Evidence for cholinergic muscarinic receptors on mediodorsal thalamic projections to the anterior cingulate cortex

Cholinergic muscarinic receptor binding was analyzed in the rat brain anterior cingulate cortex following lesions of the mediodorsal or anterior thalamic nuclei, or the diagonal band of Broca. A significant change in receptor binding was noted only after lesions of the mediodorsal projection, suggesting that cholinergic muscarinic receptors are located on these terminals. These findings suggest that the projection from the diagonal band of Broca which is cholinergic may act as a modulator of the mediodorsal thalamic projection.