19799936 |
Uslaner JM, Drott JT, Sharik SS, Theberge CR, Sur C, Zeng Z, Williams DL, Hutson PH: Inhibition of glycine transporter 1 attenuates nicotine- but not food-induced cue-potentiated reinstatement for a response previously paired with sucrose. Behav Brain Res. 2010 Feb 11;207(1):37-43. Epub 2009 Sep 30. RATIONALE: Compounds which decrease NMDA receptor functioning, such as PCP and ketamine have abuse liability, whereas co-agonists of the NMDA receptor attenuate some of the behavioral and neurochemical effects of stimulant drugs. Here we examined the effects of a glycine transporter (GlyT1) inhibitor, which elevates glycine and hence NMDA signaling, on the behavioral effects of nicotine. OBJECTIVES: To examine the influence of a novel potent, selective, and brain penetrant GlyT1 inhibitor, compound 5 {(2-chloro-N-[1-(ethylsulfonyl)-4-isobutylpiperidin-4-yl] methyl)}-4-(trifl uoromethyl) benzamide; human IC (50)=22 nM; rat=30 nM), on nicotine-induced potentiation of progressive ratio responding for a food reward and nicotine- and food-induced cue-potentiated reinstatement for a response previously paired with sucrose. RESULTS: Compound 5 (33 mg/kg; p.o.; achieving approximately 62% GlyT1 blockade) significantly attenuated nicotine-, but not food-induced cue-potentiated reinstatement for a response previously paired with sucrose whereas a lower dose (11 mg/kg, which achieved approximately 34% GlyT1 blockade) did not. The effect of the higher dose was similar to that observed for mecamylamine (1mg/kg i.p.), a non-selective nicotinic receptor antagonist. CONCLUSIONS: These results suggest that compound 5 influences the ability of nicotine to promote reinstatement in the presence of a cue embedded with incentive motivation. Given the hypothesized contribution of reinstatement and conditioned stimuli to drug abuse and relapse, these findings suggest that GlyT1 inhibitors could have utility for treating nicotine addiction. |
1(0,0,0,1) |