?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Gastric+vagotomy+blocks+opioid+analgesia+enhancement+produced+by+placenta+ingestion&rft.creator=Tarapacki%2C+J.+A.&rft.creator=Thompson%2C+A.+C.&rft.creator=Kristal%2C+Dr.+Mark+B.&rft.subject=Physiological+Psychology&rft.subject=Behavioral+Neuroscience&rft.subject=Neurochemistry&rft.description=Ingestion+of+amniotic+fluid+or+placenta+by+rats+has+been+shown+to+enhance+opioid-mediated+analgesia+induced+by+morphine+injection%2C+footshock%2C+vaginal%2Fcervical+stimulation%2C+or+late+pregnancy.+This+enhancement+by+ingestion+appears+to+be+specific+to+the+central+actions+of+opioids.+The+present+study+was+designed+to+examine+the+possibility+that+information+traveling+via+the+vagus+nerve+might+be+involved+in+mediating+this+effect.+Rats+that+had+undergone+either+selective+gastric+vagotomy+or+sham+vagotomy+were+injected+with+either+morphine+sulfate+or+vehicle+and+fed+either+placenta+or+a+meat+control.+Enhancement+was+observed+in+rats+that+had+undergone+sham+vagotomy+but+not+in+those+that+had+undergone+gastric+vagotomy.+These+results+support+an+interpretation+of+vagal+involvement+in+the+enhancement+of+opioid-mediated+analgesia+by+placenta.&rft.publisher=Pergamon+Press&rft.date=1992&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F5800%2F1%2Fvagotomy.pdf&rft.identifier=++Tarapacki%2C+J.+A.+and+Thompson%2C+A.+C.+and+Kristal%2C+Dr.+Mark+B.++(1992)+Gastric+vagotomy+blocks+opioid+analgesia+enhancement+produced+by+placenta+ingestion.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F5800%2F