a considerable number of ia cells ( 13,600 , representing 23 % of the total ) were found in locations outside the raphe nuclei : in ventral brainstem as lateral extensions from the raphe , among the bundles of fasciculus longitudinalis medialis , in periventricular gray and adjacent tegmentum , mixing with the noradrenergic cells of the locus coeruleus complex , among the mesencephalic dopamine cells , and in the nucleus interpeduncularis .
C0006121
brainstem
C0025462
mesencephalic