use such instrumentation will be
vulnerable to over-medication or development of addiction has not
been addressed. This report reviews two competing theories that bear
upon this question and tests their predictions about
self-administration of morphine for pain relief using data obtained
from patients in a bone marrow transplant unit. The first, Opponent
Process Theory, predicts escalating drug use and the development of
addictive behavior in patients who self-administer morphine. The
second, Control Theory, predicts that patients will self-regulate
pain effectively by administering morphine without developing
problems of medication abuse or addiction. Patients
self-administering morphine for 2 weeks were compared to controls who
received the drug via routine staff-controlled continuous infusion
procedures. Self-administering patients used significantly less
morphine than controls and still achieved the same amount of pain
control; moreover, they terminated drug use sooner than controls. The
predictions based upon Opponent Process Theory were not supported in
these marrow transplant patients, but Control Theory accounted well
for the outcomes. These results support the assumption that
self-administration of opioids in a medical setting does not put
patients at risk for over-medication or addiction.
MAIN MESH HEADINGS:
Morphine/*administration & dosage
Morphine Dependence/*psychology
Pain/*drug therapy
Self Administration/*psychology
ADDITIONAL MESH HEADINGS:
Adult
Combined Modality Therapy/adverse effects
Drug Administration Schedule
Female
Human
Male
Mouth Mucosa
Palliative Care/psychology
Risk
Stomatitis/drug therapy
Stomatitis/etiology
Support, Non-U.S. Gov't
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
2466551
SOURCE: Cancer 1989 Apr 15;63(8):1636-44
NLM CIT. ID: 89208233
TITLE: Hedonic interactions of medial prefrontal cortex and nucleus
reticularis gigantocellularis.
AUTHORS: Miserendino MJ; Coons EE
AUTHOR AFFILIATION:
Department of Psychology, New York University, NY 10003.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
It has been shown that 'pure reward' and 'reward-escape' sites in the
lateral hypothalamus (LH) of rats respectively ameliorate and
exacerbate nucleus reticularis gigantocellularis (NGC) stimulation-
induced aversion52. Conversely, the present studies found that
'rewarding' medial prefrontal cortex (MPFC) stimulation increased
escape from NGC stimulation regardless of whether the MPFC site
tested was 'pure reward' or 'reward-escape' in type. This suggested
that a simple algebraic summation model of positive and negative
affective processes may not adequately describe the NGC-MPFC
interaction. In a subsequent study, rats were observed both to
barpress less to obtain, and more to escape from, 'rewarding' MPFC
stimulation during continuous NGC stimulation, supporting the
hypothesis that the observed MPFC stimulation-mediated increase in
NGC stimulation escape reflected an exacerbation of aversion.
Finally, NGC stimulation was seen to increase barpressing to obtain
'subreward' MPFC current trains, indicating a potentiation of the
reward value of such current. Results of this series of studies
suggests a hedonic interaction model of NGC and MPFC characterized by
reciprocal neuromodulation. The model is conceptualized as a 'neural
opponent process' subserving affective 'balance' and 'feature
enhancement', and its possible relevance to the putative role of the
MPFC in cocaine use is discussed.
MAIN MESH HEADINGS:
Escape Reaction/*physiology
Frontal Lobe/*physiology
Medulla Oblongata/*physiology
*Reward
ADDITIONAL MESH HEADINGS:
Action Potentials
Animal
Electric Stimulation
Evoked Potentials
Female
Habituation (Psychophysiology)
Rats
Rats, Inbred Strains
NLM PUBMED CIT. ID:
2706517
SOURCE: Brain Res 1989 Apr 3;483(2):233-50
NLM CIT. ID: 90045157
TITLE: Opponent process theory of motivation: neurobiological evidence from
studies of opiate dependence.
AUTHORS: Koob GF; Stinus L; Le Moal M; Bloom FE
AUTHOR AFFILIATION:
Department of Neuropharmacology, Research Institute of Scripps Clinic,
La Jolla, CA 92037.
PUBLICATION TYPES:
JOURNAL ARTICLE
REVIEW
REVIEW, TUTORIAL
LANGUAGES:
Eng
REGISTRY NUMBERS:
0 (Narcotics)
GRANT/CONTRACT ID:
DA04043/DA/NIDA
AA05420/AA/NIAAA
ABSTRACT:
One hypothetical model for a mechanism of drug dependence involves the
development of an adaptive process that is initiated to counter the
acute effects of the drug. This adaptive process persists after the
drug has been cleared from the brain, leaving an opposing reaction
unopposed (abstinence signs). From a motivational perspective a
particularly attractive hypothesis has been that of opponent process
theory (32). Here many reinforcers elicit positive affective and
hedonic processes that are opposed by negative affective and hedonic
processes. Thus the intense pleasure of the opiate drug "rush" or
"high" would be opposed by aversive withdrawal symptoms. The present
paper presents neurobiological evidence to support the opponent
process concept and suggests neural circuitry that may be involved.
