Rouibi Khalil, Rompré Pierre-Paul
Faculté de médecine, Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada.
Faculté de médecine, Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada.
Peptides. 2014 Aug;58:103-7. doi: 10.1016/j.peptides.2014.06.010. Epub 2014 Jun 23.
Previous studies have shown that repeated central injections of neurotensin, or its active analog, D-Tyr([11])neurotensin, sensitize to the locomotor stimulant effect of amphetamine. The development of sensitization to amphetamine can be modulated by contextual stimuli associated with the drug and as a consequence the expression of sensitization becomes context-dependent. The present study was thus aimed at determining whether the induction of amphetamine sensitization by neurotensin is modulated by the context in which neurotensin is administered. Different groups of adult male Long Evans rats were injected on four occasions with D-Tyr([11])neurotensin (18 nmol/10 μl; i.c.v.) in the locomotor activity cages (paired group) or in their home cage (unpaired group); control group received vehicle injection in both environments. One week after the last central injection, the locomotor response to a single dose of amphetamine (0.75 mg/kg; i.p.) was measured in all the rats. Results show that amphetamine induced higher ambulatory, non-ambulatory and vertical activity in the paired group than in the control group confirming the sensitization effect. The paired group also displayed significant higher ambulatory activity than those in the unpaired group, confirming that the expression of sensitization was context-dependent. This context-dependency was not found however for amphetamine-induced non-ambulatory and vertical activity suggesting that neurotensin can induce both a context-dependent and context-independent sensitization.
先前的研究表明，反复向中枢注射神经降压素或其活性类似物D-Tyr([11])神经降压素，会使机体对苯丙胺的运动兴奋作用产生敏化。对苯丙胺敏化的发展可受到与该药物相关的环境刺激的调节，因此敏化的表达变得依赖于环境。本研究旨在确定神经降压素对苯丙胺敏化的诱导是否受神经降压素给药环境的调节。将成年雄性Long Evans大鼠分成不同组，在运动活动笼中（配对组）或在其饲养笼中（非配对组）四次注射D-Tyr([11])神经降压素（18 nmol/10 μl；脑室内注射）；对照组在两种环境中均注射溶剂。在最后一次中枢注射一周后，测定所有大鼠对单剂量苯丙胺（0.75 mg/kg；腹腔注射）的运动反应。结果显示，与对照组相比，配对组中苯丙胺诱导的走动、非走动和垂直活动更高，证实了敏化效应。配对组的走动活动也显著高于非配对组，证实敏化的表达依赖于环境。然而，对于苯丙胺诱导的非走动和垂直活动，未发现这种环境依赖性，这表明神经降压素可诱导环境依赖性和非环境依赖性敏化。
