Estrogen and memory in youth

The role of steroid hormone estrogen on sex behavior in mammals is well established; moreover, its influence on other types of behavior, such as mood and cognition, has also been recognized. This effect can be explained by the widespread presence of estrogen receptors in many regions involved in cognitive processes, such as learning and memory, including the hippocampal formation, amygdala, and cerebral cortex. Another reason may lie in the modulator role of estrogen on several neurotransmitter systems, such as acetylcholine, catecholamines, serotonin, and GABA, in mammals. In fact, estrogen acts on the central nervous system both through genomic mechanisms, modulating synthesis, release and metabolism of neurotransmitters, neuropeptides and neurosteroids, and through non-genomic mechanisms, influencing excitability, synaptic function and morphological features. Research conducted in our laboratories and in others, with the objective of identifying the estrogen actions on cognitive functions, is here reported. In particular, after briefly summarizing the role of estrogen receptors in the brain neurobiology, and the interaction between estrogen and neuromodulation/neurotransmission systems, our findings on the role of estrogen on memory in mammals (rodents, monkeys and humans) are described. In particular, our results on rats support the hypothesis that the physiological fluctuations of estrogen during the estrous cycle can differentially affect the performance on working and reference memory tasks. Our findings in human and non-human primates evidence the effect of estrogen on working memory. Our data could also represent a useful tool for investigating emotional disturbances linked to menstrual cycle phases and menopause in women.