Role of Pten in Neuron Morphology and Connectivity

PTEN is essential for both, central nervous system (CNS) development and maintenance of CNS circuit structure and func-tion. The generation of conditional mutant animals has allowed exquisite control over temporal and spatial patterns of Pten expres-sion and delineated specific roles for Pten at each developmen-tal stage. During early embryonic development, Pten deletion in proliferating neural stem/progenitor cells results in increased cell proliferation, and severe defects in cortical, hippocampal and cer-ebellar lamination.10,11 Pten also inhibits cell proliferation of adult born neural stem cells, controlling self-renewal in the olfactory bulb12 and dentate gyrus.13 After neurons become post-mitotic, Pten deletion or knock-down has dramatic effects on neuro-nal growth, highlighting the importance of Pten for controlling post-mitotic neuronal development.14,15 Deletion of Pten in dif-ferentiated postmitotic cortical and hippocampal neurons leads t