Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity
Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity
复制标题
DOI：
10.1113/jphysiol.2008.164285
复制
发表时间：
2009-04-01
影响因子：
5.5
通讯作者：
Jones, D. A.
中科院分区：
文献类型：
--
作者：
Chambers, E. S.;Bridge, M. W.;Jones, D. A.
运动研究表明，人类口腔中碳水化合物的存在会激活大脑中可以增强运动表现的区域，但这种机制的直接证据有限。本研究的第一个目的是观察用含有葡萄糖和麦芽糊精的溶液漱口，用人造甜味剂伪装，会影响运动表现。第二个目标是使用功能性磁共振成像（fMRI）来识别这些物质激活的大脑区域。在研究1A中，8名经过耐力训练的自行车运动员（（V）超过点（O2 max）60.8 +/- 4.1 ml kg（-1）min（-1））完成了一项周期时间试验（总功= 914 +/- 29 kJ）与含糖精的安慰剂相比，用6.4%葡萄糖溶液漱口时，（分别为60.4 +/- 3.7和61.6 +/- 3.8 min，P = 0.007）。相应的功能磁共振成像研究（研究1B）显示，口服葡萄糖激活了与奖励相关的大脑区域，包括前扣带皮层和纹状体，这些区域对糖精没有反应。在研究2A中，8名经过耐力训练的自行车运动员（（V）超过点（O2 max）57.8 +/- 3.2 ml kg（-1）min（-1））测试了用6.4%麦芽糊精溶液冲洗对运动表现的影响，显示它大大减少了完成周期时间试验的时间（总功= 837 +/- 68 kJ）与人工甜味安慰剂（分别为62.6 +/- 4.7和64.6 +/- 4.9 min，P = 0.012）相比。第二项神经影像学研究（研究2B）比较了皮质对口服麦芽糊精和葡萄糖的反应，揭示了对两种碳水化合物溶液反应的相似脑激活模式，包括大脑/额叶盖、眶额皮质和纹状体区域。结果表明，当碳水化合物存在于口中时，观察到的运动表现的改善可能是由于被认为参与奖励和运动控制的大脑区域的激活。研究结果还表明，可能存在一类迄今为止尚未鉴定的口腔受体，它们对碳水化合物的反应独立于对甜味的反应。
Exercise studies have suggested that the presence of carbohydrate in the human mouth activates regions of the brain that can enhance exercise performance but direct evidence of such a mechanism is limited. The first aim of the present study was to observe how rinsing the mouth with solutions containing glucose and maltodextrin, disguised with artificial sweetener, would affect exercise performance. The second aim was to use functional magnetic resonance imaging (fMRI) to identify the brain regions activated by these substances. In Study 1A, eight endurance-trained cyclists ((V) over dot(O2max) 60.8 +/- 4.1 ml kg(-1) min(-1)) completed a cycle time trial ( total work = 914 +/- 29 kJ) significantly faster when rinsing their mouths with a 6.4% glucose solution compared with a placebo containing saccharin (60.4 +/- 3.7 and 61.6 +/- 3.8 min, respectively, P = 0.007). The corresponding fMRI study (Study 1B) revealed that oral exposure to glucose activated reward-related brain regions, including the anterior cingulate cortex and striatum, which were unresponsive to saccharin. In Study 2A, eight endurance-trained cyclists ((V) over dot(O2max) 57.8 +/- 3.2 ml kg(-1) min(-1)) tested the effect of rinsing with a 6.4% maltodextrin solution on exercise performance, showing it to significantly reduce the time to complete the cycle time trial ( total work = 837 +/- 68 kJ) compared to an artificially sweetened placebo (62.6 +/- 4.7 and 64.6 +/- 4.9 min, respectively, P = 0.012). The second neuroimaging study (Study 2B) compared the cortical response to oral maltodextrin and glucose, revealing a similar pattern of brain activation in response to the two carbohydrate solutions, including areas of the insula/frontal operculum, orbitofrontal cortex and striatum. The results suggest that the improvement in exercise performance that is observed when carbohydrate is present in the mouth may be due to the activation of brain regions believed to be involved in reward and motor control. The findings also suggest that there may be a class of so far unidentified oral receptors that respond to carbohydrate independently of those for sweetness.