The effects of ECS and ES (stimulating on the grids-floor) on the sexual cycle of mature rats have been studied. Estrus cycles were observed by the vaginal smear method and were employed as a measure of behavioral and endocrine activity.
The main results of Exp. I and II are as follows:
(1) The length of the estrus cycle in normal rats averaged 101.6±17.8 hours in Exp. I, and 96.0±1.0 hours in Exp. II.
For rats of both experiments, daily stimulation started when the smear was on the first day of the fourth estrus period.
(2) In Table 1 are shown the averag es of the normal cycle, the first cycle and the succeeding cycles after starting the shock treatments.
The averages of all estrus cycles administered by a series of ECS treatments were significantly related to the number of administrations given (p<0.01). Their effects were cumulative, that is, when numbers of ECS treatments increased, delay in resumption of normal sexual cycle increased.
(3) In Exp. II the results indicate no significant effects of number of ES treatments on estrus cycles, but ES treatments significantly postponed the cycle in all groups (Table 2).
Responses to ES treatments were divided into three types; startle response (S-R) violent running response (V-R), and tonic clonic convulsion (T-C) (Table 3).
(4) These results indicate that ECS or ES affected the length of the estrus cycle and the effect was shown as a function of the number of administrations in Exp. I and, in part at least, in Exp. II.
It may be suggested that these findings might depend on the changes in hormone level which suggests confirmation of relationship between the behavior disturbance and physiologic-endocrine level.
Since the behavioral effects of ECS occur under functional stimulation of pituitary adreno-cortical mechanism as suggested by Rosvold and others (3, 11, 17) and the writer (15, 16), the present results may be interpreted by assuming some pituitary gonadtropic mechanism relating to their behavioral effects.
In conclusion, the results of the present investigation, along with previous works, support the hypothesis that some physiologic endocrine mechanism may be associated with behavioral disturbances produced, whatever the stress may be.
