“…8,9 Neurosteroids, such as 3R-hydroxy-5R-pregnan-20-one (allopregnanolone, 1), 3R-hydroxy-5 -pregnan-20-one (pregnanolone, 2), and their 21-hydroxy derivatives, that is, 3R,21-dihydroxy-5R-pregnan-20-one (allotetrahydrodeoxycorticosterone, 3) and 3R,21-dihydroxy-5 -pregnan-20-one (tetrahydrodeoxycorticosterone, 4), have been proven to be anticonvulsant, anesthetic, antidepressant, and neuroprotectant agents. [10][11][12][13][14][15][16][17][18] In vitro assays reflect this positive modulation by showing an increase of both the Cl -influx through the GABA A receptor and the binding of GABA agonists or benzodiazepines. 8,14,15,[19][20][21][22][23] Although acting at higher concentrations than benzodiazepines and barbiturates, neurosteroids are valued 24 because they combine the effects of both and have fewer and less severe side effects.…”