Amygdaloid projections to the motor, premotor and prefrontal areas of the cat's cerebral cortex: a topographical study using retrograde transport of horseradish peroxidase.

The topographic organization of the projections from the amygdaloid complex to the frontal (motor, premotor and prefrontal) cortex has been investigated in the cat by means of the horseradish peroxidase retrograde transport technique. While most of these projections arise from the magnocellular component of the basal nucleus, some arise also from other nuclei, such as the parvocellular basal nucleus, the corticoamygdaloid transition area and the cortical nucleus. The projections from the latter nuclei are directed to the central portions of the prefrontal cortex, both laterally and medially. No clear-cut topographic segregation appeared to exist in the distribution within the magnocellular basal nucleus of the cells of origin of projections to the motor, premotor and prefrontal cortex. The gross topographic arrangement of the amygdalocortical projections seems to reciprocate, to some extent at least, the organization of corticoamygdaloid projections from high-order sensory and polymodal association areas.