The human gut is lined with tons of serotonin receptors/excretory cells. These cells are theorized to play a role in the anxious feeling that so often manifests itself in our stomachs. Can anyone explain to me what's going on chemically?

Anti-anxiety/depression medicines such as SSRIs or Remeron, etc all work by increasing intracellular serotonin concentration. In my mind I have pictured a bunch of HUNGRY serotonin receptors located in the gut that are PISSED because there isn't enough serotonin to bind to them. Their "hunger" then results in the anxious feelings. Then along comes the SSRI which leads to increased [serotonin] thereby satisfying their "hunger" and decreasing anxiety. Somehow, I don't think this is right. How can receptors be "hungry?"

So I have also theorized that perhaps these gut receptors, once bound with serotonin then upregulate gaba transmission downstream which in turn downregulates secretion of epinephrine from the adrenal cortex reducing sympathetic nervous system activation. This is one possible way of explaining why increasing serotonin would reduce anxiety...

I also get the feeling like I'm leaving the brain out of this too much. Surely it is involved...

My ideas are pretty far out, but maybe they will get you thinking.

Does anyone here know? Or has my question simply not been answered by science yet?

Thanks.

it is much more complex than what could be easily explained. there are many isolated endocrine reactions that can occur in correlation to another, and how the body responds to them person-to-person. it's not a simple matter of "GABA goes here, adrenaline does this, anxiety kicks in", it is a highly involved and sensitive process between endocrine function and the nervous system, ontop of neurological formation and cognitive reasoning. gastroenterology isn't a well known subject, because that shit is disgusting and only a fag would want to study shittubes, but I wouldn't doubt there's some coverage on it out there.

...only a fag would want to study shittubes...
Some nasty fucks EAT those shittubes
http://i29.tinypic.com/2mzywdj.jpg

Peace.