Evidence that efferents from the basolateral amygdala innervate the dorsolateral neostriatum in rats.

The dorsolateral precommissural caudate-putamen complex has been characterized recently as a 'non-limbic' region of the neostriatum. In the present study, however, it was found that numerous neurons in the basolateral amygdala were labeled retrogradely following infusions of Evans Blue into that neostriatal region. Control infusions demonstrated that such labeling could not be attributed to the spread of the red fluorescent tracer into surrounding neocortical areas. On the basis of these data, it is proposed that: (1) the amygdalo-neostriatal pathway may be more extensive than previously believed, and (2) the basolateral amygdala may serve as an important link between the limbic and extrapyramidal motor systems.