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D E Gonzalez

Publications and source records attributed to D E Gonzalez.

3 recordsLinked to original sources
PubMed1986

Maternal behavior in cyclic and androgenized female rats: role of ovarian hormones.

A comparative study on the induction of maternal behavior (MB) in response to pups was carried out in cyclic and androgenized rats. Moreover, the effects of exposure to ovarian hormones on the induction of MB in response to pups were studied in cyclic and androgenized rats. A high percentage of androgenized and proestrus rats displayed MB after 48 hr of exposure to pups (87.9% and 87.5% respectively). Diestrus day-1 rats were significantly less maternal (37.5%). Ovariectomy did not impair MB in androgenized rats. High serum progesterone levels induced in androgenized rats by treatment with 10 I.U. of HCG (40 hours before pup presentation) or with progesterone silastic implants prevented the onset of MB. Ovariectomy performed 8 hours before HCG administration restored MB. When behavioral testing began 72 hours after HCG treatment, 75% of the rats were maternal 12 hr after exposure to pups. This rapid onset of MB in proestrus and androgenized rats appeared to be estrogen dependent. The presence of progesterone inhibited the maternal response of androgenized rats.

Animals↗
PubMedDate not supplied

The capacity to develop maternal behavior is enhanced during aging in rats.

The induction of maternal behavior (MB) in response to stimulation by pups was studied in aged rats (19-20 months old). We used virgin female rats, neonatally androgenized female rats and male rats. Both groups of female rats showed a constant estrous vaginal smear. Maternal responsiveness was compared with that of young rats (3-4 months old). Normal and androgenized female aged rats showed a very high percentage of immediate maternal responsiveness and 100% of the rats were fully maternal within 24 hr of testing. The percentage of cyclic and androgenized young rats showing MB were significantly lower. Chronic ovariectomy performed 17 months before testing but not acute ovariectomy abolished MB. Estrogen treatment (5 micrograms 15 hours before pup presentation) to chronically ovariectomized aged rats was not sufficient to reestablish significantly the capacity of the normal female aged rats to become short-latency maternal. Young and aged male rats showed no difference in maternal responsiveness to the presence of foster pups. The percentage of maternal aged male rats was significantly lower than that of the normal and androgenized aged female rats, whereas young male and female rats showed a similar level of MB, indicating a sex difference in the development of MB with age. In conclusion the high percentage of rats becoming maternal and the short-latency maternal responsiveness in aged female rats appears to be the result of a prolonged estrogen and/or prolactin stimulation.

Aging↗