The endocannabinoid 2-arachidonoylglycerol mediates D1 and D2 receptor cooperative enhancement of rat nucleus accumbens core neuron firing

Neuroscience. 2011 Oct 13;193:21-33. doi: 10.1016/j.neuroscience.2011.07.055. Epub 2011 Jul 27.


Many motivated and addiction-related behaviors are sustained by activity of both dopamine D1- and D2-type receptors (D1Rs and D2Rs) as well as CB1 receptors (CB1Rs) in the nucleus accumbens (NAc). Here, we use in vitro whole-cell patch-clamp electrophysiology to describe an endocannabinoid (eCB)-dopamine receptor interaction in adult rat NAc core neurons. D1R and D2R agonists in combination enhanced firing, with no effect of a D1R or D2R agonist alone. This D1R+D2R-mediated firing increase required CB1Rs, since it was prevented by the CB1R antagonists AM251 and Rimonabant. The D1R+D2R firing increase also required phospholipase C (PLC), the major synthesis pathway for the eCB 2-arachidonoylglycerol (2-AG) and one of several pathways for anandamide. Further, inhibition of 2-AG hydrolysis with the monoglyceride lipase (MGL) inhibitor JZL184 allowed subthreshold levels of D1R+D2R receptor agonists to enhance firing, while inhibition of anandamide hydrolysis with the fatty acid amide hydrolase (FAAH) inhibitors URB597 or AM3506 did not. Filling the postsynaptic neuron with 2-AG enabled subthreshold D1R+D2R agonists to increase firing, and the 2AG+D1R+D2R increase in firing was prevented by a CB1R antagonist. Also, the metabotropic glutamate receptor 5 (mGluR5) blocker MPEP prevented the ability of JZL184 to promote subthreshold D1R+D2R enhancement of firing, while the 2-AG+D1R+D2R increase in firing was not prevented by the mGluR5 blocker, suggesting that mGluR5s acted upstream of 2-AG production. Thus, our results taken together are consistent with the hypothesis that NAc core eCBs mediate dopamine receptor (DAR) enhancement of firing, perhaps providing a cellular mechanism underlying the central role of NAc core D1Rs, D2Rs, CB1Rs, and mGluR5s during many drug-seeking behaviors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects*
  • Action Potentials / physiology
  • Analysis of Variance
  • Animals
  • Dopamine Agents / pharmacology
  • Drug Interactions
  • Enzyme Inhibitors / pharmacology
  • Glycerides / pharmacology*
  • In Vitro Techniques
  • Male
  • Neurons / drug effects*
  • Neurons / physiology
  • Nucleus Accumbens / cytology*
  • Patch-Clamp Techniques
  • Piperidines / pharmacology
  • Pyrazoles / pharmacology
  • Rats
  • Rats, Wistar
  • Receptor, Cannabinoid, CB1 / agonists
  • Receptor, Cannabinoid, CB1 / antagonists & inhibitors
  • Receptor, Metabotropic Glutamate 5
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine D2 / metabolism*
  • Receptors, Metabotropic Glutamate / metabolism
  • Rimonabant
  • Time Factors
  • Type C Phospholipases / metabolism


  • Dopamine Agents
  • Enzyme Inhibitors
  • Glycerides
  • Grm5 protein, rat
  • Piperidines
  • Pyrazoles
  • Receptor, Cannabinoid, CB1
  • Receptor, Metabotropic Glutamate 5
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Receptors, Metabotropic Glutamate
  • AM 251
  • Type C Phospholipases
  • 1-arachidonyl monoglyceride
  • Rimonabant