Fig. 23.     B: High power light micrograph shows a ChAT-positive neuron (from region denoted by asterisk in A) which is approached by a PHA-L labeled fiber bearing several terminal varicosities, one of which is seen in apposition to the soma (arrow). The PHA-L injection site was located in the medial preoptic area (case M 078). C: Low power electron micrograph showing the ChAT-positive cell body. Boxed area contains the PHA-L varicosity indicated by arrow in (B). Arrowhead denotes the other PHA-L labeled terminal shown with the same symbol in (B), which contacts an unlabeled dendrite. D: High power electron micrograph from boxed region in (C). Symmetric contact between PHA-L labeled terminal and ChAT-positive cell is denoted by arrowheads. Scale bar: 1 µm.