Figure 8. Basal forebrain at the level of the anterior commissure.

In this area containing the nucleus accumbens, the “classical” and “alternative” pathway enzymes Arg/SpdS (A, C) and ADC/Agm (B, D), respectively, clearly differed with respect to the homogeneity of labelling in the neuropil. With anti-Arg and anti-SpdS antibodies, patches of varying labelling intensity became evident in the Acb (arrowheads in A; double arrowheads in C) and striatum (asterisks in A, C). By contrast, ADC- and Agm-like immunoreactivity was comparatively homogeneous in these neuropil regions, most obviously displaying neuronal cell bodies. However, in the dorsal accumbens shell area, Agm labelling was pronounced in the neuropil (asterisk in D) and surrounded by stronger staining for Arg- and SpdS-like immunoreactivities. Note the prominent ADC-like immunoreactivity in the neighbouring major island of Calleja (arrow in B) resulting from the high density of labelled cell bodies in this area. LV = lateral ventricle ac = anterior commissure. Scale bar represents 400 µm.