Stellate cells differentiate successively in the cat sensorimotor cortex during early postnatal ontogeny

Golgi and Golgi-Kopsch techniques were used to investigate maturation of stellate and pyramidal cells and development of stellate-pyramidal connections in kittens of the following ages: 2, 7, 14, 21, 28 and 34 days. By two weeks, stellate cells in layer V have become mature. Layer III stellate cells with vertical axon ramifications are differentiated by 2-3 weeks of life and in 3-week-olds the horizontal spread of axon collaterals amounts to 1300 micrometer. Layer II stellate cells which are poorly developed n newborns acquire the greatest number of collaterals and a complex axon branching pattern by 4 weeks of age.