NERVE GROWTH-FACTOR STIMULATES GROWTH OF CORTICAL PYRAMIDAL NEURONS IN YOUNG-ADULT RATS

The cytoarchitectonics of pyramidal neurons in the cerebral cortex of non-lesioned rats can be re-modeled by i.c.v. infusions of nerve growt h factor (NGF). 4 months after the application of NGF, the pyramidal n eurons in layers III and V of the motor cortex and layer V of the ante rior cingulate cortex were analyzed and compared with pyramidal neuron s from vehicle-treated rats. NGF-treated brains showed: (1) significan t increase in dendritic branching in the basilar fields of the layer V , but not layer III, neurons; and (2) a significant increase in spine density in the terminal, but not proximal, dendritic branches. These f indings indicated that, besides its known effects on forebrain choline rgic neurons, NGF produces a very generalized synaptic re-modeling inv olving the cells responsible for the major output of the cerebral cort ex in the intact adult brain. (C) 1997 Elsevier Science B.V.