Rapid signaling of steroid hormones in the vertebrate nervous system

Abstract

Steroid hormones easily cross the blood-brain barrier because of their physicochemical lipid solubility. The hormones act through nuclear receptor-mediated mechanisms and modulate gene transcription. In contrast to their genomic actions, the non-genomic rapid action of steroid hormones, acting via various types of membraneassociated receptors, reveals pharmacological properties that are distinct from the actions of the intracellular nuclear receptors. As a result, non-genomic rapid actions have gained increased scientific interest. However, insight into the phylogenic and/or comparative actions of steroids in the brain is still poorly understood. In this review, we summarize recent findings concerning the rapid, nongenomic signaling of steroid hormones in the vertebrate central nervous system, and we discuss (using a comparative view from fish to mammals) recently published data regarding the mechanism underlying physiology and behavior.