Developmental aspects of the neocortex of the bat

Golgi studies on the cerebral cortex (central region) of newborn and adult bats (Myotis myotis) have shown that (a) extraverted cells in layer II-III are the source of a rich horizontal plexus originating from large numbers of long, proximal axonic collaterals, and (b) significantly greater numbers of basilar and apical dendrites (Student's t-test, P less than 0.001) of extraverted pyramidal cells are found in the newborn than in the adult bat, indicating an overproduction of dendrites during the early stages of development.