[Mechanisms for dendritic morphogenesis of cerebellar purkinje cells: role of receptor-type protein tyrosine phosphatase zeta].

Cerebellar Purkinje cells have the most elaborate dendritic trees among neurons in the central nervous system, which are formed into a characteristic morphology during postnatal cerebellar development. PTPzeta is a receptor-type protein tyrosine phosphatase that is expressed predominantly in the central nervous system and synthesized as a chondroitin sulfate proteoglycan. PTPzeta and pleiotrophin, a ligand of PTPzeta, are distributed around Purkinje cell dendrites during postnatal cerebellar development. Our study using an organotypic slice culture system demonstrated that pleiotrophin-PTPzeta signaling is involved in the morphogenesis of Purkinje cell dendrites. An aberrant morphology of Purkinje cell dendrites such as multiple and disoriented primary dendrites was induced by disturbing pleiotrophin-PTPzeta signaling in slice cultures. Pleiotrophin-PTPzeta signaling appears to act on Bergmann glia and control formation and/or maintenance of GLAST-positive lamellate processes of Bergmann glia, which regulate the morphogenesis of Purkinje cell dendrites.