Sculpting the hippocampus from within: stress, spines, and CRH.

Learning and memory processes carried out within the hippocampus are influenced by stress in a complex manner, and the mechanisms by which stress modulates the physiology of the hippocampus are not fully understood. This review addresses how the production and release of the neuropeptide corticotropin-releasing hormone (CRH) within the hippocampus during stress influences neuronal structure and hippocampal function. CRH functions in the contexts of acute and chronic stresses taking place during development, adulthood and aging. Current challenges are to uncover how the dynamic actions of CRH integrate with the well-established roles of adrenal-derived steroid stress hormones to shape the cognitive functions of the hippocampus in response to stress.