Medycyna Wet. 65 (7), 498-502, 2009

full text

Lonc G., Krakowska I.
Structures and topography of the amygdala of the female chinchilla.
The aim of this study was to describe the structures and topography of the nuclei of the amygdaloid complex in chinchillas. The material for the study consisted of five chinchilla brains. The brains were fixed in formalin, dehydrated in ethyl alcohol and embedded in paraffin blocks. Next, the blocks were cut in the transversal plane into 12 µm-thick slices. The slices were coloured according to Klüver and Barrer’s method and examined under a light microscope (OLYMPUS BX 40) equipped with the camera Color View IIIu Soft Imaging System. For the morphometric measurements, the program Cell^D Soft Imaging System (SIS) was used. One can distinguish three parts of the amygdala: corticomedial amygdaloid complex (CMC), basolateral complex (BLC) and other amygdaloid areas.( OA). The BLC is divided into three nuclei: lateral amygdaloid nucleus (LA), basolateral amygdaloid nucleus (BL) and basomedial amygdaloid nucleus (BM). The chinchilla’s lateral amygdale (LA) is well developed and situated above the BL; laterally, it is bordered by the external capsule; the caudal pole of this nucleus constitutes at the same time the caudal pole of the amygdaloid complex. The basolateral amygdaloid nucleus in chinchillas is situated between the LA and BM. The basomedial amygdaloid nucleus is located ventromedially to the BM and dorsally to the cortical nucleus (CO). The corticomedial amygdaloid complex consists of the following: cortical nucleus (CO), medial nucleus (Me), central nucleus (CE), amygdalohippocampal area (AHA), the nucleus of the lateral olfactory tract (NLOT) and bed nucleus of the olfactory tract (BOAT). The nucleus of the lateral olfactory tract in chinchillas begins at the rostral part of the amygdala. It is bordered medially and dorsally by the anterior amygdaloid area (AAA) and laterally by the anterior part of the cortical nucleus. The chinchilla’s bed nucleus of the olfactory tract is situated behind the NLOT. Dorsally, it borders on the ME, laterally on the CO. The central nucleus constitutes the dorsomedial part of the amygdala. The amygdalohippocampal area in chinchillas is located in the caudal part of the amygdala between the inferior horn of the lateral ventricle and CO. The chinchilla’s cortical nucleus is a long band of neurons which constitutes the ventral part of the amygdala. The other amygdaloid areas include the anterior amygdaloid area (AAA) and intercalated nucleus (I) The intercalated nucleus consists of the group of neurons between the amygdala nuclei. The AAA constitutes the anterior pole of the chinchilla’s amygdala.
Keywords: amygdala, chinchilla, morphology,