Intrinsic physiological properties of the five types of mouse ganglion-cell photoreceptors
Intrinsic physiological properties of the five types of mouse ganglion-cell photoreceptors
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DOI：
10.1152/jn.00579.2012
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发表时间：
2013-04-01
影响因子：
2.5
通讯作者：
Wong, Kwoon Y.
中科院分区：
文献类型：
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作者：
Hu, Caiping;Hill, DiJon D.;Wong, Kwoon Y.
胡C，希尔DD，黄KY。五种小鼠神经节细胞光感受器的内在生理特性。J Neurophysiol 109：1876-1889，2013.首次发表于2013年1月23日; doi：10.1152/jn.00579.2012.-在哺乳动物视网膜中，一些神经节细胞表达黑视素色素，并作为光感受器发挥功能。这些内在光敏视网膜神经节细胞（ipRGC），M1-M5，已在小鼠中确定的五种形态类型。而M1专门用于非图像形成视觉功能，并驱动瞳孔光反射和昼夜光诱导等行为，其他类型似乎有助于图像形成以及非图像形成视觉。最近的工作已经开始揭示一些ipRGC类型之间的生理多样性，包括光敏性、放电速率和膜电阻的差异。为了进一步了解这些神经元的功能差异，我们对所有五种形态类型的电生理特性进行了全面的调查。与其他类型相比，M1细胞的膜电阻最高、膜时间常数最长、峰电位频率最低、动作电位最宽、正峰电位阈值最高、超极化激活内向整流电流引起的“下垂”反应最小、电压门控性K+电流对膜电位的影响最大。M4和M5在大多数这些措施的频谱的另一端，而M2和M3往往在这个频谱的中间。此外，M1和M2细胞比M3-M5产生更多样化的电压门控性Ca 2+电流。总之，M1细胞在大多数方面与所有其他ipRGC显著不同，可能反映了非成像视觉的独特生理要求。此外，非M1 ipRGC是电生理异质性的，暗示这些细胞在非图像形成视觉和图案视觉中的不同功能作用。
Hu C, Hill DD, Wong KY. Intrinsic physiological properties of the five types of mouse ganglion-cell photoreceptors. J Neurophysiol 109: 1876-1889, 2013. First published January 23, 2013; doi:10.1152/jn.00579.2012.-In the mammalian retina, some ganglion cells express the photopigment melanopsin and function as photoreceptors. Five morphological types of these intrinsically photosensitive retinal ganglion cells (ipRGCs), M1-M5, have been identified in mice. Whereas M1 specializes in non-image-forming visual functions and drives such behaviors as the pupillary light reflex and circadian photoentrainment, the other types appear to contribute to image-forming as well as non-image-forming vision. Recent work has begun to reveal physiological diversity among some of the ipRGC types, including differences in photosensitivity, firing rate, and membrane resistance. To gain further insights into these neurons' functional differences, we conducted a comprehensive survey of the electrophysiological properties of all five morphological types. Compared with the other types, M1 had the highest membrane resistance, longest membrane time constant, lowest spike frequencies, widest action potentials, most positive spike thresholds, smallest hyperpolarization-activated inwardly-rectifying current-induced "sagging" responses to hyperpolarizing currents, and the largest effects of voltage-gated K+ currents on membrane potentials. M4 and M5 were at the other end of the spectrum for most of these measures, while M2 and M3 tended to be in the middle of this spectrum. Additionally, M1 and M2 cells generated more diverse voltage-gated Ca2+ currents than M3-M5. In conclusion, M1 cells are significantly different from all other ipRGCs in most respects, possibly reflecting the unique physiological requirements of non-image-forming vision. Furthermore, the non-M1 ipRGCs are electrophysiologically heterogeneous, implicating these cells' diverse functional roles in both non-image-forming vision and pattern vision.