Behavioral effects of chronic cocaine treatment in the week-old rat pup.
Chronic treatment of adult animals with cocaine results in sensitization to some behavioral effects and tolerance to others but there are few reports on the effects of chronic stimulants during early development. The present experiments assessed the development of cocaine-induced alterations in locomotor activity and separation induced ultrasonic vocalization, a fundamental behavior of infant rats. The first study demonstrated a dose dependent suppression of ultrasounds in naive pups at 7 days of age that lasted at least 60 min and that was accompanied by a dose dependent increase in locomotion. To assess chronic effects, pups were injected with cocaine (5.0-30.0 mg/kg) twice daily from ages 1 to 7 days and then tested at 7, 8 and 10 days of age for vocalization in response to isolation from the dam and littermates. There were minimal effects on baseline levels of crying, but following chronic treatment with cocaine, pups showed generally higher levels of ultrasounds when tested with an acute challenge of cocaine at 7 and 8 days of age. In chronically treated pups locomotor activity was increased during baseline tests. At 10 days of age, 3 days after the last treatment with cocaine, in the highest dose treatment condition, there was an exaggerated reduction of ultrasounds when tested with a littermate. The results demonstrate that chronic exposure to cocaine during early development disrupts the normal regulation of a developmentally important socially mediated behavior.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기