THE PROTEOGLYCAN DSD-1-PG OCCURS IN PERINEURONAL NETS AROUND PARVALBUMIN-IMMUNOREACTIVE INTERNEURONS OF THE RAT CEREBRAL-CORTEX

Proteoglycans involved in the shaping of the developing brain are ofte n preserved in the adult brain in more restricted locations. We have s tudied the fate of DSD-1-PG, a chondroitin sulfate proteoglycan contai ning the hybrid epitope DSD-1. DSD-1-PG exerts neurite outgrowth promo ting activity and has been shown to occur in the developing brain duri ng late brain development and into adulthood. In the adult rat brain, monoclonal and polyclonal antibodies against DSD-1-PG labelled only th e circumference of a selected subpopulation of neurons. These nerve ce lls invariably expressed the calcium-binding protein parvalbumin. The label occupied the extracellular space in close vicinity to the cell b ody, surrounding axon terminals and glial end feet, but was absent fro m synaptic clefts. DSD-1-PG is thus shown to be an additional represen tative of the growing list of substances found in perineuronal locatio ns in the adult mammalian brain. Copyright (C) 1996 ISDN.