Lesions of the posterior septum or of the habenula decrease [3H]hemicholinium-3 binding (as measured by autoradiography) in the interpeduncular nucleus of the rat.

The effects of a bilateral electrolytic lesion of the posterior septum or of the habenula (lateral and medial parts) on [3H]hemicholinium-3 binding sites in the interpeduncular nucleus of the rat were studied through the use of quantitative autoradiography. Lesions of the habenular nuclei or of the posterior septum decreased [3H]hemicholinium-3 binding in the interpeduncular nucleus by 93 and 31%, respectively. These results add further support to the view that the habenula and posterior septum are the major sources of the cholinergic innervation of the interpeduncular nucleus in the rat.