Intrahypothalamic microinjections of noradrenaline with and without induction of the alimentary drive as a reward in a T maze learning in rats.

Noradrenaline injected into the perifornical region of the anterior part of the lateral hypothalamus in rats can serve as a reinforcement in a T maze learning, whether it induces the activation of the alimentary drive or not. It follows that the main role of noradrenaline in this brain area consists not so much in induction of the alimentary drive as in activation of the very process which is essential for the reinforcement. It is claimed that intrahypothalamic microinjections of noradrenaline evoke pleasurable states which constitute a virtual reinforcement of motivated behavior.