Training-induced elevations in extracellular lactate in hippocampus and striatum: Dissociations by cognitive strategy and type of reward.
Training-induced elevations in extracellular lactate in hippocampus and striatum: Dissociations by cognitive strategy and type of reward.
复制标题
训练引起的海马和纹状体细胞外乳酸升高：认知策略和奖励类型的分离。
DOI：
10.1016/j.nlm.2016.12.001
复制
发表时间：
2017
影响因子：
2.7
通讯作者：
Korol,DonnaL
中科院分区：
文献类型：
--
作者：
Newman,LoriA;Scavuzzo,ClaireJ;Gold,PaulE;Korol,DonnaL
最近的证据表明，星形胶质细胞将葡萄糖转化为乳酸，乳酸从星形胶质细胞中释放出来，支持学习和记忆。这份报告从多重记忆的角度，使用学习和记忆过程中的实时乳酸测量来测试星形胶质细胞在认知中的作用。用乳酸生物传感器测定大鼠在学习地点(对海马敏感)或反应(对纹状体敏感)版本的T迷宫时，海马区或纹状体的细胞外乳酸水平。在第一个实验中，对大鼠进行位置和反应任务的训练，以确定食物奖励的位置。海马区细胞外乳酸水平在位置训练期间高于喂养对照组，但在反应训练期间没有增加。然而，当大鼠在迷宫的地点或反应版本上进行训练时，纹状体乳酸水平并没有超过对照组。因为食物摄入本身会增加血糖和大脑乳酸水平，所以进食的贡献可能会扰乱大脑乳酸的测量。因此，我们进行了第二个类似的实验，用水作为奖励。当水被用作任务奖励时，乳酸对训练的反应出现了非常不同的模式。首先，提供水本身并不会导致大脑或血液乳酸水平的大幅上升。此外，纹状体的细胞外乳酸水平在反应过程中增加，但在位置学习过程中没有增加，而海马体的细胞外乳酸水平在不同任务中没有差异。这两个实验的发现表明，海马体和纹状体的相对参与不仅与任务有关，还与奖励类型有关。在不同的奖励条件下，海马体和纹状体的不同乳酸反应和反应任务可能反映了与觅食和水有关的行为学限制。
Recent evidence suggests that astrocytes convert glucose to lactate, which is released from the astrocytes and supports learning and memory. This report takes a multiple memory perspective to test the role of astrocytes in cognition using real-time lactate measurements during learning and memory. Extracellular lactate levels in the hippocampus or striatum were determined with lactate biosensors while rats were learning place (hippocampus-sensitive) or response (striatum-sensitive) versions of T-mazes. In the first experiment, rats were trained on the place and response tasks to locate a food reward. Extracellular lactate levels in the hippocampus increased beyond those of feeding controls during place training but not during response training. However, striatal lactate levels did not increase beyond those of controls when rats were trained on either the place or the response version of the maze. Because food ingestion itself increased blood glucose and brain lactate levels, the contribution of feeding may have confounded the brain lactate measures. Therefore, we conducted a second similar experiment using water as the reward. A very different pattern of lactate responses to training emerged when water was used as the task reward. First, provision of water itself did not result in large increases in either brain or blood lactate levels. Moreover, extracellular lactate levels increased in the striatum during response but not place learning, whereas extracellular lactate levels in the hippocampus did not differ across tasks. The findings from the two experiments suggest that the relative engagement of the hippocampus and striatum dissociates not only by task but also by reward type. The divergent lactate responses of the hippocampus and striatum in place and response tasks under different reward conditions may reflect ethological constraints tied to foraging for food and water.