Abstract: | In female rats various parameters and rhythmical structure of forced swimming underwent unsignificant fluctuations during estrus cycle. Ovariectomy changed the swimming time course and increased the rhythmical index of depression without other serious disturbances of the behavioural "despair" test. After chronic estradiol these shifts were partially eliminated. It is suggested that considerable disturbances of gonadal function may be cause of desynchronousness which facilitated the development of depression. |