Brain estrogen production and the encoding of recent experience

•We review recent literature related to rapid estrogen synthesis and cognition.•Aromatase is typically found in cognitive-related brain regions across vertebrates.•In vivo detection of neuroestrogens during learning provides new insights.•17β-Estradiol (E2) post-training can enhance memory consolidation.•Central E2 suppression during training may important for encoding recent experience.

The vertebrate central nervous system integrates cognition and behavior, and it also acts as both a source and target for steroid hormones like estrogens. Recent exploration of brain estrogen production in the context of learning and memory has revealed several common themes. First, across vertebrates, the enzyme that synthesizes estrogens is expressed in brain regions that are characterized by elevated neural plasticity and are also integral to the acquisition, consolidation, and retrieval of recent experiences. Second, measurement and manipulation of estrogens reveal that the period following recent sensory experience is linked to estrogenic signaling in brain circuits underlying both spatial and vocal learning. Local brain estrogen production within cognitive circuits may therefore be important for the acquisition and/or consolidation of memories, and new directions testing these ideas will be discussed.