TY - JOUR
T1 - Sexual differentiation of brain and behavior in birds
AU - Balthazart, Jacques
AU - Ball, Gregory F.
N1 - Funding Information:
The recent work conducted in the authors’ laboratories was supported by grants from the National Institutes of Health (MH 50388) (to G.F.B. and J.B.); grants from the Belgian FRFC (No. 2.9003.91), the French Community of Belgium (Joint Action No. 93/98-171), the European Community (contract CHRX-CT94-0472), and the University of Liege (Special Funds for Research) (to J.B.); and by grants from the National Science Foundation (IBN 920893) (to G.F.B). The collaboration between J.B. and G.F.B. was also supported by a NATO Collaborative Research Grant (CRG9 10526), sponsored by the Wallonia-MD sister state agreement. We thank Margaret McCarthy, Randy Nelson, Joe Casto, and Dan Bernard for their critical reading and comments on an earlier version of the manuscript.
PY - 1995
Y1 - 1995
N2 - It is currently accepted that most sex differences in brain and behavior do not result from direct genomic actions, but develop following early exposure to a sexually differentiated endocrine milieu. In Japanese quail (Coturnix japonica), in contrast to rodents, the male reproductive phenotype appears to develop in the absence of endocrine influence, and estradiol secreted by the ovary of the female embryo is responsible for the physiologic demasculinization of females. In zebra finches (Taeniopygia guttata), estrogens administered early in life demasculinize copulatory behavior in males, but masculinize the vocal control regions in the brain and singing behavior of females. It is difficult to understand how these behaviors differentiate given that normal untreated males sing and copulate in a male-typical manner, whereas females never show these behaviors. All attempts to resolve this paradox with experiments based on the rodent model of sexual differentiation have been unsuccessful. We propose that copulatory behavior in zebra finches is differentiated in a manner similar to what has been described in quail, but that novel approaches need to be considered to understand the differentiation of the telencephalic song control system. In particular, the possible involvement of afferent input that may differentiate in a steroid-dependent or -independent manner should be thoroughly tested.
AB - It is currently accepted that most sex differences in brain and behavior do not result from direct genomic actions, but develop following early exposure to a sexually differentiated endocrine milieu. In Japanese quail (Coturnix japonica), in contrast to rodents, the male reproductive phenotype appears to develop in the absence of endocrine influence, and estradiol secreted by the ovary of the female embryo is responsible for the physiologic demasculinization of females. In zebra finches (Taeniopygia guttata), estrogens administered early in life demasculinize copulatory behavior in males, but masculinize the vocal control regions in the brain and singing behavior of females. It is difficult to understand how these behaviors differentiate given that normal untreated males sing and copulate in a male-typical manner, whereas females never show these behaviors. All attempts to resolve this paradox with experiments based on the rodent model of sexual differentiation have been unsuccessful. We propose that copulatory behavior in zebra finches is differentiated in a manner similar to what has been described in quail, but that novel approaches need to be considered to understand the differentiation of the telencephalic song control system. In particular, the possible involvement of afferent input that may differentiate in a steroid-dependent or -independent manner should be thoroughly tested.
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U2 - 10.1016/1043-2760(94)00098-O
DO - 10.1016/1043-2760(94)00098-O
M3 - Short survey
AN - SCOPUS:0028940611
SN - 1043-2760
VL - 6
SP - 21
EP - 29
JO - Trends in Endocrinology and Metabolism
JF - Trends in Endocrinology and Metabolism
IS - 1
ER -