Hormone cycles shape the structure and function of key memory regions in the brain

Hormone levels fluctuate like the tides, ebbing and flowing according to carefully orchestrated cycles. These hormones not only influence the body, but can cross into the brain and shape the behavior of our neurons and cognitive processes. Recently, researchers used modern laser microscopy techniques to observe how fluctuations in ovarian hormones shape both the structure and function of neurons in the mouse hippocampus, a brain region crucial for memory formation and spatial learning in mammals. They found that hormone fluctuations during the mouse estrous cycle, a 4-day cycle analogous to the 28-day human menstrual cycle, powerfully influence the shape and behavior of hippocampal neurons.