Microanatomy of the cerebellum in Persian squirrel (Sciurus anomalus), a transmission electron microscopy, and immunohistochemical study.

The present study was aimed to investigate the cerebellum histology in the Persian squirrel (Sciurus anomalus), using immunohistochemical staining and transmission electron microscopy (TEM). The brain of 4 adult Persian squirrels (2 males and 2 females) were used. For general histology, crystal violet and Luxol fast blue stains were applied. For immunohistochemical examination, myelin associated glycoprotein (MAG), neurofilament 200 (NF200), Calbindin D 28 K, and glial fibrillary associated protein (GFAP) were investigated. The cerebellar cortex was composed of three traditional cellular layers, including molecular, granular and Purkinje cell (Pc) layers. Numerous Nissl bodies detected in the cytoplasm of Pc, which given a purple or blue appearance to the cytoplasm. At the level of TEM, Purkinje cells were identified by their large euchromatin nucleus with an indented plasma membrane. The cytoplasm was high electron dense containing well-developed rough endoplasmic reticulum (Er), smooth Er, Golgi apparatus in perinuclear region, numerous mitochondria in oval and spherical shapes, free ribosomes, and lysosomes were dispersed throughout the cytoplasm. The expression rate of calbindin D 28 K, MAG, GFAP, and NF200 was determined 49%, 24%, 71%, and 43% respectively. The cerebellum of the Persian squirrel has a common structure similar to those reported in other mammals. However, at the level of TEM, some unique structural features were observed. These results might be taken as a set of basic information for more detailed future studies investigating histophysiology of the cerebellum and its pathological changes in the Persian squirrel as well as for comparative purposes in rodent species.