Calbindin Immunoreactivity in Rat Cerebral Cortex and Cerebellum Neurons

Objective. To carry out an immunohistochemical assessment of the distribution of calbindin D28K in cerebral cortex (parietal and frontal) and cerebellum neurons in rats.Materials and methods. Experiments were performed on 18 mongrel white male rats weighing 200–250 g. Fragments of the frontal and parietal cortex and cerebellar cortex were collected. Paraffi n sections were processed using primary polyclonal antibodies to detect calbindin D28K immunoreactivity.Results. In layer II of the frontal and parietal cortex, most neurons were moderately immunopositive, while layers III, V, and VI contained occasional neurons with high calbindin immunoreactivity. Individual nerve fibers, mainly the dendrites of pyramidal neurons, were clearly seen. Some of these showed a distinctive staining pattern: immunopositive parts alternated with immunonegative parts. In the cerebellar cortex, the bodies and dendritic branches of Purkinje cells were well stained. A significant proportion of neurons in the granular layer were moderately immunopositive, and included some afferent nerve fibers running from the white matter.Conclusions. Calbindin immunoreactivity in cerebral cortex structures in normal rats varied significantly and could be related both to the type of neuron and their functional state.