Neural plasticity across hormonal states in females: From modulator to dynamic regulator

Ovarian sex steroid hormones play a critical role in regulating fertility. In addition, these hormones influence behavior and mood across the lifespan in females. Converging evidence from rodent studies and human neuroimaging shows that ovarian hormones dynamically regulate neuronal excitability, synaptic efficacy, and structural remodeling across menstrual/estrous cycles, puberty, and reproductive aging. Estrogen and progesterone reorganize network dynamics and gate plasticity eligibility rather than uniformly scaling synaptic strength, with additional contributions from glia, the extracellular matrix, and neurosteroid signaling. Here we synthesize recent cross-scale advances that link structural and functional changes to cellular and circuit mechanisms, and relate these dynamics to female-biased vulnerabilities in affect, cognition, and social behavior.