| First Author | Zachariou V | Year | 2002 |
| Journal | Biol Psychiatry | Volume | 51 |
| Issue | 8 | Pages | 612-20 |
| PubMed ID | 11955461 | Mgi Jnum | J:102534 |
| Mgi Id | MGI:3607733 | Doi | 10.1016/s0006-3223(01)01318-x |
| Citation | Zachariou V, et al. (2002) Reduction of cocaine place preference in mice lacking the protein phosphatase 1 inhibitors DARPP 32 or Inhibitor 1. Biol Psychiatry 51(8):612-20 |
| abstractText | BACKGROUND: Modulation of protein phosphorylation by dopamine is thought to play an important role in drug reward. Protein phosphatase-1 (PP-1) is known to mediate some of the changes in neuronal signaling that occur following activation of the dopaminergic system. METHODS: Two endogenous inhibitors of PP-1 are dopamine and cyclic 3', 5' adenosine monophosphate-regulated phosphoprotein (DARPP-32) and Inhibitor-1 (I-1). Knockout mice lacking one or both of these PP-1 inhibitors were tested for responses to cocaine using in vivo amperometry and conditioned place preference. RESULTS: Presynaptic dopaminergic function appears to be unaffected by these mutations because stimulation-evoked changes in extracellular dopamine levels were unchanged between wild type mice and mice lacking one or both of these PP-1 inhibitors. In contrast, conditioned place preference to cocaine is reduced in mice lacking DARPP-32, I-1, or both phosphoproteins. This does not appear to be due to a learning deficit because mice lacking both DARPP-32 and I-1 show normal passive avoidance learning. CONCLUSIONS: These data imply that increased PP-1 function as a result of deficits in DARPP-32 or I-1 is sufficient to decrease the rewarding properties of cocaine. Furthermore, the mechanism for this altered cocaine place preference does not involve alteration of dopamine release or reuptake. |
