Functional evidence for a direct excitatory projection from the lateral habenula to the ventral tegmental area in the rat.

摘要: The lateral habenula, a phylogenetically conserved epithalamic structure, is activated by aversive stimuli and reward omission. Excitatory efferents from the habenula predominately inhibit midbrain dopamine neuronal firing through disynaptic, feedforward inhibitory mechanism involving rostromedial tegmental nucleus. However, also directly targets neurons within ventral area, suggesting that opposing actions may result increased activity. In present study, we tested effect of habenular efferent stimulation on nondopamine in area Sprague-Dawley rats using parasagittal brain slice preparation. Single pulse fasciculus retroflexus excited 48% 51% rat pups. These proportions were not altered excision nucleus evident both cortical- striatal-projecting neurons. Glutamate receptor antagonists blocked this excitation, elicited evoked excitatory postsynaptic potentials with nearly constant onset latency, indicative monosynaptic, glutamatergic connection. Comparison responses pups young adults showed no significant difference proportion stimulation. Our data indicate well-known, indirect activation complemented significant, direct effect. This pathway contribute to role processing salience.