BRAIN-DEVELOPMENT AND MULTIPLE MOLECULAR-SPECIES OF PROTEOGLYCAN

The occurrence of multiple proteoglycan species is a characteristic of the brain. The structural features of individually characterized prot eoglycans in the brain are first introduced in brief, then some exampl es are shown that suggest a relationship between multiple proteoglycan s and the many distinct cell types and neural circuits in the brain. T ypical experiments demonstrated the neuronal-activity-dependent expres sion of neural proteoglycans during the critical developmental period of some functional systems such as the visual and vibrissal barrel sys tems. In addition, the binding properties of neural proteoglycans to o ther cell surface molecules are discussed in conjunction with their in volvement in cell-cell and cell-substratum interactions. This review a lso covers other potential functions of proteoglycans not only in the development and maintenance of the brain but also in the pathogenesis of Alzheimer's disease. Proteoglycans are really coming of age in neur oscience.