Localization of two high‐threshold potassium channel subunits in the rat central auditory system

@article{Li2001LocalizationOT,
 title={Localization of two high‐threshold potassium channel subunits in the rat central auditory system},
 author={Wenge Li and Leonard K. Kaczmarek and Teresa M. Perney},
 journal={Journal of Comparative Neurology},
 year={2001},
 volume={437},
 url={https://api.semanticscholar.org/CorpusID:22217005}
}
Results suggest that KV3.3 channels may be the dominant Kv3 subfamily member expressed in brainstem auditory neurons and that, in some auditory neurons, Kv1.1 and Kv2.3 may coassemble to form functional channels.

145 Citations

Localization of Kv1.3 channels in presynaptic terminals of brainstem auditory neurons
The finding of a tonotopic gradient in presynaptic terminals suggests that Kv1.3 may regulate neurotransmitter release differentially in neurons that respond to different frequencies of sound.

Expression of the Kv1.1 ion channel subunit in the auditory brainstem of the big brown bat, Eptesicus fuscus
Neurons with high levels of Kv1.1 were differentially distributed in the intermediate nucleus of the lateral lemniscus and in the inferior colliculus, suggesting that these structures contain functionally distinct cell populations, some of which may be involved in high‐precision temporal processing.

Physiological modulators of Kv3.1 channels adjust firing patterns of auditory brain stem neurons.
The results suggest that pharmaceutical modulation of Kv3.1 currents represents a novel avenue for manipulation of neuronal excitability and has the potential for therapeutic benefit in the treatment of hearing disorders.

Modulation of the Kv3.1b Potassium Channel Isoform Adjusts the Fidelity of the Firing Pattern of Auditory Neurons
Modulation of Kv3.1 by phosphorylation allows auditory neurons to tune their responses to different patterns of sensory stimulation, and suggests that modulation of K v3.2 current is sufficient to increase the accuracy of response at intermediate frequencies while impairing responses at high frequencies.

Tuning Neuronal Potassium Channels to the Auditory Environment
The expression of Kv3 family voltage-dependent potassium channels, which allow neurons to fire many hundreds of times per second, may maximize the accuracy of information transfer through brainstem nuclei in different auditory environments, and may contribute to the learning of auditory discrimination tasks.

Voltage-gated Potassium Channel (Kv) Subunits Expressed in the Rat Cochlear Nucleus
Using immunohistochemistry in free-floating slices, the distribution of seven Kv subunits was described in the rat CN and it was found that neither giant nor pyramidal cells were uniform in terms of their Kv expression patterns.

Quantitative analysis of neurons with Kv3 potassium channel subunits, Kv3.1b and Kv3.2, in macaque primary visual cortex
Data indicate that, within the population of cortical neurons, a broader population of neurons, encompassing cells of a wider range of morphological classes may be capable of sustaining high‐frequency firing in macaque V1.

Acoustic environment determines phosphorylation state of the Kv3.1 potassium channel in auditory neurons
Using computational modeling, it is shown that high amounts of Kv3.1 current decrease the timing accuracy of action potentials but enable neurons to follow high-frequency stimuli, indicating that the intrinsic electrical properties of auditory neurons are rapidly modified to adjust to the ambient acoustic environment.
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94 References

Localization of a high threshold potassium channel in the rat cochlear nucleus
The pattern of immunolabeling revealed that the Kv3.1 protein is distributed along the soma, proximal dendrites, unmyelinated axons, and axon terminals of stained neurons, which enhances the ability of a model cell with some of the features of bushy cells to follow high frequency input with temporal precision.

Contribution of the Kv3.1 potassium channel to high‐frequency firing in mouse auditory neurones
Analysis of patch‐clamp, in situ hybridization and computer simulation techniques concludes that in mouse MNTB neurones the Kv3.1 channel contributes to the ability of these cells to lock their firing to high‐frequency inputs.

Depolarization Selectively Increases the Expression of the Kv3.1 Potassium Channel in Developing Inferior Colliculus Neurons
Depolarization and calcium influx may alter the excitability of immature inferior colliculus neurons by selectively increasing the levels of a Kv3.1-like potassium current, when expressed heterologously.

Expression of the Kv3.1 Potassium Channel in the Avian Auditory Brainstem
The Shaw-like potassium channel Kv3.1, a delayed rectifier with a high threshold of activation, is expressed in the time coding nuclei of the bird auditory brainstem, and its presynaptic localization may be a specialization for enabling neurons in owl NM to transmit high-frequency temporal information with little jitter.

Impaired Fast-Spiking, Suppressed Cortical Inhibition, and Increased Susceptibility to Seizures in Mice Lacking Kv3.2 K+ Channel Proteins
It is found that Kv3.2 −/− mice showed specific alterations in their cortical EEG patterns and an increased susceptibility to epileptic seizures consistent with an impairment of cortical inhibitory mechanisms, suggesting that normal cortical operations depend on the ability of inhibitory interneurons to generate high-frequency firing.

Kv3.1-Kv3.2 channels underlie a high-voltage-activating component of the delayed rectifier K+ current in projecting neurons from the globus pallidus.
These results suggest that the electrophysiological properties of native channels containing Kv3.1 and KV3.2 proteins in pallidal neurons are not significantly affected by factors such as associated subunits or postranslational modifications that result in channels having different properties in heterologous expression systems and native neurons.

Contributions of Kv3 Channels to Neuronal Excitability
Experimental evidence has now become available showing that Kv3.2 channels play critical roles in the generation of fast‐spiking properties in cortical GABAergic interneurons and to help regulate the fidelity of synaptic transmission.

The potassium channel subunit KV3.1b is localized to somatic and axonal membranes of specific populations of CNS neurons
Site- specific antibodies were utilized to characterize the distribution of KV3.1b, a subunit of voltage-gated K+ channels in CNS neurons, which is consistent with a role in the modulation of action potentials.

Identification of the Kv2.1 K+ Channel as a Major Component of the Delayed Rectifier K+ Current in Rat Hippocampal Neurons
Together these studies show that Kv2.1, which is expressed at high levels in most mammalian central neurons, is a major contributor to the delayed rectifier K+ current in hippocampal neurons and that the KC antibody is a powerful tool for the elucidation of the role of the Kv 2.1 K+ channel in regulating neuronal excitability.
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