Developmental changes of morphology in the basolateral complex of the rabbit amygdala.

The aim of the present study is to follow topographical and morphological changes in the development of the amygdaloid basolateral complex (BLC) in the rabbit. The material consists of 35 brains of New Zealand rabbits of both sexes, divided into 7 age groups (P2-P90). In cresyl violet preparations BLC is already well visible on P2 and is composed of the lateral (divided into dorsolateral and ventromedial divisions), basolateral and homogenous basomedial nuclei. On about the 7th postnatal day it is possible to divide the basomedial nucleus (BM) into dorsal (Bmd) and ventral (BMv) divisions. The topography and subdivisions set on P7 are maintained in further periods of life. The morphology of neurons (shape, dendrites, staining) changes significantly until P21 in all BLC nuclei. Our results indicate that BLC achieves morphological maturity relatively late, which is probably connected with a long creation of emotional memory and regulation of emotional behaviour.