CELLS ON THE EDGE - BOUNDARY ASTROCYTES AND NEURONS

The caudate-putamen nucleus (neostriatum) is organized as a mosaic of two compartments that during development are cordoned off by astrocyte s and associated glycoconjugates. There are complex interactions betwe en these boundary astrocytes and neurons during pattern formation in t he neostriatal mosaic, with distinct classes of neurons (such as NADPH -d/NOS cells) residing within boundary as well as nonboundary sites. A n hypothesis is presented that implicates glial cells, different class es of neurons, synaptic activity, and neurotoxicity in the shaping of normal cytoarchitectonic and connectional arrangements in the neostria tum. Within such a scenario, special glial cells and neurons are on th e edge between compartments, living and dying.