Anyone Familiar with Neurosteroids That Bind to GABA Receptors?

I read about neurosteroids but I'm not that familiar with them. Does anyone know if they can be bought? I see that they bind to the neurosteroid transmitter site on the GABA receptor. I think more people are familiar with the barbiturate and benzodiazepine site.

This is a picture on the GABA receptor:


Source: https://t3.kn3.net/taringa/3/2/8/8/6/3/ezesl/A24.jpg

If anyone can share some info on this, it would be great.

 

Here's a press release about Ganaxolone:
http://ir.marinuspharma.com/releasedetail.cfm?releaseid=1031834

They are in Phase 2 Clinical trial to treat epilepsy.