Chronic neonatal treatment with CGS 8216: effects on the behaviour of adolescent rats.

ABSTRACT

The behaviour of male adolescent rats was studied after neonatal administration of CGS 8216 (2.5 or 10 mg/kg/day). The pups were cross-fostered, and drug treatment (in a split-litter design) lasted from postnatal day 7 to day 28; behavioural tests began on day 31. In the social interaction test, neonatally-treated adolescents displayed an unusual profile of behaviour that was the opposite to the profile caused by acute CGS 8216 in adults. Their response to challenge doses of CGS 8216 was not significantly different from that of neonatal controls. In the holeboard test of exploratory behaviour, there was little sign of effects of the neonatal treatment, and the response to challenge doses of Ro 15-1788 or chlordiazepoxide was not differentially affected. However, neonatally-treated animals were less sensitive to the convulsant effects of pentylenetetrazole and picrotoxin. Lasting effects of neonatal CGS 8216 have been detected in adults; the effects seen in adolescents appear not to be identical, since a proconvulsant effect occurs in adults.