Recent evidence indicates that, besides their hormonal actions at the genetic level, estrogens such as 17 beta-estradiol also influence brain function by direct effects on neuronal membranes.
Thus, brain-derived estrogens are increasingly considered genuine neuromodulators. It is unclear, however whether neuroestrogen production is controlled via electrochemical events that are the hallmark of neurotransmitter-based cell-to-cell communication.
In this study, Luke Remage-Healey and colleagues from the University of California Los Angeles (UCLA) provide evidence that estrogens are produced in the brain’s nerve cell terminals on demand and that estradiol may acts remarkably like a classic neurotransmitter.
They found that neuroestrogen fluctuations are dependent on summed (30 min) electrochemical events and that this process is controlled by specific, depolarization-sensitive, calcium-dependent events within forebrain presynaptic terminals of the zebra finch.
The authors discuss that these findings begin to characterize a fundamental mechanism for rapid, presynaptic estrogen provisioning within neural circuits.