Photomicrographs of ChAT-ir profiles in the mesencephalon. Coronal section
showing ChAT-ir neurons within the Edinger-Westphal (EW) and oculomotor nuclei
and third cranial nerve rootlets (black arrows) (A). Low-power
photomicrograph of a horizontal section showing the Edinger-Westphal, third
(IIIn) and fourth (IVn) cranial nerve nuclei (B). Horizontal
section showing swirling ChAT-ir fibers in the central portion of the
interpeduncular nucleus (IP, C). Low-power photomicrograph
(D) of ChAT-ir fibers within the superficial laminae of the
superior colliculus. Scale: 250 μm A; 1000 μm B; 500 μm
C, D. Anatomic orientation: R= rostral, C= caudal, L=
lateral, M= medial.