“…In ferrets, a species like sheep in that a sexually dimorphic medial
preoptic nucleus develops prior to birth (Cherry,
Basham, Weaver, Krohmer, and Baum, 1990), Park et al (Park, Baum, Paredes, and Tobet, 1996;Park, Tobet, and Baum, 1998) found no sex difference in
neurogenesis, migration or cell death and concluded that the specification of a
distinctive neuronal phenotype i.e., soma size, area of dendritic fields or capacity
to produce a specific molecule may be responsible for establishing volumetric sex
differences in brain. The role of cell death and migration has also been challenged
by recent studies in mice (Gilmore, Varnum, and
Forger, 2012), which show that blocking bax-dependent developmental cell
death through targeted deletion of the bax gene does not prevent sex differences
from developing in the number of calbindin-immunoreactive neurons in the SDN.…”