Fig. 6.     Collection of high magnification color photomicrographs illustrate relationships between cholinergic neurons and TH-positive (A,B) or DBH-positive (C,D) fibers in the globus pallidus (A) and substantia innominata (B-D).  A:  A TH positive axon (arrowheads) with several varicosities (arrow)approaching a cholinergic neuron.  B:  A cholinergic neuron is apposed by several varicosities from type 3 and 4 TH-positive fibers. Arrowheads point to fine caliber axons. Small arrows denote smaller varicosities, the large arrow indicates two larger varicosities.  C:  DBH-positive varicosities (arrows) around a distal cholinergic dendrite. This neuron was photographed from a plastic embedded section processed for electron microscopy (see Figs. 8,9).  D:   Distal dendrites of cholinergic neurons in the lateral part of the substantia innominata apparently innervated by DBH-positive varicosities (some of which are indicated by arrows) from type 3 fiber. Arrowhead denotes axon. Photomicrographs in B-D were taken from sections using DAB/NiDAB method; A is from a section processed with the DAB/BDHC technique. Scale bar = 10 µm (applies to A-D).