Mouse nestin protein localizes in growth cones of P19 neurons and cerebellar granule cells.

The neuronal growth cone, a highly motile structure at the distal tip of growing axons, contains filamentous actin and microtubules as its main cytoskeletal components. Using immunocytochemistry, we observed that nestin, which is the predominant intermediate filament protein in neuroepithelial cells and young neurons of the developing brain, appears to be strongly expressed in neurites and growth cones of neurons differentiating from P19 embryonic carcinoma cells in vitro. Double-staining of nestin and microtubule-associated protein-2 as well as nestin and growth-associated protein-43 revealed that nestin protein localizes in neurites and the central regions of growth cones of primary cultures of cerebellar granule cells from postnatal day 6 mice. These results suggest a role for nestin in growth cone guidance during axon elongation.