Glial cells are increasingly recognized as active regulators of neural circuit development, plasticity, and repair. This seminar will highlight how supporting cells in the inner ear and myelinating glia in auditory and prefrontal circuits control circuit function. Our work in the inner ear shows how glia influence hearing, in particular the recently described “hidden hearing loss”, while our studies of juvenile social isolation demonstrate our early-life experience reshapes prefrontal myelination, neuronal function, and behavior through epigenetic mechanisms. Together, these findings point to glia‑mediated synaptic and myelin changes as key, complementary pathways through which development, experience, and aging impact circuit performance.
