It has been known for many years that steroids influence many processes by genome activation. In 40-th the fast (anesthetic)-effect of steroids on neuronal activity was discovered, and later the molecular mechanism of steroid action as modulators of GABA(A) receptors was documented. Such kind of influence of neuronal activity is characteristic for some glucocorticosteroids and some derivatives of androsterone and progesterone (for instance: THDOC, THP). The endogenous production of several steroids in the brain was proved. Recently modulatory effect (anti-anesthetic properties) of sulphate esters of pregnenolone (P) and dehydroepiandrosterone (DHEA) on GABAA receptors was discovered. The steroid influence on the neuronal activity is still poorly documented and requires further investigations.