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hcn channel

Zi-Jian Wu, Jie Wang, Wen-Xiu Duan, Chang-Ping Gong, Ling Hu
OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of Heart and Lung meridians on the expression of hyperpolarization-activated cyclic nucleotide gated potassium channel 2 (HCN 2) mRNA and protein in the myocar-dium of the left ventricle in acute myocardial ischemia (AMI) rats, so as to underlying its mechanism in improving ischemic myocardial injury. METHODS: A total of 120 male SD rats were randomly divided into normal control, model, EA-Heart Meridian (HT) and EA-Lung Meridian (LU) groups ( n =30 rats in each group)...
March 25, 2018: Zhen Ci Yan Jiu, Acupuncture Research
Jie Gao, Zhiqiang Hu, Liwei Shi, Na Li, Yeling Ouyang, Shaofang Shu, Shanglong Yao, Xiangdong Chen
It is widely accepted that the induction dose of anesthetics is higher in infants than in adults, although the relevant molecular mechanism remains elusive. We previously showed neuronal hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels contribute to hypnotic actions of propofol and ketamine. Interestingly, the expression of HCN channels in neocortex significantly changes during postnatal periods. Thus, we postulated that changes in HCN channels expression might contribute to sensitivity to intravenous anesthetics...
February 27, 2018: Oncotarget
Anchal Gahlaut, Manikandan Paranjothy
Formamide (NH2 CHO), being the simplest organic molecule containing an amide functional group, serves as a prototype to study protein and peptide chemistry. Formamide has been found in Comets and interstellar media and its decomposition results in smaller molecules such as NH3 , CO, HCN, HNCO, etc. These smaller molecules are considered to have been potential precursors for the formation of complex biological molecules, such as nucleic acids and nucleobases, in the early Earth. Several experimental and theoretical investigations of formamide decomposition have been reported in the literature...
March 14, 2018: Physical Chemistry Chemical Physics: PCCP
Wenqin Hu, Bruce P Bean
Voltage-dependent conductances not only drive action potentials but also help regulate neuronal resting potential. We found differential regulation of resting potential in the proximal axon of layer 5 pyramidal neurons compared to the soma. Axonal resting potential was more negative than the soma, reflecting differential control by multiple voltage-dependent channels, including sodium channels, Cav3 channels, Kv7 channels, and HCN channels. Kv7 current is highly localized to the axon and HCN current to the soma and dendrite...
March 3, 2018: Neuron
Stylianos Michalakis, Elvir Becirovic, Martin Biel
The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration...
March 7, 2018: International Journal of Molecular Sciences
Daniel W Fisher, Phillip Luu, Neha Agarwal, Jonathan E Kurz, Dane M Chetkovich
Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels are important regulators of excitability in neural, cardiac, and other pacemaking cells, which are often altered in disease. In mice, loss of HCN2 leads to cardiac dysrhythmias, persistent spike-wave discharges similar to those seen in absence epilepsy, ataxia, tremor, reduced neuropathic and inflammatory pain, antidepressant-like behavior, infertility, and severely restricted growth. While many of these phenotypes have tissue-specific mechanisms, the cause of restricted growth in HCN2 knockout animals remains unknown...
2018: PloS One
Bryan VanSchouwen, Giuseppe Melacini
Hyperpolarization-activated cyclic-nucleotide-modulated (HCN) ion channels control rhythmicity in neurons and cardiomyocytes. Cyclic AMP (cAMP) modulates HCN activity through the cAMP-induced formation of a tetrameric gating ring spanning the intracellular region (IR) of HCN. Although evidence from confocal patch-clamp fluorometry indicates that the cAMP-dependent gating of HCN occurs through a dimer of dimers, the structural and dynamical basis of cAMP allostery in HCN dimers has so far remained elusive. Thus, here we examine how dimers influence IR structural dynamics, and the role that such structural dynamics play in HCN allostery...
February 20, 2018: Journal of Physical Chemistry. B
Fan He, Zhenxing Yang, Xingyou Dong, Zhenqiang Fang, Qian Liu, Xiaoyan Hu, Shanhong Yi, Longkun Li
OBJECTIVE: To explore the role of HCN channels in ureteral peristaltic dysfunction by comparing the changes in HCN channel levels between normal and tuberculous ureters. METHODS: A total of 32 specimens of human upper ureters were collected by nephrectomy from patients with renal tumor (control group, n = 16) or from patients with renal tuberculosis (experimental group, n = 16); the two groups did not receive radiotherapy, chemotherapy, immunotherapy, or any other special treatment before the surgical procedure...
