Mesoamygdaloid dopamine neurons: differential rates of dopamine turnover in discrete amygdaloid nuclei of the rat brain.

Populations of dopamine (DA) neurons innervating discrete amygdaloid nuclei exhibited a widely varying rate of biochemically estimated tonic activity, with DA turnover rates in the various amygdaloid nuclei increasing in the following order: central, medial posterior, medial, posterior, basal, basal posterior, cortical, lateral amygdaloid nucleus. With the exception of the central and the medially aligned amygdaloid nuclei, mesoamydaloid DA neurons exhibited a faster rate of DA turnover than the well-characterized DA neurons projecting to the caudate nucleus and olfactory tubercle. When amenable to estimation by this technique, the activity of mesoamygdaloid norepinephrine (NE)-containing neurons was less than that of mesoamygdaloid DA neurons. These findings support the focal influence of DA in the amygdaloid complex and reinforce the biochemical and functional heterogeneity of the component nuclei of the amygdala.