The region of the nucleus accumbens in the forebrain of the rat has
been shown to be a particularly sensitive substrate not only for the
acute reinforcing properties of opiate drugs, but also for the
response disruptive effects of opiate antagonists in opiate dependent
rats. This region also appears to be particularly sensitive to the
aversive stimulus effects of opiate antagonists using a place
aversion measure in dependent rats. These results suggest that the
region of the nucleus accumbens and its neural circuitry may be an
important neural substrate for both the positive and negative
motivational aspects of drug dependence.
MAIN MESH HEADINGS:
Brain/*physiopathology
*Models, Biological
*Motivation
Opioid-Related Disorders/*physiopathology
ADDITIONAL MESH HEADINGS:
Animal
Human
Narcotics/administration & dosage
Self Administration
Substance Withdrawal Syndrome/physiopathology
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
2682399
SOURCE: Neurosci Biobehav Rev 1989 Summer-Fall;13(2-3):135-40
NLM CIT. ID: 88214287
TITLE: Contextual conditioning with massed versus distributed unconditional
stimuli in the absence of explicit conditional stimuli.
AUTHORS: Fanselow MS; Tighe TJ
AUTHOR AFFILIATION:
Department of Psychology, Dartmouth College, Hanover, New Hampshire
03755.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
MH39786/MH/NIMH
ABSTRACT:
Rats received unsignaled shocks in an observation chamber, with
different groups varying with respect to time between shocks. Twenty-
four hours later the rats were returned to the observation chamber
for a test of conditioning to contextual stimuli. The freezing
response served as the dependent variable. In Experiment 1 we found
that distributed shock trials (60 s) resulted in more context
conditioning than did massed trials (3 s or 16 s). Experiment 2
replicated this intertrial interval (ITI) effect when total time in
the context was equated for the massed and distributed groups. The
observed beneficial effect of distributed practice for conditional
stimuli arises because of decreased contextual conditioning with
longer ITIs (e.g., Gibbon & Balsam, 1981; Rescorla & Wagner, 1972).
Although the basic effect of enhanced performance with longer ITIs is
consistent with Wagner's rehearsal model (e.g., 1978), three findings
argue against such an account. First, posttrial stimulation did not
reduce the benefit obtained from distributed trials (Experiment 3).
Second, intertrial distractors did not improve performance of the
animals subjected to massed trials (Experiment 4). And third, the ITI
effect was not eliminated when conditioning was brought to its
asymptote (Experiment 5). The overall pattern of data is consistent
with an opponent-process account suggesting that in addition to
supporting conditioning, the unconditional stimulus (US) activates a
B-state capable of reducing the impact of the next US and that this
B-state lasts longer than 16s but decays before 60 s.
MAIN MESH HEADINGS:
*Association Learning
*Conditioning, Classical
*Learning
*Practice (Psychology)
*Social Environment
ADDITIONAL MESH HEADINGS:
Animal
Electroshock
Female
Motor Activity
Rats
Rats, Inbred Strains
Support, Non-U.S. Gov't
Support, U.S. Gov't, Non-P.H.S.
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
3367103
SOURCE: J Exp Psychol Anim Behav Process 1988 Apr;14(2):187-99
NLM CIT. ID: 91197759
TITLE: Neuropharmacological analysis of the role of indoleamine-accumulating
amacrine cells in the rabbit retina.
AUTHORS: Brunken WJ; Daw NW
AUTHOR AFFILIATION:
Department of Cell Biology and Physiology, Washington University, St.
Louis.
PUBLICATION TYPES:
JOURNAL ARTICLE
REVIEW
REVIEW, TUTORIAL
LANGUAGES:
Eng
REGISTRY NUMBERS:
0 (Receptors, Serotonin)
0 (Serotonin Antagonists)
50-67-9 (Serotonin)
ABSTRACT:
In order to elucidate the role of putative indoleaminergic amacrine
cells in visual processing, we have employed pharmacological agents
specific for the two classes of serotonin receptor, 5-HT2 and 5-HT1,
which have been identified in both the retina and brain. Perfusion of
the rabbit retina with 5-HT2 selective antagonists decreases the ON-
excitation of all classes of ganglion cell as well as the spontaneous
activity of these cells. The effect on OFF-responses depends on the
cell type: OFF-excitation of center-surround brisk and sluggish cells
is increased or not affected by these drugs, but OFF excitation of
ON/OFF direction selective cells is reduced. No disruption of the
trigger features of direction selective or orientation selective
cells was discovered, suggesting that indoleaminergic amacrine cells
do not play a role in the generation of the complex properties of
these cells. 5-HT1 receptors are heterogeneous and classified as a,
b, or c subtypes. Since no selective antagonists are available for
these sites, we have employed specific agonists. The most specific of
these are for the 5-HT1A receptor. Perfusion with these agonists had
physiological effects similar to those with perfusion of 5-HT2
antagonists. Thus, we have suggested that these two classes of
serotonin receptors mediate opponent processes in the neural pathway.
