Connection between the prefrontal cortex and pontine brain-stimulation reward sites in the rat

Abstract

Electrical stimulation of sites in the pontine tegmentum near the locus ceruleus excited some neurons in the prefrontal cortex antidromically, and activated other nearby neurons transsynaptically. The prefrontal neurons were activated by the pontine stimulation at current intensities lower than those which had previously provided brain-stimulation reward. A comparable strong activation of neurons was not found in other neocortical areas. It is concluded that because neurons in the sulcal and medial prefrontal cortex are activated by rewarding stimulation of the far-distant pontine tegmentum, as well as of other reward sites, activation of the demonstrated pathway between the prefrontal cortex and the pontine tegmentum may be involved in brain-stimulation reward. In addition it is concluded that self-stimulation of the region of the locus ceruleus does not necessarily depend on the activation of the noradrenaline-containing neurons of the locus ceruleus.