TY - JOUR
T1 - Lack of activational influence of ovarian hormones on the size of the female rat's corpus callosum
AU - Mack, Christine M.
AU - Fitch, Roslyn H.
AU - Hyde, Lynn A.
AU - Seaman, Amy Jo
AU - Bimonte, Heather A.
AU - Wei, Wei
AU - Denenberg, Victor H.
PY - 1996/8
Y1 - 1996/8
N2 - The sex difference in the midsagittal area of the adult rat corpus callosum (CC) has been shown to be mediated in part, by gonadal steroids in early development, with the sensitive period of hormone action in the female extending at least up to postnatal day 25. Given this prolonged sensitivity, the current study attempted to delineate organizational vs. activational influences of gonadal hormones on the female rat CC. In Experiment 1, callosal size was examined across the estrous cycle at 52 and 0 days of age. In Experiment 2, females were ovariectomized at 78 days and CC parameters assessed at 110 days. Last, in Experiment 3, females were ovariectomized at 78 days and sacrificed at 110 days. Last, in Experiment 3, females were ovariectomized at 78 days and sacrificed at 110 days; in addition, sham females were sacrificed during proestrus or estrus. Neither stage of estrous cycle nor adult ovariectomy affected midsagittal CC size. These results provide evidence for organizational effects of ovarian steroids on the female callosum, with the sensitive period of hormone action ending sometime between days 25 and 78.
AB - The sex difference in the midsagittal area of the adult rat corpus callosum (CC) has been shown to be mediated in part, by gonadal steroids in early development, with the sensitive period of hormone action in the female extending at least up to postnatal day 25. Given this prolonged sensitivity, the current study attempted to delineate organizational vs. activational influences of gonadal hormones on the female rat CC. In Experiment 1, callosal size was examined across the estrous cycle at 52 and 0 days of age. In Experiment 2, females were ovariectomized at 78 days and CC parameters assessed at 110 days. Last, in Experiment 3, females were ovariectomized at 78 days and sacrificed at 110 days. Last, in Experiment 3, females were ovariectomized at 78 days and sacrificed at 110 days; in addition, sham females were sacrificed during proestrus or estrus. Neither stage of estrous cycle nor adult ovariectomy affected midsagittal CC size. These results provide evidence for organizational effects of ovarian steroids on the female callosum, with the sensitive period of hormone action ending sometime between days 25 and 78.
KW - Activational influence
KW - Corpus callosum
KW - Female rat
KW - Ovarian hormones
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U2 - 10.1016/0031-9384(96)00052-2
DO - 10.1016/0031-9384(96)00052-2
M3 - Article
C2 - 8840902
AN - SCOPUS:0030220682
SN - 0031-9384
VL - 60
SP - 431
EP - 434
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 2
ER -