Dept of VCAPP and Programs in Neuroscience, Washington State University, Pullman, WA 99164-6520, United States.
Physiol Behav. 2011 Nov 30;105(1):94-9. doi: 10.1016/j.physbeh.2011.02.042. Epub 2011 Mar 5.
Glutamate is the neurotransmitter responsible for fast excitatory transmission from vagal afferents to second order neurons in the NTS. Antagonism of NMDA-type glutamate receptors in the NTS increases food intake and attenuates reduction of food intake by vagally mediated satiation signals, such as cholecystokinin. Although, the cellular location(s) of NMDA receptors that participate in satiation is uncertain, recent findings suggest that attenuation of satiation by NMDA receptor antagonists is due, at least in part, to their action on primary vagal afferents themselves. While evidence is accumulating that NMDA receptors located on vagal afferent endings in the hindbrain are involved in control of food intake, there also is preliminary evidence that peripheral NMDA receptors also may influence vagal control of food intake. Hence, NMDA receptor expression on central and perhaps peripheral vagal afferent endings could provide a parsimonious mechanism for modulation of satiation signals by endogenously released glutamate.
谷氨酸是负责从迷走传入神经到 NTS 中的二级神经元的快速兴奋传递的神经递质。NTS 中的 NMDA 型谷氨酸受体拮抗剂增加食物摄入，并减弱迷走介导的饱食信号（如胆囊收缩素）对食物摄入的减少。尽管 NMDA 受体参与饱食的细胞位置尚不确定，但最近的研究结果表明，NMDA 受体拮抗剂对饱食的抑制作用至少部分是由于它们对初级迷走传入纤维本身的作用。虽然有越来越多的证据表明，位于后脑迷走传入末梢的 NMDA 受体参与了食物摄入的控制，但也有初步证据表明，外周 NMDA 受体也可能影响迷走神经对食物摄入的控制。因此，中央和外周迷走传入末梢 NMDA 受体的表达可能为内源性释放的谷氨酸对饱食信号的调制提供了一个简约的机制。
