The first mammalian Wnt to be discovered,
Wnt-1, was found to be essential for the development of a
large part of the mouse brain over 25 years ago. We have
since learned that Wnt family secreted glycolipoproteins,
of which there are nineteen, which activate a diverse network
of signals that are particularly important during
embryonic development and tissue regeneration. Wnt signals
in the developing and adult brain can drive neural stem
cell self-renewal, expansion, asymmetric cell division,
maturation and differentiation. The molecular events taking
place after a Wnt binds to its cell-surface receptors are
complex and, at times, controversial. A deeper understanding
of these events is anticipated to lead to improvements in
the treatment of neurodegenerative diseases and stem cellbased
replacement therapies. Here, we review the roles
played by Wnts in neural stem cells in the developing
mouse brain, at neurogenic sites of the adult mouse and in
neural stem cell culture models.