Posted by undopaminergic on May 22, 2008, at 10:24:20
I just wanted to highlight the potential for kappa-opioid receptor stimulation to wreak havoc on dopaminergic neurotransmission.
I'm still only scratching the surface of this, but in short, it appears that kappa agonism has the potential to drastically reduce both pre- and postsynaptic dopamine D2 receptor density, and to dysregulate the dopamine transporter protein so that stimulant bidning to the protein is reduced.
Obviously, the above might result in reduced usefulness of many dopaminergic medications, from sulpiride to direct agonists to stimulants.
Kappa-opioid antagonists like buprenorphine may thus be more essential in many more cases than most of us imagined. Indeed, perhaps even full spectrum antagonists like naltrexone would be beneficial from the point of view of combatting lethargy, anhedonia and other hypodopaminergic symptoms.
poster:undopaminergic
thread:830482
URL: http://www.dr-bob.org/babble/neuro/20080418/msgs/830482.html