Ganaxolone (INN, also known as CCD-1042 and 3a-Hydroxy-3ß-methyl-5a-pregnan-20-one) is a CNS-selective GABA_A modulator that acts on well-characterized targets in the brain known to have anxiolytic and anticonvulsant effects. Ganaxolone protects against seizures in diverse animal models, including the pentylenetetrazol, 6 Hz and amygdala kindling models. Ganaxolone is a positive allosteric modulator of the action of the GABA_A receptor and, unlike benzodiazepines, there does not appear to be tolerance to the anticonvulsant effects of ganaxolone.