February 19, 2018: International Urology and Nephrology
Derek L F Garden, Marlies Oostland, Marta Jelitai, Arianna Rinaldi, Ian Duguid, Matthew F Nolan
Cerebellar climbing-fiber-mediated complex spikes originate from neurons in the inferior olive (IO), are critical for motor coordination, and are central to theories of cerebellar learning. Hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels expressed by IO neurons have been considered as pacemaker currents important for oscillatory and resonant dynamics. Here, we demonstrate that in vitro, network actions of HCN1 channels enable bidirectional glutamatergic synaptic responses, while local actions of HCN1 channels determine the timing and waveform of synaptically driven action potentials...
February 13, 2018: Cell Reports
Madoka Akimoto, Bryan VanSchouwen, Giuseppe Melacini
The hyperpolarization-activated cyclic-nucleotide-gated (HCN) ion channels control nerve impulse transmission and cardiac pacemaker activity. The modulation by cAMP is critical for the regulatory function of HCN in both neurons and cardiomyocytes, but the underlying mechanism is not fully understood. Here, we show how the structure of the apo cAMP-binding domain of the HCN4 isoform has contributed to a model for the cAMP-dependent modulation of the HCN ion-channel. This model recapitulates the structural and dynamical changes that occur along the thermodynamic cycle arising from the coupling of cAMP-binding and HCN self-association equilibria...
February 14, 2018: FEBS Journal
Andrew S Bohannon, John J Hablitz
Layer 1 (L1) interneurons (INs) play a key role in modulating the integration of inputs to pyramidal neurons (PNs) and controlling cortical network activity. Hyperpolarization-activated, cyclic nucleotide-gated, non-specific cation (HCN) channels are known to alter the intrinsic and synaptic excitability of principal components (PCs) as well as select populations of GABAergic INs. However, the developmental profile and functional role of HCN channels in diverse L1 IN populations is not completely understood...
2018: Frontiers in Cellular Neuroscience
Qian Liu, Chao Wu, Shengquan Huang, Qingjian Wu, Tao Zhou, Xiaobing Liu, Xin Liu, Xiaoyan Hu, Longkun Li
Spinal cord injury (SCI) leads to bereft voluntary control of bladder, but the possible role of spontaneous excited system in bladder of SCI patients is poorly understood. Hyper-polarization-activated cyclic nucleotide-gated (HCN) channels are deemed to regulate the spontaneous contraction of bladder, our study explored the functional role of HCN channels in SCI induced neurogenic bladder. Sixty female Sprague-Dawley rats were randomized into control, sham and SCI groups. Rat models subjected to SCI at S2 levels were successfully established and were assessed using hematoxylin and eosin staining and cystometry...
February 13, 2018: International Journal of Molecular Medicine
Federica Frigerio, Corey Flynn, Ye Han, Kyle Lyman, Joaquin N Lugo, Teresa Ravizza, Antoine Ghestem, Julika Pitsch, Albert Becker, Anne E Anderson, Annamaria Vezzani, Dane Chetkovich, Christophe Bernard
Neuroinflammation is consistently found in many neurological disorders, but whether or not the inflammatory response independently affects neuronal network properties is poorly understood. Here, we report that intracerebroventricular injection of the prototypical inflammatory molecule lipopolysaccharide (LPS) in rats triggered a strong and long-lasting inflammatory response in hippocampal microglia associated with a concomitant upregulation of Toll-like receptor (TLR4) in pyramidal and hilar neurons. This, in turn, was associated with a significant reduction of the dendritic hyperpolarization-activated cyclic AMP-gated channel type 1 (HCN1) protein level while Kv4...
February 9, 2018: Molecular Neurobiology
Kuihao Chen, Dongchuan Zuo, Sho-Ya Wang, Haijun Chen
Spontaneous rhythmic action potential or pacemaking activity of pacemaker cells controls rhythmic signaling such as heartbeat. The mechanism underlying the origin of pacemaking activity is not well understood. In this study, we created human embryonic kidney (HEK) 293 cells that show pacemaking activity through heterologous expression of strong inward rectifier K+ channels (Kir2.1), hyperpolarization-activated cyclic nucleotide-gated nonselective cation channels (HCN2), and voltage-gated Na+ or Ca2+ channels (Nav1...
