Temperature Dependence of the Inward Rectifier K+ Channel Gating in Guinea-Pig Ventricular Cells.

Mitsuiye, Tamotsu; Shinagawa, Yasuko; Noma, Akinori

doi:10.2170/jjphysiol.47.73

Cited by 12 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent with this, the warming-triggered outward current was blocked by extracellular Ba 2 + , a blocker of Kir channels. Another study of Kir in dopaminergic neurons of the mouse olfactory bulb has shown that Kir is mildly temperature-sensitive, with a Q10 of~1.22 [64], similar to Kir recorded in cardiac ventricular cells (1.28) [65]. An ATP-sensitive Kir channel was reported to have a Q10 of 1.38 [66] while recordings of another ATP-sensitive K + current in cardiac myocytes had a similar Q10 at the 20-30˚C range but a higher Q10 (2.3) at temperatures between 10-20˚C.…”

Section: Plos Onementioning

confidence: 62%

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Hook

2020

PLoS ONE

View full text Add to dashboard Cite

Numerous neuronal properties including the synaptic vesicle release process, neurotransmitter receptor complement, and postsynaptic ion channels are involved in transforming synaptic inputs into postsynaptic spiking. Temperature is a significant influencer of neuronal function and synaptic integration. Changing temperature can affect neuronal physiology in a diversity of ways depending on how it affects different members of the cell's ion channel complement. Temperature's effects on neuronal function are critical for pathological states such as fever, which can trigger seizure activity, but are also important in interpreting and comparing results of experiments conducted at room vs physiological temperature. The goal of this study was to examine the influence of temperature on synaptic properties and ion channel function in thalamocortical (TC) relay neurons in acute brain slices of the dorsal lateral geniculate nucleus, a key synaptic target of retinal ganglion cells in the thalamus. Warming the superfusate in patch clamp experiments with acutely-prepared brain slices led to an overall inhibition of synaptically-driven spiking behavior in TC neurons in response to a retinal ganglion cell spike train. Further study revealed that this was associated with an increase in presynaptic synaptic vesicle release probability and synaptic depression and altered passive and active membrane properties. Additionally, warming the superfusate triggered activation of an inwardly rectifying potassium current and altered the voltage-dependence of voltage-gated Na + currents and T-type calcium currents. This study highlights the importance of careful temperature control in ex vivo physiological experiments and illustrates how numerous properties such as synaptic inputs, active conductances, and passive membrane properties converge to determine spike output.

show abstract

Section: Plos Onementioning

confidence: 62%

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Hook

2020

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…In guinea pig ventricular cells, the conductance of inward rectifier potassium currents decreased by lowering the temperature with a Q 10 of 1.28 (whole cell recordings), or 1.41 (single channel recordings) between 20℃ and 30℃ [13]. The channel open probability was scarcely affected by temperature, however, the time constant of open-time histogram progressively increased as the temperature was lowered and the configuration of closed-time distribution was markedly modified by changing the temperature.…”

Section: Discussionmentioning

confidence: 99%

Temperature Enhances Activation and Inactivation Kinetics of Potassium Currents in Inner Hair Cells Isolated from Guinea-Pig Cochlea

Kimitsuki

Komune

2013

Clin Exp Otorhinolaryngol

View full text Add to dashboard Cite

ObjectivesUntil recently, most patch-clamp recordings in inner hair cells (IHCs) have been performed at room temperature. The results acquired at room temperature should be corrected if they are to be related to in vivo findings. However, the temperature dependency to ion channels in IHCs is unknown. The aim of this study was to investigate the effect of temperature on the potassium currents in IHCs.MethodsIHCs were isolated from a mature guinea-pig cochlea and potassium currents were recorded at room temperature (around 25℃) and physiological temperatures (35℃-37℃).ResultsIHCs showed outwardly rectifying currents in response to depolarizing voltage pulses, with only a slight inward current when hyperpolarized. The amplitude of both outward and inward currents demonstrated no temperature dependency, however, activation and inactivation rates were faster at 36℃ than at room temperature. Half-time for activation was shorter at 36℃ than at room temperature at membrane potentials of -10, +10, +20, +30, and +40 mV. Q10 for the activation rate was 1.83. The inactivation time constant in outward tetraethylammonium-sensitive potassium currents was much smaller at 36℃ than at room temperature between the membrane potentials of -20 and +60 mV. Q10 for the inactivation time constant was 3.19.ConclusionThe results of this study suggest that the amplitude of potassium currents in IHCs showed no temperature dependence either in outward or inward-going currents, however, activation and inactivation accelerated at physiological temperatures.

