Fig. 9. Correlated light
and electron microscopy of an axosomatic contact between a PHA-L-labeled bouton
emanating from the medial SNC and a cholinergic cell in the VP (case 93048). A:
Location of the cell indicated by the star in boxed area, which is shown in B.
B: Low-power micrograph of section showing ChAT-positive neurons and plexus of
PHA-L-labeled fibers (far left, arrows). The recipient neuron is in boxed area. Dark
area on the top left is anterior commissure. B': Enlargement of boxed area in B
containing the recipient ChAT-positive neuron. C: Low-resolution electron
micrograph of the ChAT-positive cell body and PHA-L-filled terminal
establishing a synapse. C': The terminal abutting the cell (arrow).
D: High power of a symmetrical synaptic contact (open arrows) between the
afferent fiber (heavily electron dense) and the cholinergic cell. Presynaptic
vesicles and mitochondria are electron lucent. Note the flocculent DAB
precipitate along the postsynaptic membrane and on the rough endoplasmic
reticulum. The PHA-L-positive bouton is neighbored by an unlabeled terminal
(asterisk), which shows a small area of asymmetrical synaptic specialization
(shown in D', adjacent ultrathin section). Scale bars = 200 µm in B, 50 µm inB',
2 µm in C, 10 µm in C', 0.5 µm in D,D'.