Effects of under nutrition during suckling on the behavioural responses of weanling rats to SCH23390

Under nutrition during critical periods of development may change the behavioural responses of rats to centrally acting drugs. We examined the effects of under nutrition during suckling on the behavioural responses of 21-days-old rats to the DI antagonist SCH23390 (0, 0.3, 0.6 and 1.2 mg kg(-1)). Locomotion and catalepsy were assessed at 25 min, 1 h 10 min, 1 h 55 min and 2 h 40 min after drug administration on two consecutive days. SCH23390 induced a similar inhibition of locomotor activity in both normal and under-nourished animals. On the other hand, SCH23390-induced catalepsy was reversed differently in undernourished animals as compared to normal animals with resulting lower catalepsy scores at the 1 h 55 min and 2 h 40 min assessments for the under-nourished animals on day 1, but not on day 2. We suggest that the behavioural effects of SCH23390 are less persistent in under-nourished rats, possibly due to a change in drug pharmacokinetics, as compared to well-nourished rats.