当前位置： SCI文献检索 > CHRONOBIOLOGY INTERNATIONAL期刊下所有文献 > D1 dopamine receptors modulate cone ON bipolar cell Nav channels to control daily rhythms in photopic vision.

D1 dopamine receptors modulate cone ON bipolar cell Nav channels to control daily rhythms in photopic vision.

Abstract：

:In amphibians, voltage-gated sodium (Nav) channels in cone ON bipolar cells (ON-CBC) amplify cone signals in the dark and in mesopic background light. However, during light adaptation, dopamine, acting through D1 receptors (D1R), suppresses Nav channels and therefore act as a gain control mechanism. Curiously in rodents, Nav channel contributions to the ON-CBC-generated light-adapted electroretinogram (ERG) b-wave appear to exist even in fully light-adapted conditions. We sought to determine how rodent ON-CBC Nav channels are regulated by dopamine via D1R during light adaptation and during the circadian cycle. We first tested the sensitivity of Nav channels in mouse ON-CBCs to the modulation by dopamine via D1Rs. Although light-adaptation had little effect on Nav channel contributions to the b-wave, these channels were found to be modulated by D1Rs. We pharmacologically isolated the cone to ON-CBC circuit in fully light-adapted retinas to confirm these results. Retinal dopamine release following light adaptation has been previously shown to be increased in mice during circadian night. We first show that circadian fluctuations in ON-CBC function are suppressed in dark-adapted retinas, indicating that circadian fluctuations are a function of light adaptation. Secondly, we show that at night the mouse retina behaves similarly to those of frogs and salamanders with a gain control mechanism utilizing D1R modulation of Nav channels to suppress ON-CBC light responses in light-adapted conditions during circadian night. Taken together, these results suggest that circadian control of ON-CBC function contains an initial phase after approximately 18-30 h of dark adaptation, leading to substantial changes in b-wave amplitude after a relatively short time in free run which are dependent on D1R modulation of Nav channels.

journal_name

Chronobiol Int

journal_title

Chronobiology international

authors

Smith BJ,Côté PD,Tremblay F

doi

10.3109/07420528.2014.951054

subject

Has Abstract

pub_date

2015-02-01 00:00:00

pages

48-58

issue

eissn

0742-0528

issn

1525-6073

journal_volume

pub_type

杂志文章

在线工具

D1 dopamine receptors modulate cone ON bipolar cell Nav channels to control daily rhythms in photopic vision.