Localization of calcium-binding protein parvalbumin-immunoreactive neurons in mouse and hamster visual cortex

Calcium-binding proteins are thought to play important roles in regulating intracellular calcium in the central nervous system. In the present study, we investigated the distribution and morphology of neurons containing parvalbumin in the visual cortex of mouse and hamster. The calcium-binding proteins were localized using immunocytochemistry. Parvalbumin-immunoreactive neurons were located in all layers except layer I. The highest density of parvalbumin immunoreactivity was found in layer V of both mouse and hamster. The labeled neurons varied in morphology. The majority of the parvalbumin-immunoreactive neurons both in mouse and hamster visual cortex was stellate and round, or oval with multipolar dendrites. These results indicate that the calcium-binding protein parvalbumin is contained in specific layers and in selective cell types of the mouse and hamster visual cortex. The distribution of parvalbumin in the mouse visual cortex is very similar to that of hamster.