TMEM16C belongs to the TMEM16 family, which includes the Ca(2+)-activated Cl(-) channels TMEM16A and TMEM16B and a small-conductance, Ca(2+)-activated, nonselective cation channel (SCAN), TMEM16F. We found that in rat dorsal root ganglia (DRG) TMEM16C was expressed mainly in the IB4-positive, non-peptidergic nociceptors that also express the sodium-activated potassium (K(Na)) channel Slack. Together these channel proteins promote K(Na) channel activity and dampen neuronal excitability. DRG from TMEM16C knockout rats had diminished Slack expression, broadened action potentials and increased excitability. Moreover, the TMEM16C knockout rats, as well as rats with Slack knockdown by intrathecal injection of short interfering RNA, exhibited increased thermal and mechanical sensitivity. Experiments involving heterologous expression in HEK293 cells further showed that TMEM16C modulated the single-channel activity of Slack channels and increased its sodium sensitivity. Our study thus reveals that TMEM16C enhances K(Na) channel activity in DRG neurons and regulates the processing of pain messages.
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http://dx.doi.org/10.1038/nn.3468 | DOI Listing |
Elife
October 2024
Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, United States.
Cell Rep
March 2024
Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA. Electronic address:
The KCNT1 gene encodes the sodium-activated potassium channel Slack (KCNT1, K1.1), a regulator of neuronal excitability. Gain-of-function mutations in humans cause cortical network hyperexcitability, seizures, and severe intellectual disability.
View Article and Find Full Text PDFMol Neurobiol
April 2024
Department of Pharmacology, Yale School of Medicine, New Haven, CT, 06520, USA.
The ability of monkeys and rats to carry out spatial working memory tasks has been shown to depend on the persistent firing of pyramidal cells in the prefrontal cortex (PFC), arising from recurrent excitatory connections on dendritic spines. These spines express hyperpolarization-activated cyclic nucleotide-gated (HCN) channels whose open state is increased by cAMP signaling, and which markedly alter PFC network connectivity and neuronal firing. In traditional neural circuits, activation of these non-selective cation channels leads to neuronal depolarization and increased firing rate.
View Article and Find Full Text PDFbioRxiv
August 2024
Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA.
More than twenty recurrent missense gain-of-function (GOF) mutations have been identified in the sodium-activated potassium (K) channel gene in patients with severe developmental and epileptic encephalopathies (DEEs), most of which are resistant to current therapies. Defining the neuron types most vulnerable to KCNT1 GOF will advance our understanding of disease mechanisms and provide refined targets for precision therapy efforts. Here, we assessed the effects of heterozygous expression of a GOF variant (Y777H) on K currents and neuronal physiology among cortical glutamatergic and GABAergic neurons in mice, including those expressing vasoactive intestinal polypeptide (VIP), somatostatin (SST), and parvalbumin (PV), to identify and model the pathogenic mechanisms of autosomal dominant GOF variants in DEEs.
View Article and Find Full Text PDFThe ability of monkeys and rats to carry out spatial working memory tasks has been shown to depend on the persistent firing of pyramidal cells in the prefrontal cortex (PFC), arising from recurrent excitatory connections on dendritic spines. These spines express hyperpolarization-activated cyclic nucleotide-gated (HCN) channels whose open state is increased by cAMP signaling, and which markedly alter PFC network connectivity and neuronal firing. In traditional neural circuits, activation of these non-selective cation channels leads to neuronal depolarization and increased firing rate.
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