Neuroactive steroids are also called as neurosteroids . They are endogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. Neuroactive steroid refers to steroids that are synthesized by an endocrine gland that reach the brain through the bloodstream and have effects on brain function. Neurosteroids have a wide range of potential clinical applications from sedation to treatment of epilepsy and traumatic brain injury. Ganaxolone is a synthetic analog of the endogenous neurosteroid. Allopregnanolone is under investigation for the treatment of epilepsy.
Valproic acid was first synthesized in 1882 by Beverly S. Burton as an analogue of valeric acid , found naturally in valerian .  Valproic acid is a carboxylic acid , a clear liquid at room temperature. For many decades, its only use was in laboratories as a "metabolically inert" solvent for organic compounds. In 1962, the French researcher Pierre Eymard serendipitously discovered the anticonvulsant properties of valproic acid while using it as a vehicle for a number of other compounds that were being screened for antiseizure activity. He found it prevented pentylenetetrazol -induced convulsions in laboratory rats .  It was approved as an antiepileptic drug in 1967 in France and has become the most widely prescribed antiepileptic drug worldwide.  Valproic acid has also been used for migraine prophylaxis and bipolar disorder.