Department of Neuroscience, Yale University School of Medicine, New Haven, CT06510, USA.
Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA.
Cereb Cortex. 2018 Apr 1;28(4):1458-1471. doi: 10.1093/cercor/bhx357.
Neurons in primary visual cortex (V1) are more resilient than those in dorsolateral prefrontal cortex (dlPFC) in aging, schizophrenia and Alzheimer's disease. The current study compared glutamate and neuromodulatory actions in macaque V1 to those in dlPFC, and found striking regional differences. V1 neuronal firing to visual stimuli depended on AMPA receptors, with subtle NMDA receptor contributions, while dlPFC depends primarily on NMDA receptors. Neuromodulatory actions also differed between regions. In V1, cAMP signaling increased neuronal firing, and the phosphodiesterase PDE4A was positioned to regulate cAMP effects on glutamate release from axons. HCN channels in V1 were classically located on distal dendrites, and enhanced cell firing. These data contrast with dlPFC, where PDE4A and HCN channels are concentrated in thin spines, and cAMP-HCN signaling gates inputs and weakens firing. These regional differences may explain why V1 neurons are more resilient than dlPFC neurons to the challenges of age and disease.
初级视觉皮层（V1）中的神经元比背外侧前额叶皮层（dlPFC）中的神经元在衰老、精神分裂症和阿尔茨海默病中更具弹性。本研究比较了猕猴 V1 和 dlPFC 中的谷氨酸和神经调质作用，发现了明显的区域差异。V1 神经元对视觉刺激的反应依赖于 AMPA 受体，而 NMDA 受体的贡献较小，而 dlPFC 主要依赖于 NMDA 受体。区域之间的神经调质作用也存在差异。在 V1 中，cAMP 信号增加神经元的放电，而磷酸二酯酶 PDE4A 的位置可以调节 cAMP 对来自轴突的谷氨酸释放的影响。V1 中的 HCN 通道通常位于远端树突上，并增强细胞放电。这些数据与 dlPFC 形成对比，在 dlPFC 中，PDE4A 和 HCN 通道集中在薄的棘突上，cAMP-HCN 信号传导门控输入并减弱放电。这些区域差异可能解释了为什么 V1 神经元比 dlPFC 神经元更能抵抗年龄和疾病的挑战。
