Opioid-dependent behaviors in infant rats: effects of prenatal exposure to ethanol.
Pregnant rats were given diets containing either 5% ethanol, an isocaloric (pair-fed) diet, or casein pellets. Offspring were tested at postnatal day 10 for isolation-induced ultrasonic vocalizations and subsequent stress-induced analgesia. Rats prenatally exposed to ethanol vocalized significantly less in the five minutes during isolation. The opiate, morphine, caused a greater suppression of vocalizations in alcohol-exposed pups compared to controls, while the increased calling normally seen with the opiate antagonist, naltrexone, was attenuated. In a test in which the pup withdraws a paw from a hot plate (48 degrees C), prenatal alcohol offspring demonstrated baseline latencies (no isolation) similar to controls but had greatly attenuated responses in their isolation-induced analgesia. Since both vocalization and analgesia responses have been determined to be modulated by the endogenous opioid system, the aberrant responses of the prenatal-ethanol-exposed offspring can be interpreted as failures to respond by opioid release/secretion to appropriate stimuli.
Kehoe
P
P
Trinity College, Hartford, CT.
Shoemaker
W
W
D000375:Aging / Q000378:metabolism; D000698:Analgesia; D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D001522:Behavior, Animal / Q000187:drug effects*; D001724:Birth Weight / Q000187:drug effects; D004032:Diet; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D009020:Morphine / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects; D009293:Opioid-Related Disorders / Q000523:psychology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains; D012934:Social Isolation; D013315:Stress, Psychological / Q000503:physiopathology; D014828:Vocalization, Animal / Q000187:drug effects
D000431:Ethanol; D009271:Naltrexone; D009020:Morphine