Noradrenaline and partial reinforcement in rats.

Abstract

Lesions of the dorsal nonadrenergic bundle produced by 6-hydroxydopamine, which depleted telencephalic noradrenaline [norepinephrine] by over 95%, produced resistance to extinction in animals trained on a continuously reinforced schedule for food reward but not to alter the extinction rate after partial reinforcement training. The dorsal bundle extinction effect reported previously was confirmed but it is probably confined to continuously reinforced situations. The pattern of results was consistent with a role for the dorsal bundle in attentional processes but appears to contradict the predictions required if the dorsal bundle were to have a role in frustrative nonreward.