Blancas A, González-García S D, Rodríguez K, Escobar C
Departamento de Anatomía, Facultad de Medicina, UNAM, Ciudad Universitaria 3000, México DF 04510, Mexico.
Departamento de Anatomía, Facultad de Medicina, UNAM, Ciudad Universitaria 3000, México DF 04510, Mexico.
Neuroscience. 2014 Dec 5;281:44-53. doi: 10.1016/j.neuroscience.2014.09.036. Epub 2014 Sep 27.
Scheduled and restricted access to a palatable snack, i.e. chocolate, elicits a brief and strong anticipatory activation and entrains brain areas related with reward and motivation. This behavioral and neuronal activation persists for more than 7days when this protocol is interrupted, suggesting the participation of a time-keeping system. The process that initiates this anticipation may provide a further understanding of the time-keeping system underlying palatable food entrainment. The aim of this study was to analyze how this entraining protocol starts and to dissect neuronal structures that initiate a chocolate-entrained activation. We assessed the development of anticipation of 5g of chocolate during the first 8days of the entrainment protocol. General activity of control and chocolate-entrained rats was continuously monitored with movement sensors. Moreover, motivation to obtain the chocolate was assessed by measuring approaches and interaction responses toward a wire-mesh box containing chocolate. Neuronal activation was determined with c-Fos in reward-related brain areas. We report a progressive increase in the interaction with a box to obtain chocolate parallel to a progressive neuronal activation. A significant anticipatory activation was observed in the prefrontal cortex on day 3 of entrainment and in the nucleus accumbens on day 5, while the arcuate nucleus and pyriform cortex reached significant activation on day 8. The gradual response observed with this protocol indicates that anticipation of a rewarding food requires repetitive and predictable experiences in order to acquire a temporal estimation. We also confirm that anticipation of palatable food involves diverse brain regions.
对美味零食（即巧克力）进行定时且受限的获取，会引发短暂而强烈的预期激活，并使与奖励和动机相关的脑区同步激活。当此方案中断时，这种行为和神经元激活会持续超过7天，这表明存在一个计时系统参与其中。引发这种预期的过程可能会进一步加深我们对美味食物同步背后计时系统的理解。本研究的目的是分析这种同步方案是如何启动的，并剖析引发巧克力同步激活的神经元结构。我们评估了在同步方案的前8天中对5克巧克力的预期发展情况。使用运动传感器持续监测对照大鼠和巧克力同步大鼠的一般活动。此外，通过测量对装有巧克力的铁丝网箱的接近和互动反应来评估获取巧克力的动机。用c-Fos测定奖励相关脑区的神经元激活情况。我们报告称，与获取巧克力的箱子的互动逐渐增加，同时神经元也逐渐激活。在同步的第3天，前额叶皮质观察到显著的预期激活，在第5天伏隔核观察到显著激活，而在第8天弓状核和梨状皮质达到显著激活。用此方案观察到的逐渐反应表明，对奖励性食物的预期需要重复且可预测的体验，以便获得时间估计。我们还证实，对美味食物的预期涉及多个脑区。
