Effects of gonadal steroids on attack and on memory processing in the domestic chick

Testosterone is known to facilitate attack and to affect memory processing in young domestic chicks. The two effects are known to have very different latencies following subcutaneous injection of the steroid. Here we show that, in males, the effect on attack is specific to androgens and that estradiol is almost entirely ineffective. The facilitation of attack by testosterone is also very greatly reduced in females. By contrast, for the hormone-dependent changes in a passive avoidance task which reflect changes in memory and attentional processing, estradiol acts at much lower doses than any androgen tested and similar changes are produced by testosterone in both male and female chicks.