The effects of neonatal ethanol and/or cocaine exposure on isolation-induced ultrasonic vocalizations

• Published in: Pharmacology, biochemistry and behavior biochemistry and behavior, 2000-09, Vol.67 (1), p.1-9
• Main Authors: Barron, Susan, Segar, Tracy M, Yahr, Joshua S, Baseheart, Bryan J, Willford, Jennifer A
• Format: Article
• Language: English
• Subjects: Alcoholism and acute alcohol poisoning; Animals; Animals, Newborn; Biological and medical sciences; Body Weight - drug effects; Cocaine - toxicity; Drug addictions; Ethanol - toxicity; Medical sciences; Neonatal cocaine exposure; Neonatal ethanol exposure; Polydrug exposure; Rats; Rats, Sprague-Dawley; Reaction Time - drug effects; Social behaviors; Third trimester drug effects; Toxicology; Ultrasonic vocalizations; Ultrasonics; vocalization; Vocalization, Animal - drug effects
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/S0091-3057(00)00304-X

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.