Fig. 11.     A: PHA-L injection site in the ventral medullary reticular formation. B: Enlarged view of the upper part of the box of A showing several PHA-L labeled neurons. Arrow points to a neuron which is double-labeled for dopamine-ß-hydroxylase (DBH). C: The same section as in B stained for DBH. A number of noradrenergic cells of the A1 group are visible in the lower half of the picture. D: Combined PHA-L/ChAT staining from the same case showing the distribution of PHA-L labeled fibers in the forebrain in relation to cholinergic neurons. Bar Scale; A = 500µm; C = 100µm. Star indicates the same vessel in B and C. Abbrev. f = fornix; GP = globus pallidus.