Since indoleaminergic cells make reciprocal synaptic connections with
rod bipolar cell terminals, which are depolarizing in the rabbit
retina, we hypothesize that 5-HT2 receptors facilitate the synaptic
transmission from the depolarizing rod bipolar cell thus facilitating
ON-excitation in the retinal network while 5-HT1A receptors mediate
an inhibitory process. Similar self- opponent processing appears to
take place in the hypothalamic and hippocampal serotonergic systems
as well as in the dopaminergic retinal system. Thus, it is likely
that this organization is a general feature of monoamine signal
transmission in the central nervous system.
MAIN MESH HEADINGS:
Retina/*cytology
Serotonin/*physiology
ADDITIONAL MESH HEADINGS:
Animal
Electrophysiology
Perfusion
Rabbits
Receptors, Serotonin/drug effects
Receptors, Serotonin/physiology
Retina/physiology
Retinal Ganglion Cells/physiology
Serotonin Antagonists/diagnostic use
Visual Pathways/physiology
NLM PUBMED CIT. ID:
3154800
SOURCE: Vis Neurosci 1988;1(3):275-85
NLM CIT. ID: 87225153
TITLE: Suppressive rod-cone interaction in distal vertebrate retina:
intracellular records from Xenopus and Necturus.
AUTHORS: Frumkes TE; Eysteinsson T
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
EY-05984/EY/NEI
ABSTRACT:
The influence of dim diffuse adapting fields upon the sensitivity to
focal photic stimulation was studied by means of intracellular
recording in retinal neurons of the south african clawed frog,
Xenopus and the mudpuppy, Necturus. In cones and in most horizontal
and bipolar cells lacking color opponency, dim diffuse backgrounds
have little influence upon the response to diffuse flicker of low
(less than 2 Hz) temporal frequencies; however, with small diameter
test probes of higher temporal frequencies, presentation of dim
backgrounds enhance the peak-to-peak amplitude of responses to
sinusoidal flicker by as much as 800%. This background enhancement
effect adheres to the spectral sensitivity of the green-absorbing rod
photopigment, and appears to be largely independent of the influence
of the adapting field upon cone photopigment or ambient membrane
potential in the recorded neuron. This effect cannot be obtained with
rod-driven flicker responses. We designate this background influence
on flicker, suppressive rod-cone interaction (SRCI) and attribute it
to a tonic suppressive (probably inhibitory) influence of rods upon
cone pathways that is removed by rod light adaptation. SRCI is also
observed in the response of most sustained ON and OFF ganglion cells.
However, no corresponding effect occurs in rods, color-opponent
second-order neurons, ON-OFF amacrine cells, or most ON-OFF ganglion
cells. The spatial and temporal limitations of SRCI observed by means
of intracellular recording in amphibians are very similar to those
documented by means of psychophysical or electroretinogram (ERG)
procedures in a wide variety of species including humans (2, 4, 11,
22, 23, 29). SRCI most probably reflects a process that is mediated
by horizontal cells. The specifics of the underlying mechanism remain
unclear.
MAIN MESH HEADINGS:
*Adaptation, Ocular
Photoreceptors/*physiology
Vision/*physiology
ADDITIONAL MESH HEADINGS:
Animal
Cell Communication
Comparative Study
Necturus maculosus
Neurons/physiology
Retina/physiology
Retinal Ganglion Cells/physiology
Species Specificity
Support, Non-U.S. Gov't
Support, U.S. Gov't, Non-P.H.S.
Support, U.S. Gov't, P.H.S.
Xenopus laevis
NLM PUBMED CIT. ID:
3585472
SOURCE: J Neurophysiol 1987 May;57(5):1361-82
NLM CIT. ID: 86173943
TITLE: Evidence for an underlying opponent process during morphine elicited
hyperactivity in the hamster.
AUTHORS: Schnur P; Raigoza VR
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
REGISTRY NUMBERS:
0 (Hypnotics and Sedatives)
465-65-6 (Naloxone)
57-27-2 (Morphine)
GRANT/CONTRACT ID:
RR-08197-03/RR/NCRR
ABSTRACT:
Two experiments investigated the effects of naloxone on morphine
elicited hyperactivity in the hamster. In Experiment 1, naloxone (0.4
mg/kg) administered two hours after morphine (15 mg/kg) produced
sedation in animals running at high rates under the influence of
morphine. Saline control animals running at comparable rates were
unaffected by naloxone. In Experiment 2, naloxone administered two
hours after morphine converted morphine elicited hyperactivity into
sedation. These results are discussed in terms of a modified dual-
action hypothesis which holds that morphine elicited hyperactivity
masks an underlying opponent process.
