Long term potentiation of lateral hypothalamic self-stimulation following parabrachial lesions in the rat.

Two neural systems in the pontine tegmentum have been implicated in reward processes. One is the visceral afferent-column arising from the nucleus of the solitary tract and the pontine tegmental taste area (PTA), the other being the dorsal noradrenergic system that has its origin in the locus coeruleus (LC). Lesions of the LC had no effect on lateral hypothalamic (LH) intracranial self-stimulation (ICSS) whereas lesions of the PTA produce a dramatic and seemingly permanent increase in LH ICSS response rates. These results are discussed in the context of noradrenergic/dopaminergic interactions in the control of goal-directed behaviors.