Neonatal undernutrition and amygdaloid nuclear complex development: an experimental study in the rat.

This study describes the morphology of neurons from the basolateral (ABL), central (ACE), and medial (AM) nuclei of the amygdaloid complex in neonatally undernourished (U) and control (C) Wistar strain rats. The cells were impregnated with the Golgi-Cox technique and studied at the ages of 12, 20, and 40 days postnatally. In the U-pups the neurons of the three nuclei displayed a reduced somatic area compared to that of the C-group on Days 12 and 20. However, at 40 days, this difference diminished due to a reduction in the somatic area of the C-group. The dendritic area also appeared reduced on Days 12 and 20 in the U-group, but on Day 40 it reached control values. The neurons from ABL and ACE suffered a significant decrease in the number of dendritic branches due to undernutrition, but the AM nucleus did not show this change. The data suggest different vulnerability of these amygdaloid nuclei to neonatal undernutrition. The findings also suggest that the abnormal emotional response characteristic of perinatal undernourished rats could have a morphological cause.