Posted by CrAzYmEd on May 28, 2010, at 16:29:00
In reply to Re: 5HT2A-antagonism + 5HT2C-agonism Would Be Ideal, posted by CrAzYmEd on May 28, 2010, at 16:22:21
But this is about fear tough, not depression, but werent SSRI's also capable of increasing depression when starting the treatment, dont exactly remember, i actually tought that this was also due to 5HT2C agonism, but 5HT2C doesnt appear to be the big gangster as i first tought.
Acute SSRIs Increase Conditioned Fear Expression: Blockade with a 5-HT2C Receptor Antagonist
N.S. Burghardt,1 D.E.A. Bush,1 B.S. McEwen,2 and J.E. LeDoux1Background
SSRIs effectively treat various anxiety disorders, although symptoms of anxiety are often exacerbated during early stages of treatment. We previously reported that acute treatment with the SSRI citalopram enhances the acquisition of auditory fear conditioning, which is consistent with the initial anxiogenic effects reported clinically. Here, we extend our findings by assessing the effects of acute SSRI treatment on the expression of previously acquired conditioned fear.Results
A single pre-testing injection of the SSRIs citalopram or fluoxetine significantly increased fear expression. There was no effect of the antidepressant tianeptine, or the norepinephrine reuptake inhibitor, tomoxetine, indicating that this effect is specific to SSRIs. The SSRI induced enhancement in fear expression was not blocked by tropisetron, a 5-HT3 receptor antagonist, but was blocked by SB 242084, a specific 5-HT2C receptor antagonist.Conclusions
Enhanced activation of 5-HT2C receptors may be a mechanism for the anxiogenic effects of SSRIs observed initially during treatment.
poster:CrAzYmEd
thread:948688
URL: http://www.dr-bob.org/babble/neuro/20100223/msgs/949293.html