Table 1.

summarizes differences between female (F) and male (M) rats in certain conditioning paradigms. It is noted whether the difference has been shown in acquisition of the learned response or during retention and/or extinction studies (slower extinction is indicated with the symbol >). The arrows depict the effect of ovariectomy of adult females or castration of adult males during acquisition or extinction of the learned responses (slower extinction is indicated with the arrow pointing down). Wherever data are available, the effects of hormones during development of the brain are also summarized. Please see text for different variations of tasks, for controversial findings between studies and for relevant references.

Task	Sex difference	Ovariectomy	Castration	Organizational effects
Eyeblink conditioning	F > M acquisition - retention	Acquisition	No effect	Acquisition in masculinized females
Contextual fear conditioning	M > F acquisition - retention	Extinction	No effect	-
Fear potentiated startle	F > M acquisition	Opposite effects of estrogens and progesterone	No effect	-
Light enhanced startle	F > M acquisition	No effect	Acquisition	-
Active avoidance	F > M acquisition - extinction	No effect Estrogens effects	Acquisition	Acquisition in masculinized females treated with testosterone in adulthood
Differential reinforcement of low rate responding	F > M acquisition	Acquisition	-	No effect
Conditioned taste aversion	M > F extinction	No effect Estrogens effects	Extinction	-