The effects of neonatal ethanol and/or cocaine exposure on isolation-induced ultrasonic vocalizations.
Isolation-induced ultrasonic vocalizations (USVs) are emitted by young rat pups when isolated from their dam and conspecifics. These USVs play an important role in maternal/offspring interactions, and have been used as an indicator of response to stress and isolation. This study examined the effects of neonatal ethanol and/or cocaine exposure on USVs in neonatal rats. The neonatal exposure paradigm serves as a model for the "human third trimester of pregnancy" in terms of CNS development. There were five treatment groups including an artificially reared (AR) ethanol-exposed group (6 g/kg/day), an AR cocaine-exposed group (60 mg/kg/day), an AR ethanol- and cocaine-exposed group (6 g/kg/day+60 mg/kg/day), an AR isocaloric control, and a normally reared control. Both groups that received ethanol took longer to vocalize, and displayed fewer vocalizations than non-ethanol-exposed pups when tested on clean bedding (Experiment 1) or on chips from the nest of a lactating dam (Experiment 2). These results suggest that neonatal ethanol exposure alters the pup's immediate response to isolation. This could have direct effects on maternal/infant interactions, and might help explain some of the long-term effects of ethanol exposure on social behaviors.
Barron
S
S
Psychology Department, University of Kentucky, Kastle Hall, Room 208, Lexington, KY 40506-0044, USA. sbarron@pop.uky.edu
Segar
T M
TM
Yahr
J S
JS
Baseheart
B J
BJ
Willford
J A
JA
D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects; D003042:Cocaine / Q000633:toxicity*; D000431:Ethanol / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000187:drug effects*
D000431:Ethanol; D003042:Cocaine