Cholinergic nucleus basalis neurons may influence the cortex via the thalamus

The cholinergic neurons of the nucleus basalis of Meynert have been shown to provide the major cholinergic innervation of the cerebral cortex through which cholinergic transmission may modulate cortical activity. This study describes a projection from the cholinergic and non-cholinergic neurons of the nucleus basalis to the reticular nucleus of the thalamus, and a projection from the brainstem cholinergic neurons to the reticular nucleus as well as to other thalamic nuclei. The projection from the nucleus basalis to the reticular nucleus, which itself is synaptically interconnected with other thalamic nuclei, may provide an additional pathway for the modulation of cortical activity by the cholinergic basal forebrain and brainstem groups.