Thanks that's good data. I stand corrected. larry
At 04:47 PM 4/2/02 -0500, you wrote: > > Todd, > > > > Infants do not have a fully developed nervous system. For instance, > > mylinization, how the major nerves and nerve pathways become electrically > > insulated, isn't complete until after 18 on the average. > >"Lack of myelination has been proposed as an index of the lack of maturity >in the neonatal nervous system30 and is used frequently to support the >argument that premature or full-term neonates are not capable of pain >perception.9-19 However, even in the peripheral nerves of adults, >nociceptive impulses are carried through unmyelinate (C-polymodal) and >thinly myelinated (A-delta) fibers.31 Incomplete myelination merely implies >a slower conduction velocity in the nerves or central nerve tracts of >neonates, which is offset completely by the shorter interneuron and >neuromuscular distances traveled by the impulse.32 Moreover, quantitative >neuroanatomical data have shown that nociceptive nerve tracts in the spinal >cord and central nervous system undergo complete myelination during the >second and third trimesters of gestation. Pain pathways to the brain stem >and thalamus are completely myelinated by 30 weeks; whereas the >thalamocortical pain fibers in the posterior limb of the internal capsule >and corona radiata are myelinated by 37 weeks.33" > > > Moreover pain > > perception is also a matter of experience and interpretation. so if you > > don't have the mechanism for the pain, its very difficult to define it as > > such. > >The persistence of specific behavioral changes after circumcision in >neonates implies the presence of memory. In the short term, these behavioral >changes may disrupt the adaptation of newborn infants to their postnatal >environment,174-176 the development of parent-infant bonding, and feeding >schedules.182,182 In the long term, painful experiences in neonates could >possibly lead to psychological sequelae,22 since several workers have shown >that newborns may have a much greater capacity for memory than was >previously thought.183-186 > >"Other responses in newborn infants are suggestive of integrated emotional >and behavioral responses to pain and are retained in memory long enough to >modify subsequent behavior patterns." > > >These are from: > >PAIN AND ITS EFFECTS IN THE HUMAN NEONATE AND FETUS >K.J.S. ANAND, M.B.B.S., D.PHIL., AND P.R. HICKEY, M.D > From the Department of Anesthesia, Harvard Medical School, and Children's >Hospital, Boston. > >As printed in: >NEW ENGLAND JOURNAL OF MEDICINE. Vol. 317 No 21: Pages 1321-1329, 19 >November 1987. > > ______________________________________________________________________ Get the mailserver that powers this list at http://www.coolfusion.com Archives: http://www.mail-archive.com/cf-community@houseoffusion.com/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
