[Effect of progesterone administration in newborns rats on Morris water maze learning susceptibility after adolescence]

Although the roles of steroid hormones in the activation and maintenance of reproductive function are proved well, emerging evidence indicated that these steroids influence on performance of learning and memory. These effects are complex and vary with task, gender, and age, as well as the regimens of steroid exposure. This study was carried out in order to assess the role of progesterone administration in newborns rats on Morris water maze learning ability after adolescence. This experimental study was carried out on 36 newborns Wistar rats. Rats were divided randomly into 6 groups; female progesterone, male progesterone, female sesamoide, male sesamoid rats and male and female control rats. Progesterone groups were treated with a single injection of progesterone [100 mg/kg] and sesamoid groups were received the same volume of sesamoid oil as the progesterone vehicle in day 1 or 2 after birth, 60 days later, spatial memory ability was determined in Morris water maze. The results of this study show that water maze learning can enhance by administration of sesamoid oil in newborn female pups in compared to progesterone and control groups [p<0.05]. In addition, adding progesterone to sesame oil reduce water maze learning to control level. The hypothesis that progesterone impaired spatial reference memory in female rats was supported by this experiment

[Effect of progesterone administration in newborns rats on pentylenetetrazol kindling susceptibility after maturity]

Regarding the high prevalence of epileptic seizures, its complications and the necessity to control them, this study was carried out in order to assess the role of progesterone administration in newborn rats on Pentylenetetrazol [PTZ] kindling susceptibility after maturity. This experimental study was carried out on 32 newborn Wistar rats. Rats were randomly divided into four groups, which are as follows: progesterone-injected females, progesterone-injected males, sesamoid-injected females and sesamoid-injected males. Progesterone and sesamoid groups were injected with progesterone [100 mg/Kg] and sesamoid [100 mg/Kg] respectively. Sixty days after injection chemical kindling in the rats was analyzed by PTZ administration. Progesterone significantly increased the susceptibility for PTZ kindling in female rats however; it did not have a significant effect on seizure parameters in male rats. The results of this study suggest that chronic administration of progesterone can only increase susceptibility for chemical kindling in female rats and not in the males