[Identification of nerve cells in the visual cortex of the rat using Nissl and Golgi-Kopsch methods]

The neurons of the visual cortex of the albino rat were studied using both the Nissl- and Golgi-Kopsch methods. In Nissl preparations we can distinguish between a group of neurons rich in cytoplasm, a group of neurons poor in cytoplasm and an intermediate group. In the Golgi preparations the neurons can be subdivided according to the shape of their cell bodies, dendrites and axons. Spiny cells with long axonal main trunks are pyramidal cells, multiangular cells and stellate cells of layer IV. Cells with spineless dendrites and short axonal arborization are basket cells, neuroglioform cells and small double bouquet cells. Due to its spines and the short axonal arborization, the coarse fusiform cell (Martinotti cell) is an intermediate type. We assume cells having long axons and dendritic spines are category I neurons and cells having short axons and no or a few spines are category II neurons (according to SZENTAGOTHAI 1973). On the basis of homological criterions and taxonomically relevant features references for identifying the cell group rich in cytoplasm and category I neurons, on the one hand, and the cell group poor in cytoplasm and category II neurons, on the other hand, were found. The group of cells rich in cytoplasm is related to pyramidal cells, multiangular cells and stellate cells of lamina IV. The group of cells poor in cytoplasm is discussed as corresponding to cells of lamina I, round or oval forms as basket cells and neuroglioform cells, fusiform cells as double bouquet cells. The intermediate cell form in the Nissl preparations is according to the Martinotti cell in Golgi material. These findings allow quantitative studies about particular cell populations and can, completed with electron microscopical date, instruct computer models to simulate the complicate neuronal network of the visual cortex.