cell death and sexual differentiation
in mice and rats.
large number of sex differences have
been described in the nervous systems
of mammals. In most cases, sex differences
in neural structure or neurochemistry
can be traced to the actions of the
steroid hormone, testosterone, produced
by the testes of perinatal males.
For example, testosterone creates
sex differences in neuron number by
controlling developmental cell death.
Throughout the nervous system, many
more neurons are born than will survive
into adulthood, and “excess”
neurons die during a period of naturally
occurring cell death. Testosterone
(or one of its hormonal metabolites)
decreases neuronal cell death in some
areas of the brain and spinal cord,
while increasing cell death in others.
We are investigating the cell and
molecular mechanisms underlying these
actions of testosterone. Specifically,
we have been focusing on neurotrophic
factors, and proteins of the Bcl-2
family as likely mediators of hormonally-controlled
cell death. (For more information,
et al., 2001,
et al., 2004 and Jacob
et al., 2005.)