[Effect of removal of the olfactory bulbs on the estrous cycle of the mouse].

The effects of removal of the olfactory bulbs on the estrous cycle and the weight of reproductive organs were examined in mice of the IVCS, ICR and C57BL/6 strains. Sham-operated and intact mice served as controls. Virgin female mice were surgically deprived of the olfactory bulbs at 8 weeks of age and caged individually in air-conditioned rooms with controlled lighting (14 hours of light, from 5 a. m. to 7 p. m., each day). Vaginal smears were observed daily. The animals were killed and their principal organs weighed at 6 weeks after the operation. The results obtained were as follows; 1) The olfactory bulb ablation prolonged the length of estrous cycle of mice of the ICR (6.0 days) and C57BL/6 (5.0 days) strains, but did not modify the cycle in those of the IVCS strain (4.0 days). 2) A decrease of ovarian weights by this operation was observed in the mice of the IVCS and ICR strains, but not C57BL/6 strain.