Fig. 10.
A: PHA-L injection site in the dorsal
raphe nucleus. The same section stained for serotonin (5-HT) (A') reveals that
many of the labeled neurons contain serotonin. B: A cholinergic neuron
from the dorsal aspect of the HDB (arrow in D) is approached by PHA-L fibers
with varicosities. C: Serotonin axon with varicosities in juxtaposition
to cholinergic neurons in the same area of intact animal. Note the similar
pattern of axonal arborization with respect to cholinergic neurons in B and C.
Scale; A, A', and D = 100µm; B and C = 10µm. Abbrev. ac = anterior
commissure; Aq = aqueductus cerebri; FStr = fundus striati; mlf = medial longitudinal
fascicle.