Morphology, size and distribution of corticotropin releasing factor (CRF) immunoreactive neurons in the central nucleus of the rat amygdaloid complex

Abstract

The amygdaloid complex (AC) is a heterogenous group of cortical and nuclear structures. As an important component of the limbic system contains numerous neurotransmitters including neuropeptides. In this study we have investigated the types, distribution, and morphometric characteristics of corticotropin releasing factor (CRF) immunoreactive neurons in the central nucleus (Ce) of the AC. We have also identified CRF- immunoreactive fibers in this nucleus. This research was performed on 5 adult rats kept in standard conditions. Animals were perfused 48 hours after application of colhicin. The removed brains were postfixed and cut into free floating sections. The sections were treated with antibodies against the rabbit CRF and ABC immunohistochemstry was applied. The neurons were measured and drawn with a camera lucida. We found uniform distribution of CRF immunoreactive neurons in the Ce of AC of rat. According to morphological type dominant were triangular (50%), while bipolar (25%) and multipolar (25%) types were also present. The most of the CRF immunoreactive neurons had 2-5 primary dendrites. These findings will contribute to understanding the role of CRF neurons in rat Ce during stress and in other behavioral functions.