January 12, 2018: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Hsing-Jung Lai, Chien-Lin Chen, Li-Kai Tsai
Objective The pathophysiology of spinal muscular atrophy (SMA) is still unclear. Methods The nerve excitability test in SMA patients and a mouse model of SMA was carried out to explore the pathophysiology of nodal and internodal currents, and quantitative PCR, Western blotting and whole-cell patch-clamp recording were used for the identified hypothesis. Results The nerve excitability test in SMA patients showed increased inward rectification in the current-threshold relationship and increased overshoot after hyperpolarizing threshold electrotonus, which indicates increased hyperpolarization-activated cyclic nucleotide-gated (HCN) current; these findings correlated with disease severity...
February 2, 2018: Annals of Neurology
Dirk Weihrauch, Garett Joseph, Patrick Allen
Invertebrates employ a variety of ammonia excretion strategies to facilitate their survival in diverse aquatic environments, including freshwater, seawater and the water film surrounding soil particles. Various environmental properties set innate challenges for an organism's ammonia excretory capacity. These include the availability of NaCl and the respective ion-permeability of the organism's transport epithelia, and the buffering capacity of their immediate surrounding medium. To this end, some transporters seem to be conserved in the excretory process...
January 29, 2018: Journal of Experimental Biology
Weihua Ding, Zerong You, Shiqian Shen, Jinsheng Yang, Grewo Lim, Jason T Doheny, Shengmei Zhu, Yi Zhang, Lucy Chen, Jianren Mao
Orofacial neuropathic pain caused by trigeminal nerve injury is a debilitating condition with limited therapeutic options. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels regulate neuronal excitability and are involved in the development and maintenance of chronic pain. However, the effect of HCN channel activity in the Gasserian ganglion on trigeminal neuropathic pain has not been examined. We evaluated nociceptive behaviors after microinjection of the HCN channel blockers ZD7288 or ivabradine into the Gasserian ganglion in rats with trigeminal nerve injury...
January 31, 2018: Journal of Pain: Official Journal of the American Pain Society
Stephanie Hans, Alex R Quijada-Rodriguez, Garett J P Allen, Horst Onken, Jason R Treberg, Dirk Weihrauch
Many studies have investigated ammonia excretion and acid-base regulation in aquatic arthropods, yet current knowledge of marine chelicerates is non-existent. In American horseshoe crabs (Limulus polyphemus), book gills bear physiologically distinct regions: dorsal and ventral half-lamellae, and central mitochondria-rich (CMRA) and peripheral mitochondria-poor areas (PMPA). CMRA and ventral half-lamella exhibited characteristics important to ammonia excretion and/or acid-base regulation as supported by high expression levels of Rhesus-protein 1 (LpRh-1), cytoplasmic carbonic anhydrase (CA-2), and hyperpolarization-activated cyclic nucleotide-gated K+ channel (HCN) compared to PMPA and dorsal half-lamella...
January 18, 2018: Journal of Experimental Biology
Sheng-Tao Yang, Min Wang, Constantinos D Paspalas, Johanna L Crimins, Marcus T Altman, James A Mazer, Amy F T Arnsten
Neurons in primary visual cortex (V1) are more resilient than those in dorsolateral prefrontal cortex (dlPFC) in aging, schizophrenia and Alzheimer's disease. The current study compared glutamate and neuromodulatory actions in macaque V1 to those in dlPFC, and found striking regional differences. V1 neuronal firing to visual stimuli depended on AMPA receptors, with subtle NMDA receptor contributions, while dlPFC depends primarily on NMDA receptors. Neuromodulatory actions also differed between regions. In V1, cAMP signaling increased neuronal firing, and the phosphodiesterase PDE4A was positioned to regulate cAMP effects on glutamate release from axons...
January 17, 2018: Cerebral Cortex
F Resta, L Micheli, A Laurino, V Spinelli, T Mello, L Sartiani, L Di Cesare Mannelli, E Cerbai, C Ghelardini, M N Romanelli, G Mannaioni, A Masi
Chemotherapy-Induced Peripheral Neuropathy (CIPN) is the most frequent adverse effect of pharmacological cancer treatments. The occurrence of neuropathy prevents the administration of fully-effective drug regimen, affects negatively the quality of life of patients, and may lead to therapy discontinuation. CIPN is currently treated with anticonvulsants, antidepressants, opioids and non-opioid analgesics, all of which are flawed by insufficient anti-hyperalgesic efficacy or addictive potential. Understandably, developing new drugs targeting CIPN-specific pathogenic mechanisms would dramatically improve efficacy and tolerability of anti-neuropathic therapies...
January 12, 2018: Neuropharmacology
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