Interpreting functional imaging studies in terms of neurotransmitter cycling.
Interpreting functional imaging studies in terms of neurotransmitter cycling.
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从神经递质循环角度解释功能成像研究。
DOI：
10.1073/pnas.95.20.11993
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发表时间：
1998
影响因子：
11.1
通讯作者：
Rothman,DL
中科院分区：
文献类型：
--
作者：
Shulman,RG;Rothman,DL
功能成像实验，特别是正电子发射断层扫描和功能磁共振成像，可以从心理学角度或神经科学的基础上进行分析。在通常的心理学解释中，刺激被设计用来激活由认知心理学识别的特定心理过程，然后在功能成像实验中被信号定位。另一种方法是根据负责信号的神经生物学过程来分析实验。最近对大鼠和人脑中谷氨酸-谷氨酰胺神经递质循环的体内13c核磁共振测量有助于从神经生物学过程的角度对功能成像数据进行神经科学解释，因为神经递质通量的增加与葡萄糖氧化速率的增加呈1:1的化学计量关系。由于功能成像信号依赖于脑能量消耗，因此可以在信号(S)与谷氨酸-谷氨酰胺神经递质循环的特定神经化学脑神经递质活性(N)之间建立定量关系。提出的神经元活动的定量对功能成像实验的心理设计和解释具有重要意义。在功能成像实验中对静止状态下神经递质循环通量的测量表明，执行认知任务和感觉刺激只会增加10-20%的神经递质循环。因此，不能假设参考状态活动可以忽略不计，也不能假设它们在刺激期间是恒定的。
Functional imaging experiments, in particular positron-emission tomography and functional magnetic resonance imaging, can be analyzed either in psychological terms or on the basis of neuroscience. In the usual psychological interpretation, stimulations are designed to activate specific mental processes identified by cognitive psychology, which are then localized by the signals in functional imaging experiments. An alternate approach would be to analyze experiments in terms of the neurobiological processes responsible for the signals. Recentin vivo13C NMR measurements of the glutamate-to-glutamine neurotransmitter cycling in rat and human brains facilitate a neuroscientific interpretation of functional imaging data in terms of neurobiological processes since incremental neurotransmitter flux showed a 1:1 stoichiometry with the incremental rate of glucose oxidation. Because functional imaging signals depend on brain energy consumption, a quantitative relationship can be established between the signal (S) and the specific neurochemical cerebral neurotransmitter activity (N) of glutamate-to-glutamine neurotransmitter cycling. The quantitation of neuronal activity proposed has implications for the psychological design and interpretation of functional imaging experiments. Measurements of the neurotransmitter cycling flux at rest in functional imaging experiments suggest that performing cognitive tasks and sensory stimulations increases neurotransmitter cycling by only 10–20%. Therefore it cannot be assumed that reference state activities are negligible, nor that they are constant during stimulation.