Posted by MB on February 14, 2004, at 13:30:45
In reply to Dopamine Myth, posted by PsychoSage on February 13, 2004, at 13:50:20
I think it all depends on where in the brain the dopamine is. When extra dopamine is made available to the accumbal shell in the limbic system, pleasure results. Extra dopamine in other brain regions will have other effects. Opiates increase the amount of dopamine available to the accumbens. Dopamine is often an excitatory transmitter, but in that particular septal nucleus, it has an inhibitory effect. There are also GABA receptors on the accumbens, and activation of them will (like the activation of dopamine receptors in the same area) decrease the firing rate of the neurons efferent from that nucleus. It is postulated that this is why depressants like benzos and barbiturates are reinforcing (producing pleasure) even though they are techincally "depressants".
MB
poster:MB
thread:312887
URL: http://www.dr-bob.org/babble/20040210/msgs/313253.html