Stress increases addictive behaviors and is a common cause of relapse. Corticotropin-releasing factor (CRF) plays a key role in the modulation of drug taking by stress. However, the mechanism by which CRF modulates neuronal activity in circuits involved in drug addiction is poorly understood. Here we show that CRF induces a potentiation of NMDAR (N-methyl-D-aspartate receptor)-mediated synaptic transmission in dopamine neurons of the ventral tegmental area (VTA). This effect involves CRF receptor 2 (CRF-R2) and activation of the phospholipase C (PLC)-protein kinase C (PKC) pathway. We also find that this potentiation requires CRF binding protein (CRF-BP). Accordingly, CRF-like peptides, which do not bind the CRF-BP with high affinity, do not potentiate NMDARs. These results provide evidence of the first specific roles for CRF-R2 and CRF-BP in the modulation of neuronal activity and suggest that NMDARs in the VTA may be a target for both drugs of abuse and stress.
Bibliographical noteFunding Information:
We thank R.C. Malenka, R.O. Messing, A.J. Ravindranathan, J. Roeper, and Y. Shaham for many useful comments; the members of the Malenka lab and Bonci lab for helpful discussions; and L. Daitch for proofreading the manuscript. This work was supported by funds provided by the State of California for medical research on alcohol and substance abuse through the University of California, San Francisco (A.B., T.L.C, M.A.U., R.Y., and D.R.) and by the National Institute of Neurological Disorders and Stroke (K23 NS42072) (V.S.).