Posted by Questionmark on July 22, 2004, at 2:51:32
In reply to Re: What chemical is released when you drink caffein? » cherylann, posted by Larry Hoover on July 21, 2004, at 7:22:03
> The neurological effects of caffeine, the alerting and cognitive enhancement, are primarily due to caffeine's stimulation of adenosine A1 receptors. Some people get the opposite effect from coffee. It makes them dopey. They tend towards adenosine A2 effects. There is also a rather broad increase in dopamine activity, which is generally associated with pleasurable feelings.
Larry, just wanted to point out that caffeine is an antagonist of adenosine receptors (and mostly, if not entirely, the A[2a] receptors, or A[2] receptors at least-- i'm pretty sure) and does not stimulate them.
For others wondering, this is a significant factor in caffeine's stimulatory effects because adenosine is an inhibitory neurotransmitter, therefore inhibiting the inhibition (as caffeine does) results in stimulation-- or enhanced release of the more "stimulatory" neurotransmitters, such as NE and dopamine.
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