[Avoidance learning in rats treated with estrogens]

Male and female rats were treated with estradiol benzoate in the 5 degrees day of life. The avoidance conditioning, tested after 65 days, was significatively impaired in males treated with estradiol, a significative retardation was observed in females treated, but no significant end-difference versus no-treated females. It is supposed that a hormone induced synaptic shaft/spines ratio in preoptic area may be involved in avoidance conditioning.