The Neurosteroids

Steroids are generally considered to be hormones.

They are produced and released by endocrine glands in the periphery (the gonads and the adrenal cortex).

Being hydrophobic they have no problem in crossing the blood-brain barrier and thus having central targets as well as peripheral targets.

Because their mechanism of action is to activate gene expression they generally work very slowly.

Thus, it was very surprising when fast actions of steroids on brain tissue was first reported.

Research revealed that some steroids can effect the working of the GABAa receptor, thus accounting for their fast actions.

More importantly, this research lead to the discovery of an entire new class of steroids, the so-called neurosteroids.

Neurosteroids are steroids that are produced in the brain itself, by neurons and glial cells.

There are two groups of neurosteroids, those that strengthen or potentiate the action of GABA on the GABAa receptor and those that weaken the action of GABA on its receptor.