Vimentin-immunoreactivity in the developing striatum of the rat

Postnatal development of vimentin positive and glial fibrillary acidic protein (GFAP) positive elements in the striatum of the rat was analyzed by immunohistochemistry. Regional and chronological differences in the transformation of vimentin-positive radial glial cells were observed in the dorsal and ventral striatum. In the dorsal striatum, unwinding of the fasciculus of vimentin-positive fine fibers from the periphery toward the more central region of the striatum was observed from postnatal day (P) 3 to P7. In the ventral striatum, however, a fragmented transformation characterized by the segmental disappearance of vimentin-positive radial glial fibers was observed from P3 to P14. On the other hand, GFAP-positive astroglial cells were observed first in the dorsocaudal part of the striatum near the corpus callosum at PO. Numbers of GFAP-positive astroglial cells increased with age, and distribution of these cells extended toward the medial region of the striatum. At P14, these GFAP-positive cells were distributed throughout the striatum, including the dorsal and ventral striatum. These findings indicate that differences in transformation of radial glial cells in the ventral and dorsal striatum may be attributed to differences in neurogenesis and formation of neuronal circuits in the dorsal and ventral striatum. These results provide new insight into the role of radial glial cells in the developing striatum.