The effects of amphetamine or caffeine on the response to glucoprivation in rats with rostral zona incerta lesions.

Lesions in the rostral zona incerta (ZI) of male albino rats severely impaired feeding responses to 2-deoxy-D-glucose (2DG) and drinking responses to hypertonic saline during the first month after surgery. There was evidence of recovery 6 months after surgery but the magnitude of the improvement was small and severe impairments persisted in most subjects. A small but significant deficit in the feeding response to insulin persisted unabated after the 6-month recovery period. Caffeine or amphetamine pretreatment, but not apomorphine, increased ad lib feeding as well as the response to low doses of 2DG in rats with ZI lesions as well as in controls. The increased feeding response to 2DG after caffeine or amphetamine was larger than the sum of the effects of 2DG alone plus the effect of caffeine or amphetamine alone.