Posted by undopaminergic on May 23, 2008, at 16:11:02
In reply to Re: Sulpiride and Abilify questions..., posted by undopaminergic on May 23, 2008, at 15:37:34
> > Postsynaptic agonists overule presynaptic agonists because they directly stimulate postsynaptic receptors regardless of the decrease in DA synthesis and release.
> That is dose dependent. At low doses of sulpiride/amisulpride and dopamine direct agonists, the presynaptic effects predominate.
Furthermore, with the possible exception of some ergot-based dopamine agonists, they don't stimulate D1-receptors even at high concentrations, and hence fail to make up for the deleterious effects of reduced synthesis and release of endogenous DA. Insufficient (or excessive) stimulation of D1-receptors disturbs working memory, among other things. Fortunately in the case of aripiprazole, antagonism of serotonin 5-HT2A and 5-HT2C antagonism may possibly mitigate this problem.