Cholinergic tone in ventral tegmental area: Functional organization and behavioral implications

The ventral tegmental area (VTA), a pivotal brain region of the mesocorticolimbic dopaminergic system, is substantially innervated and modulated by cholinergic projections from the pedunculopontine tegmental nucleus and laterodorsal tegmental nucleus. In this review, we focus mainly on the current findings on VTA cholinergic compositions and functions, including VTA cholinergic innervations and synaptic connectivity, acetylcholine receptor expression and functional characteristics, cholinergic modulation of neuronal activity and dopamine efflux, cholinergic modulation of VTA-mediated behaviors such as reward and addiction, stress and depression, locomotion, etc. Taken together, these findings indicate that cholinergic transmission to the VTA plays an important role in modulation of the VTA circuit, which is implicated in regulation of multiple behaviors.