CHOLINERGIC NEURONS FROM DIFFERENT SUBDIVISIONS OF THE BASAL FOREBRAIN LACK CONNECTIONAL SPECIFICITY FOR CEREBRAL CORTICAL TARGET SITES IN-VITRO

Basal forebrain cholinergic neurons send their axons to cerebral corte x in a topographically organized projection. Experiments tested the hy pothesis that this topographic organization results from target prefer ences of the cholinergic neurons. Slices containing either medial sept um or substantia innominata were grown in co-culture with slices of la teral neocortex and hippocampus. Cholinergic neurons from septum and f rom substantia innominata projected axons into neocortex and hippocamp us, without obvious differences in pattern or density. These data sugg est that basal forebrain cholinergic neurons can innervate any portion of the cerebral mantle.