show abstract

“…The relative activity of glial KIR channels and neuronal/glial Na ϩ /K ϩ -pump in CA3 rat hippocampus at body temperature cannot be accurately determined at the present time because the specific Q10s of these two K ϩ -buffering systems have yet to be measured. However, at body temperature the Q10 of other inwardly rectifying K ϩ currents is in the 1.6/2.4 range (Caffier and Shvinka 1986;McLarnon et al 1993;Mitsuiye et al 1997). Similarly, the Q10 for the Na ϩ /K ϩ -pump is in the 1.2/2.1 range (Glitsch and Pusch 1984;Nakamura et al 1999;Sakai et al 1996).…”

Section: Glial Kir Channels Lower K ϩ Baseline Do Not Affect the Ratmentioning

confidence: 99%

Differential Role of KIR Channel and Na⁺/K⁺-Pump in the Regulation of Extracellular K⁺ in Rat Hippocampus

D’Ambrosio

Gordon

Winn

2002

Journal of Neurophysiology

216

148

View full text Add to dashboard Cite

Little information is available on the specific roles of different cellular mechanisms involved in extracellular K(+) homeostasis during neuronal activity in situ. These studies have been hampered by the lack of an adequate experimental paradigm able to separate K(+)-buffering activity from the superimposed extrusion of K(+) from variably active neurons. We have devised a new protocol that allows for such an analysis. We used paired field- and K(+)-selective microelectrode recordings from CA3 stratum pyramidale during maximal Schaffer collateral stimulation in the presence of excitatory synapse blockade to evoke purely antidromic spikes in CA3. Under these conditions of controlled neuronal firing, we studied the [K(+)]o baseline during 0.05 Hz stimulation, and the accumulation and rate of recovery of extracellular K(+) at higher frequency stimulation (1-3 Hz). In the first set of experiments, we showed that neuronal hyperpolarization by extracellular application of ZD7288 (11 microM), a selective blocker of neuronal I(h) currents, does not affect the dynamics of extracellular K(+). This indicates that the K(+) dynamics evoked by controlled pyramidal cell firing do not depend on neuronal membrane potential, but only on the balance between K(+) extruded by firing neurons and K(+) buffered by neuronal and glial mechanisms. In the second set of experiments, we showed that di-hydro-ouabain (5 microM), a selective blocker of the Na(+)/K(+)-pump, yields an elevation of baseline [K(+)]o and abolishes the K(+) recovery during higher frequency stimulation and its undershoot during the ensuing period. In the third set of experiments, we showed that Ba(2+) (200 microM), a selective blocker of inwardly rectifying K(+) channels (KIR), does not affect the posttetanus rate of recovery of [K(+)]o, nor does it affect the rate of K(+) recovery during high-frequency stimulation. It does, however, cause an elevation of baseline [K(+)]o and an increase in the amplitude of the ensuing undershoot. We show for the first time that it is possible to differentiate the specific roles of Na(+)/K(+)-pump and KIR channels in buffering extracellular K(+). Neuronal and glial Na(+)/K(+)-pumps are involved in setting baseline [K(+)]o levels, determining the rate of its recovery during sustained high-frequency firing, and determining its postactivity undershoot. Conversely, glial KIR channels are involved in the regulation of baseline levels of K(+), and in decreasing the amplitude of the postactivity [K(+)]o undershoot, but do not affect the rate of K(+) clearance during neuronal firing. The results presented provide new insights into the specific physiological role of glial KIR channels in extracellular K(+) homeostasis.

show abstract

Temperature Dependence of the Inward Rectifier K+ Channel Gating in Guinea-Pig Ventricular Cells.

Cited by 12 publications

References 0 publications

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Temperature Enhances Activation and Inactivation Kinetics of Potassium Currents in Inner Hair Cells Isolated from Guinea-Pig Cochlea

Differential Role of KIR Channel and Na⁺/K⁺-Pump in the Regulation of Extracellular K⁺ in Rat Hippocampus

Contact Info

Product

Resources

About

Temperature Dependence of the Inward Rectifier K+ Channel Gating in Guinea-Pig Ventricular Cells.

Cited by 12 publications

References 0 publications

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Temperature effects on synaptic transmission and neuronal function in the visual thalamus

Temperature Enhances Activation and Inactivation Kinetics of Potassium Currents in Inner Hair Cells Isolated from Guinea-Pig Cochlea

Differential Role of KIR Channel and Na+/K+-Pump in the Regulation of Extracellular K+ in Rat Hippocampus

Contact Info

Product

Resources

About

Differential Role of KIR Channel and Na⁺/K⁺-Pump in the Regulation of Extracellular K⁺ in Rat Hippocampus