Cytoarchitecture and acetylcholinesterase activity of the amygdaloid nuclei in the dog.

The cellular structure and distribution of histochemically demonstrated acetylcholinesterase (AChE) activity were studied in the amygdaloid body of 9 dogs. Cytoarchitectonic observations were made in series of paraffin and celloidin sections stained with cresyl violet. For the demonstration of the acetylcholinesterase activity, modifications of Koelle method were used. The general pattern of morphological structure of the dog's amygdaloid body is similar to that in other mammalian species. The corticomedial group of the nuclei was characterized generally by cytoarchitectonic uniformity of small, lightly stained cells and low intensity of the AChE reaction, except for the nucleus of the lateral olfactory tract and the lateral part of the central nucleus. The latter showed further differentiation in both cellular arrangement and distribution of AChE activity and may be divided into three subdivisions. The basolateral group of nuclei was characterized by higher differentiation of the cellular arrangement and distribution of the AChE activity. The highest enzyme activity was observed in the basal magnocellular nucleus. These findings support the homology of particular amygdaloid nuclei in various mammalian species.