Calcium and calcium-dependent chloride currents generate action potentials in solitary cone photoreceptors

Maricq, Andres V.; Korenbrot, Juan I.

doi:10.1016/0896-6273(88)90181-x

Cited by 121 publications

(93 citation statements)

References 40 publications

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“…Transduction mechanisms are faster in cones than in rods, and although cones have been shown to express most of the same channel types as rods, one corresponding to I Kx has not been described (Attwell et al, 1982;Maricq and Korenbrot, 1988;Barnes and Hille, 1989). In preliminary experiments we identified a current similar to I Kx in cones, but found it to be about 4 times smaller (12 ± 3 pA at -30 mV, n = 5) than that in rods.…”

Section: Roles For I Kx In the Rod Response To Lightmentioning

confidence: 81%

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Beech

Barnes

1989

Neuron

102

100

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SummaryIn this study a K + current, I Kx , in isolated salamander rod photoreceptors was characterized and its role in shaping small photovoltages was examined. I Kx is a standing outward current of about 40 pA at -30 mV that deactivates slowly when the cell is hyperpolarized (τ max = 0.25 s). The voltage and time dependence of I Kx are similar to that of M-current, but I Kx can be distinguished from Mcurrent because it is not suppressed by acetylcholine and is "blocked" by external Ba 2+ in a surprising manner: the activation range of I Kx is shifted strongly in the positive direction. Using current-clamp recordings and a computer simulation of the photoresponse, we show that I Kx figures prominently in setting the dark resting potential and accelerates the voltage response to small photocurrents.

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Section: Roles For I Kx In the Rod Response To Lightmentioning

confidence: 81%

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Beech

Barnes

1989

Neuron

102

100

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“…Moreover, single-channel recordings (Rodriguez-Contreras and Yamoah, 2003) of L-type Ca 2+ channels in hair cells reveal clearly that at any test voltage Ba 2+ results in much greater activation of the channel than Ca 2+ does, i.e., the channel has a much higher open probability in Ba 2+ . Barium also fails to activate significantly calcium-dependent channels, including a Ca 2+ -dependent potassium current (Bader et al, 1982;Moriondo et al, 2001) and a Ca 2+ -dependent chloride current (ICl Ca Maricq and Korenbrot, 1988;. Thus, the use of Ba is beneficial because it allows better isolation of I Ca , but it also obscures functionally important interactions between calcium and calcium-dependent channels (see Section 5.1).…”

Section: Impact Of Experimental Conditionsmentioning

confidence: 99%

“…5.1.3. Calcium-dependent chloride channels-One feature of photoreceptor terminals is the presence of a large Ca 2+ -activated Cl − current [I Cl(Ca) ] activated by influx through I Ca (Corey et al, 1984;Maricq and Korenbrot, 1988;Barnes and Hille, 1989;Yagi and MacLeish, 1994;Taylor and Morgans, 1998). Cl − flux through these channels can be substantial.…”

Section: Ionic Modulation Of Calcium Channels: Chloride-reducing the mentioning

confidence: 99%

Synaptic transmission at retinal ribbon synapses

Heidelberger

Thoreson

Witkovsky

2005

Progress in Retinal and Eye Research

209

231

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The molecular organization of ribbon synapses in photoreceptors and ON bipolar cells is reviewed in relation to the process of neurotransmitter release. The interactions between ribbon synapseassociated proteins, synaptic vesicle fusion machinery and the voltage-gated calcium channels that gate transmitter release at ribbon synapses are discussed in relation to the process of synaptic vesicle exocytosis. We describe structural and mechanistic specializations that permit the ON bipolar cell to release transmitter at a much higher rate than the photoreceptor does, under in vivo conditions. We also consider the modulation of exocytosis at photoreceptor synapses, with an emphasis on the regulation of calcium channels.

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“…In the nervous system functional CaCCs are best characterized in neurons with various sensory functions, such as olfactory neurons (Kleene & Gesteland, 1991; Lowe & Gold, 1993), photosensitive rods and cones (Bader et al . 1982; Maricq & Korenbrot, 1988; Barnes & Hille, 1989), taste cells (Taylor & Roper, 1994) and somatosensory neurons (Liu et al . 2010; Cho et al .…”

Section: Introductionmentioning

confidence: 99%

Activation of Ca²⁺‐activated Cl⁻ channel ANO1 by localized Ca²⁺ signals

Jin

Shah

et al. 2014

The Journal of Physiology

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Ca2+‐activated chloride channels (CaCCs) regulate numerous physiological processes including epithelial transport, smooth muscle contraction and sensory processing. Anoctamin‐1 (ANO1, TMEM16A) is a principal CaCC subunit in many cell types, yet our understanding of the mechanisms of ANO1 activation and regulation are only beginning to emerge. Ca2+ sensitivity of ANO1 is rather low and at negative membrane potentials the channel requires several micromoles of intracellular Ca2+ for activation. However, global Ca2+ levels in cells rarely reach such levels and, therefore, there must be mechanisms that focus intracellular Ca2+ transients towards the ANO1 channels. Recent findings indeed indicate that ANO1 channels often co‐localize with sources of intracellular Ca2+ signals. Interestingly, it appears that in many cell types ANO1 is particularly tightly coupled to the Ca2+ release sites of the intracellular Ca2+ stores. Such preferential coupling may represent a general mechanism of ANO1 activation in native tissues.

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Calcium and calcium-dependent chloride currents generate action potentials in solitary cone photoreceptors

Cited by 121 publications

References 40 publications

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Synaptic transmission at retinal ribbon synapses

Activation of Ca²⁺‐activated Cl⁻ channel ANO1 by localized Ca²⁺ signals

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Calcium and calcium-dependent chloride currents generate action potentials in solitary cone photoreceptors

Cited by 121 publications

References 40 publications

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light

Synaptic transmission at retinal ribbon synapses

Activation of Ca2+‐activated Cl− channel ANO1 by localized Ca2+ signals

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Activation of Ca²⁺‐activated Cl⁻ channel ANO1 by localized Ca²⁺ signals