[Age related classification of neurons in the rat visual cortex: a Nissl study (author's transl)].

Using Nissl preparations, 6, 8, 12, 16, 20, 30, 90, and 420 days old albino rats were investigated with regard to classification of several neuron types within layer IV and adjacent zones of layers III and V. Increasing maturation of the nervous tissue provides a greater classifiable variety of neuron types. About between the second and third postnatal week the degree of classification reach partially almost the same level as in the adult animals. Particular attention is paid to a large, frequently bipolar neuron type rich in cytoplasm.