Alpha-flupenthixol-induced hyperactivity by chronic dosing in rats.

Socially reared and isolation-reared rats treated chronically since weaning with alpha-flupenthixol showed elevated levels of spontaneous locomotor activity compared with control treated rats. However, chronic apomorphine treatment had no effect on spontaneous locomotor activity. Chronic alpha-flupenthixol treatment enhanced stereotyped behaviour after 1.5 mg/kg d-amphetamine or 0.5 mg/kg apomorphine in the socially reared condition. 'Spontaneous stereotypies' were also observed in the chronic alpha-flupenthixol-treated animals. Chronic apomorphine treatment did not affect stereotyped responding. The results are discussed in terms of 'behavioural supersensitivity'.