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        在压力较大的人群可能倾向于暴饮暴食或者沉溺于吸毒。最新的研究成果表明，这与压力而诱导的促肾上腺皮质激素在大脑中的过量释放有关。
        研究中，使用大鼠作为模型，当用糖球作为奖赏的诱导下其大脑中释放相当于处于较重压力下的人群的促肾上腺皮质激素释放因子（CRF），模拟同样处于压力条件下人群的状态。研究结果解释了处于较大压力下渴望回报人群容易暴饮暴食或者沉溺于吸毒的原因。
        研究者向大鼠脑内与奖赏和压力刺激相关的部位注射高剂量(500ng/0.2 ml)及少剂量(250ng/ 0.2 ml)的CRF后，喂给大鼠较少量的糖球，同时排出由于注射CRF本身即其他试验中因素的干扰。结果表明，注射高剂量的CRF的大鼠对糖球的渴望程度提高到原来的3倍，而低剂量组仅仅增强其对糖球渴望程度。

Nucleus accumbens CRF increases cue-triggered motivation for sucrose reward: paradoxical positive incentive effects in stress?
(Susana Pecina , Jay Schulkin , Kent C Berridge. BMC Biology 2006, 4:8 doi:10.1186/1741-7007-4-8. Published 13 April 2006 )
Abstract (provisional)
Background
    Corticotropin-releasing factor (CRF) is typically considered to mediate aversive aspects of stress, fear and anxiety. However, CRF release in the brain is also elicited by natural rewards and incentive cues, raising the possibility that some CRF systems in the brain mediate an independent function of positive incentive motivation, such as amplifying incentive salience. Here we asked whether activation of a limbic CRF subsystem magnifies the increase in positive motivation for reward elicited by incentive cues previously associated with that reward, in a way that might exacerbate cue-triggered binge pursuit of food or other incentives? We assessed the impact of CRF microinjections into the medial shell of nucleus accumbens using a pure incentive version of Pavlovian-Instrumental transfer, a measure specifically sensitive to the incentive salience of reward cues (which it separates from influences of aversive stress, stress reduction, frustration and other traditional explanations for stress-increased behavior). Rats were first trained to press one of two levers to obtain sucrose pellets, and then separately conditioned to associate a Pavlovian cue with free sucrose pellets. On test days, rats received microinjections of vehicle, CRF (250 or 500 ng/0.2 ul) or amphetamine (20 ug/0.2 ul). Lever pressing was assessed in the presence or absence of the Pavlovian cues during a half-hour test.

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