Fig. 4.     A: Camera lucida drawing (10x) from a double-labeled section illustrating the distribution of PHA-L labeled fibers in relation to cholinergic neurons following delivery of the tracer to the orbitofrontal cortex. B: Schematic drawing (from section adjacent to the one shown in A) illustrating the distribution pattern of PHA-L labeled terminals in apposition to cholinergic neurons from a section that was analyzed using high magnification light microscopy. Cholinergic neurons are represented by dots. Zones of putative contacts between PHA-L-positive terminals and cholinergic profiles are depicted as squares. Sections were screened using an ocular reticle (80x80 µm) at 63x, and contact sites were marked on a camera lucida drawing of the corresponding section using a proportional grid. Abbrev. ac = anterior commissure; Acb = accumbens nucleus; BL = basolateral amygdaloid nucleus; BSt = bed nucleus of the stria terminalis; CA = central amygdaloid nucleus; CP = caudate putamen; DM = dorsomedial hypothalamic nucleus; f = fornix; GP = globus pallidus; HDB = horizontal limb of the diagonal band; ic = internal capsule; LSd = lateral septal nucleus, dorsal; LSi = lateral septal nucleus, intermediate; LV = lateral ven-tricle; MCP = magnocellular preoptic nucleus; MS = medial septal nucleus; ot = optic tract; Rt = reticular thalamic nucleus; SI = sublenticular substantia innominata; sm = stria medullaris; VDB = vertical limb diagonal band nucleus; VM = ventromedial hypothalalamic nucleus; VP = ventral pallidum.