[The effects of dopaminergic agents on the self-stimulation of the lateral hypothalamus and on dopamine metabolism in the brain of isolated rats with a disrupted ventral tegmental area].

Male Wistar rats were socially isolated from the 17th day of birth. Ventral tegmental area (VTA) of a half of the 17th-day rats was unilaterally damaged with intrastructural administration of kainic acid. In adult rats (both raised in groups and in isolation) amphetamine (1 mg/kg) facilitated self-stimulation of the lateral hypothalamus (by 37%). Social isolation increased the sensitivity of dopaminergic system only in rats with VTA lesions which was manifested in promoting self-stimulation after administration of amphetamine, though the level and turnover of tegmental dopamine was decreased. 6-Hydroxydopamine (75 mcg intracisternally), a catecholaminergic neurotoxin, significantly inhibited self-stimulation in isolated rats and decreased catecholamine levels in the lateral hypothalamus. The neurotoxic effect of 6-hydroxydopamine was abolished by amphetamine, probably, owing to enhancement of the functional activity of parabiotically living neuronal structures of the mesocorticolimbic dopaminergic system of the brain.