Posted by Astounder on November 15, 2007, at 19:52:17
In reply to Sigma-1 receptor/Psychotic Depression Ques..., posted by B2chica on November 14, 2007, at 8:59:59
> Sigma-1 receptor
>
> for those that don't want to read the whole thing.
> my question is, how is the sigma-1 receptor different from the DA receptors...is it dopamine effecting?
> do the same meds that are used for DA receptors used with the sigma receptor? and is there much research on it?
> and i would like to learn more about experiences of psychotic depression...any websites..or personal experiences i'd like to know..
> thanks.
Sigma receptors are very, very poorly characterized. We know at least they have something to do with plastic changes in DA neurons, and play a role in drug sensitization. Lots are things are ligands for them: Ketamine, DXM, PCP, kappa-opioidergic analgesics, psychostimulants, some SSRIs, Haldol, various hormones--and of these we really don't know which are agonists and which are antagonists. They were being examined back when dissociatives started to be viewed as a superior drug model of schizophrenia and we didn't really understand their binding well: Two sites were known, the sigma "opioid" receptor, and the PCP-binding site.It's now known that the PCP-binding site is inside the pore of the NMDA channel complex, where ligands act as pure channel blockers (uncompetitive antagonists), and this is the mechanism of action of the dissociatives, including their psychotomimetic effect. The sigma receptor does not seem to mediate the acute actions of the dissociatives, and selective sigma ligands have not shown efficacy as antipsychotics in animal models.
I was originally looking at them at one time as a drug model of depersonalization, but I ended up disappointed.
If you're looking for a novel treatment for psychotic depression, you should look into D-serine, which is a functional agonist of the NMDA receptor PCP binds to. There have been humans studies indicating utility in schizophrenia.
poster:Astounder
thread:795027
URL: http://www.dr-bob.org/babble/20071115/msgs/795344.html