Topographical projections from the nucleus basalis magnocellularis (Meynert) to the frontal cortex: A voltage-sensitive dye imaging study in rats

•Topographical mapping between the nucleus basalis magnocellularis/Meynert (NBM) and frontal cortex was examined.•Anterior and posterior NBM was stimulated and frontal activity was visualized using optical imaging.•The anteroposterior axis of the NBM corresponded to the mediolateral axis of the dorsal frontal cortex.

BackgroundThe nucleus basalis magnocellularis/Meynert (NBM) has been explored as a new target for deep brain stimulation for neurological disorders. Although anatomical studies suggest the existence of cholinergic topographical projections of the NBM, it is still unknown whether NBM subregions differentially activate the frontal cortex.ObjectiveTo investigate the topography between the NBM and frontal cortex.MethodsElectrical stimulation was applied to the anterior and posterior sites of the NBM in rats, and the evoked frontal activity was investigated using voltage-sensitive dye (VSD) imaging.ResultsVSD imaging revealed the functional topography of the NBM and frontal cortex: the anteroposterior axis of the NBM corresponded to the mediolateral axis of the dorsal frontal cortex.ConclusionThe present results suggest site-specific control of frontal neuronal activity by the NBM. These findings have practical implications, as the anterior and posterior parts of the NBM could be targeted to improve cognitive and motor function, respectively.