MAIN MESH HEADINGS:
Hyperkinesis/*chemically induced
*Morphine
Naloxone/*pharmacology
ADDITIONAL MESH HEADINGS:
Animal
Drug Tolerance
Female
Hamsters
Hypnotics and Sedatives
Kinetics
Mesocricetus
Morphine/pharmacology
Motor Activity/drug effects
Naloxone/administration & dosage
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
3959756
SOURCE: Life Sci 1986 Apr 7;38(14):1323-9
NLM CIT. ID: 87067862
TITLE: Opposing heart rate reactions associated with behavioral states of
excitation and inhibition.
AUTHORS: Fitzgerald RD; Stainbrook GL
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
GRANT/CONTRACT ID:
HD-10034/HD/NICHD
HLO-7332
ABSTRACT:
Following the development of an excitatory bradycardia conditioned
response (CR) to a CS+ paired with a shock US on Day 1, three groups
of rats were given one of three inhibitory training procedures on Day
2 with a different CS (CS-). Then on Day 3 the inhibitory capacity of
each CS- was examined on a modified combined cue test in which CS-
was given slightly before CS+ and on a reversal conditioning test in
which CS- was now paired with the US. The three inhibitory procedures
consisted of CS- alone (CSA) trials, explicitly unpaired (EUP) CS-
and US trials, and truly random (TR) CS- and US trials. During
inhibitory training, the bradycardia CR to CS+ was replaced with a
tachycardia reaction to CS- in the EUP group but not in the other
groups. Subsequent to inhibitory training the EUP group and to some
extent also the TR group showed a decrement in the excitatory
bradycardia response to CS+ when compared to the robust HR slowdowns
displayed by the CSA group. It was suggested, within the context of
opponent process theory, that the separate USs given the EUP and TR
groups (especially the former) during inhibitory training may have
led to conditioning of inhibitory tendencies to CS- and that these in
turn generalized and decremented previous established bradycardia
responding to CS+ and the development of a new bradycardia to CS-
during reversal conditioning.
MAIN MESH HEADINGS:
Conditioning, Classical/*physiology
*Heart Rate
ADDITIONAL MESH HEADINGS:
Animal
Behavior, Animal/physiology
Electrocardiography
Female
Rats
Support, Non-U.S. Gov't
Support, U.S. Gov't, P.H.S.
NLM PUBMED CIT. ID:
3786501
SOURCE: Physiol Behav 1986;38(1):5-9
NLM CIT. ID: 91084432
TITLE: Form from motion parallax and form from luminance contrast: vernier
discrimination.
AUTHORS: Regan D
AUTHOR AFFILIATION:
Department of Ophthalmology, Dalhousie University, Halifax, Canada.
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
Eng
ABSTRACT:
Some objects are perfectly camouflaged when stationary, but are
clearly visible when moving; the boundaries of such an object are
defined entirely by motion parallax. Little is known about the eye's
ability to make spatial discriminations between motion-defined
objects. In this study, subjects viewed a pseudo-random pattern of
dots within which a camouflaged bar was made visible by relative
motion of dots. Vernier acuity for the motion-defined bar was 27-45
sec arc for three subjects, much less than the interdot separation of
360 sec arc, much less than the 2 deg receptive field size for
motion, and comparable with the foveal intercone separation of 30 sec
arc. It is proposed that an opponent-orientation process and an
opponent-position process can both contribute to vernier judgements
for motion-defined objects. Real-world motion contrast commonly
confounds the following cues for figure-ground segregation: (1)
different texture velocities on either side of the figure's boundary;
(2) in any given time interval, texture in figure and ground moves
different distances; and (3) texture continually appears and
disappears along the figure's boundary. When cues (2) and (3) were
eliminated, thus ensuring figure-ground segregation was achieved
entirely by motion-sensitive neural elements, vernier acuity was 44
+/- 5 sec arc compared with 36 +/- 8 sec arc for a dotted bar defined
by luminance contrast. Conclusion: Vernier acuity for a dotted bar
whose boundary was defined entirely by motion-sensitive neural
elements was similar to vernier acuity for a dotted bar whose
boundary was defined by luminance contrast.
MAIN MESH HEADINGS:
Contrast Sensitivity/*physiology
*Form Perception
*Light
*Motion Perception
Vision Disparity/*physiology
ADDITIONAL MESH HEADINGS:
Human
Support, Non-U.S. Gov't
Support, U.S. Gov't, Non-P.H.S.
Visual Acuity
NLM PUBMED CIT. ID:
3153787
SOURCE: Spat Vis 1986;1(4):305-18
