Efferent connections of the basolateral amygdaloid part to the archi-, paleo-, and neocortex in dogs

Abstract

Small electrolytic lesions were placed in the basal and lateral amygdaloid nuclei of the dog and the distribution of degenerating fibers was studied with Nauta and Fink-Heimer modifications of the impregnation methods. Degenerating axons were followed into the hippocampal region and entorhinal cortex as well as insular and temporal cortices. The present results suggest that: (i) The hippocampal region receives projections from the basal parvocellular and basal magnocellular nuclei; (ii) the entorhinal cortex from the lateral and basal parvocellular nuclei; (iii) the insular cortex, cortex of the anterior ectosylvian and sylvian gyri, and to a smaller degree the claustrum, from the lateral and basal magnocellular nuclei; (iv) the temporal cortex of the posterior suprasylvian gyrus from all nuclei of the basolateral part of the amygdala. It is concluded that the basolateral part of the amygdala in the dog has a complex and highly developed connections with the archi-, paleo- and neocortex.