Roslyn Holly Fitch (1995) Estrogen is Still Important. Psycoloquy: 6(42) Sex Brain (8)
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PSYCOLOQUY (ISSN 1055-0143) is sponsored by the American Psychological Association (APA).
Psycoloquy 6(42): Estrogen is Still Important
ESTROGEN IS STILL IMPORTANT
Reply to McCarthy on Sex-Brain
Roslyn Holly Fitch
Center for Molecular and Behavioral Neuroscience
Rutgers University
197 University Ave.
Newark, NJ 07102
Victor H. Denenberg
Biobehavioral Sciences Graduate Degree Program
University of Connecticut
Storrs, CT 06269-4154
holly@axon.rutgers.edu
dberg@uconnvm.uconn.edu
Abstract
McCarthy (1995) provides an excellent review of
less known, but potential feminizing agents, and asserts that this
area of research should not focus on estrogen to the exclusion of
other factors. We agree, but also reiterate that data show specific
and significant feminizing effects of estrogen. Such findings argue
that although estrogen may not be the sole feminizing influence, it
is nevertheless a critical one.
Keywords
corpus callosum, development, estrogen, feminization,
ovaries, sensitive period.
1. We find little to add to McCarthy's excellent review of factors other
than ovarian estrogen, and other than ovarian steroids, which may be
involved in female differentiation (McCarthy, 1995). We would only call
attention to a number of studies in which the ovaries have been
removed, and estrogen replacement provided, with comparison against
untreated Ovx subjects (e.g., Frankfurt et al., 1990; Mack et al.,
1993; Pappas et al., 1979; Stewart & Cygan, 1980). By directly
addressing the effects of presence or absence of estrogen, rather than
the ovaries per se, such findings specifically lend support to a
critical role for estrogen in the feminization process. Nevertheless,
such evidence should not preclude investigation of other factors, as
reviewed by McCarthy, which may also play an important role in female
development and sexual differentiation. As has been noted by other
commentators, it seems likely that feminization, and indeed sexual
differentiation in general, reflect highly complex interactions between
intrinsic and extrinsic factors and a dynamic system.
REFERENCES
Fitch, R.H. & Denenberg, V. (1995) A Role For Ovarian Hormones In Sexual
Differentiation of the Brain. PSYCOLOQUY 6(5) sex-brain.1.fitch.
Frankfurt, M., Gould, E., Woolley, C. S. & McEwen, B.S. (1990) Gonadal
steroids modify dendritic spine density in ventromedial hypothalamic
neurons: a golgi study in the adult rat. Neuroendocrinology 51:
530-535.
Mack, C.M., Fitch, R.H., Cowell, P.E., Schrott, L.M. & Denenberg, V.H.
(1993) Ovarian estrogen acts to feminize the rat's corpus callosum.
Developmental Brain Research 71: 115-119.
McCarthy, M. (1995) How About Sexually Differentiating Factors Other
Than Estrogen? PSYCOLOQUY 6(32) sex-brain.7.mccarthy.
Pappas, C.T.E., Diamond, M.C. & Johnson, R.E. (1979) Morphological
changes in the cerebral cortex of rats with altered levels of ovarian
hormones. Behavioral and Neural Biology 26: 298-310.
Stewart, J. & Cygan, D. (1980) Ovarian hormones act early in
development to feminize open field behavior in the rat. Hormones and
Behavior 14: 20-32.
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