Rod Vision Is Controlled by Dopamine-Dependent Sensitization of Rod Bipolar Cells by GABA

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• 作者：Rolf Herrmann¹ ; Stephanie  ; J. Heflin³ ; Timothy Hammond¹ ; Bowa Lee¹ ; Jing Wang⁴ ; Raul  ; R. Gainetdinov² ;   ; ⁵ ; Marc  ; G. Caron² ; Erika  ; D. Eggers⁶ ; Laura  ; J. Frishman⁴ ;   ; ^{lfrishman@uh.edu} ; Maureen  ; A. McCall³ ;   ; ^{mo.mccall@louisville.edu} ; Vadim  ; Y. Arshavsky¹ ;   ; ^{vadim.arshavsky@duke.edu}
• 刊名：Neuron
• 出版年：2011
• 出版时间：6 October 2011
• 年：2011
• 卷：72
• 期：1
• 页码：101-110
• 全文大小：1362 K

文摘

Summary

Dark and light adaptation of retinal neurons allow our vision to operate over an enormous light intensity range. Here we report a mechanism that controls the light sensitivity and operational range of rod-driven bipolar cells that mediate dim-light vision. Our data indicate that the light responses of these cells are enhanced by sustained chloride currents via GABA_C receptor channels. This sensitizing GABAergic input is controlled by dopamine D1 receptors, with horizontal cells serving as a plausible source of GABA release. Our findings expand the role of dopamine in vision from its well-established function of suppressing rod-driven signals in bright light to enhancing the same signals under dim illumination. They further reveal a role for GABA in sensitizing the circuitry for dim-light vision, thereby complementing GABA's traditional role in providing dynamic feedforward and feedback inhibition in the retina.