Posted by JohnX2 on March 18, 2002, at 14:02:32
In reply to Re: dopamine receptor sensitivity, TD, poop out?, posted by SLS on March 18, 2002, at 8:26:30
> At first, the term "dopamine depletion" didn't seem right to me. Amphetamines cause dopamine depression, don't they? Dopamine is depleted because the neuron is forced to release more than it is designed to, compounded by the activation of the negative feedback loop. I wouldn't think that the few days it takes to develop tolerance is the result of changes in presynaptic receptor binding. Do you? Now, if SSRIs tend to result in a reduction of neuronal firings downstream, how does this result in depetion? Do you think the presynaptic regulatory system "atrophies", with some sort of reduction in the amount of machinery available to synthesize and release neurotransmitter. Is their less dopamine because so little is released? A bit paradoxical. I guess this could be defined as "depletion".
>I need to learn more about dopaminergic systems, its not my strong point. Rambling off the top of my head...
I'm not sure if what you or I experience which is a poop out after a response is related to maladaptations that occur during the experiment at hand. I believe it may be a pre-existing "setup" in the dopaminergic system from prior exposure to medications..whatever.
But just looking at the way these receptors autoregulate themselves, you can see major trouble on the wall. It doesn't take a rocket scientist to see that this system can get whacked into some pathological behavior.
I would think if things really got out of whack on these dopamine receptors, one could get stuck in an inescapable rathole (chaotic fluctuations). Am I correct?
You would need to stabilize this feeback loop somehow.
Anyways, it seems these same sort of dopamine chaotic feedback loops may cause these "tics",TD,etc. So if this is so, it seems as though someone claims to have found mechanisms to break/tame these malfunctioning pathological feedback loops.
Can these same sort of pathological feedback loops/fluctuations that cause "tics", "TD", etc in the respective dopamine system exist elsewhere in the limbic system and give erratic antidepressant responses? Would similar treatment strategies work?
John
>
> - Scott
poster:JohnX2
thread:98489
URL: http://www.dr-bob.org/babble/20020318/msgs/98595.html