In vivo studies of granule cell gene expression during corticocerebellar development and in vitro studies of Purkinje cell neurite outgrowth suggest that neurotrophin-3 may influence growth of Purkinje cell dendrites. To determine whether neurotrophic substances affect the growth of specific neuronal processes (i.e. axons and dendrites) or nonspecifically cause process development by exerting a trophic influence upon neuronal physiology we performed an immunohistochemical examination of trkC protein expression during early postnatal development of the rat cerebellum. Our findings indicate that Purkinje cells begin to synthesize trkC protein coincident with the onset of dendritic outgrowth. Robust immunostaining was evident throughout the entire somatodendritic domain of Purkinje cells during dendritic development but became faint and restricted to the cell body subsequent to the completion of dendritogenesis. These results suggest that growth and maturation of the Purkinje cell dendritic arbor may be influenced by neurotrophin-3 activation of trkC receptors distributed within developing dendrites.