Mice lacking NT-3, and its receptor TrkC, exhibit profound deficiencies inCNS glial cells

Neurotrophin-3 (NT-3) and its receptor TrkC are known to be important for n euronal survival. More recently, NT-3 has been implicated as playing a role in oligodendrocyte (OL) proliferation and survival in vitro. Examination o f NT-3 and TrkC knockout mice revealed a reduction in NT-3-dependent neuron s. To date, no study has examined alterations in glial cell populations in these knockout mice. In this report, we demonstrate a decline in OL progeni tor cell numbers within the CNS of NT-3 and TrkC knockout mice. We also obs erved that immature and mature OL-specific markers were attenuated in the N T-3 and TrkC knockout animals. Deficiencies in other CNS glial cells, inclu ding astrocytes and ameboid microglia, were also observed. The subventricul ar zone (SVZ), a highly proliferative region for progenitor glial cells, wa s reduced in size. Furthermore, a nuclear-specific stain revealed a decline in the numbers of pyknotic nuclei in and around the SVZ of the knockout mi ce. These data will support an in vivo NT-3-dependent mechanism for the nor mal development of CNS glial cells. GLIA 26:153-165, 1999. (C) 1999 Wiley-L iss, Inc.