Alternate coexistence of NADPH-diaphorase with choline acetyltransferase or somatostatin in the rat neostriatum and basal forebrain.

The coexistence of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) with somatostatin (SOM) and choline acetyltransferase (ChAT) was compared between the rat neostriatum (ST) and basal forebrain complex (BF) . NADPH-d coexists with SOM in ST, but not in the ventral pallidum (VP), in the substantia innominata-nucleus basalis complex (SI-NB) and in the magnocellular preoptic nucleus (NPM) of the BF. In the medial septal nucleus as well as in the vertical and the horizontal limbs of the diagonal band (MS-vDB, hDB) representing the rostral BF and in the SI-NB, a high number of ChAT-positive cells also contain NADPH-d. The NPM shows a smaller number of double-stained cholinergic neurons. The functional significance of the NADPH-d coexistence in BF cholinergic cells is still unknown.