Mechanosensitive ion channels (MSCs) are key molecules in the mechano-electrical transduction of arterial baroreceptors. Among them, acid-sensing ion channel 2 (ASIC2) and transient receptor potential vanilloid subfamily member 1 (TRPV1) have been studied extensively and documented to play important roles. In this study, experiments using aortic arch-aortic nerve preparations isolated from rats revealed that both ASIC2 and TRPV1 are functionally necessary, as blocking either abrogated nearly all pressure-dependent neural discharge. However, whether ASIC2 and TRPV1 work in coordination remained unclear. So we carried out cell-attached patch-clamp recordings in HEK293T cells co-expressing ASIC2 and TRPV1 and found that inhibition of ASIC2 completely blocked stretch-activated currents while inhibition of TRPV1 only partially blocked these currents. Immunofluorescence staining of aortic arch-aortic adventitia from rats showed that ASIC2 and TRPV1 are co-localized in the aortic nerve endings, and co-immunoprecipitation assays confirmed that the two proteins form a compact complex in HEK293T cells and in baroreceptors. Moreover, protein modeling analysis, exogenous co-immunoprecipitation assays, and biotin pull-down assays indicated that ASIC2 and TRPV1 interact directly. In summary, our research suggests that ASIC2 and TRPV1 form a compact complex and function synergistically in the mechano-electrical transduction of arterial baroreceptors. The model of synergism between MSCs may have important biological significance beyond ASIC2 and TRPV1.
Acid Sensing Ion Channels/physiology* ; Animals ; HEK293 Cells ; Humans ; Pressoreceptors/physiology* ; Rats ; TRPV Cation Channels/physiology*

Ion channels mediate ion transport across membranes, and play vital roles in processes of matter exchange, energy transfer and signal transduction in living organisms. Recently, structural studies of ion channels have greatly advanced our understanding of their ion selectivity and gating mechanisms. Structural studies of voltage-gated potassium channels elucidate the structural basis for potassium selectivity and voltage-gating mechanism; structural studies of voltage-gated sodium channels reveal their slow and fast inactivation mechanisms; and structural studies of transient receptor potential (TRP) channels provide complex and diverse structures of TRP channels, and their ligand gating mechanisms. In the article we summarize recent progress on ion channel structural biology, and outlook the prospect of ion channel structural biology in the future.
Ion Channel Gating ; physiology ; Ion Channels ; Voltage-Gated Sodium Channels ; chemistry ; metabolism

Recently, more and more studies have discovered that some diseases result from gene defect and functional variation of ion channels, which are called ion passage diseases or ion channelopathies. Meanwhile, it has been found that even though many diseases do not fall into the category of the ion passage disease, some links or passages during the disease development are closely related with the malfunction of ion channels, and many drugs can prevent and cure these diseases by acting on ion channels. Therefore, the relationship between physiology/pathophysiology and ion channels is gradually becoming one of the hot topics in the current researches. The recent progress in the researches on the relationship between penile erection and ion channels is briefly reviewed in this article.
Calcium Channels ; physiology ; Chloride Channels ; physiology ; Connexin 43 ; genetics ; Erectile Dysfunction ; etiology ; Humans ; Ion Channels ; physiology ; Male ; Penile Erection ; physiology ; Potassium Channels ; physiology

The mathematical models for simulation of cardiac sodium, potassium and calcium channel kinetics courses and currents were developed to simulate the properties of ionic currents and channel dynamic courses. With modifications of these models, it is possible to make them integrated for simulating the whole process of action potential, thus additional discussion on ionic mechanism could provide a theoretical foundation for further animal experiments and clinical applications.
Action Potentials ; Algorithms ; Calcium Channels ; physiology ; Computer Simulation ; Ion Channels ; physiology ; Membrane Potentials ; Models, Cardiovascular ; Myocytes, Cardiac ; physiology ; Potassium Channels ; physiology ; Sodium Channels ; physiology

The regulation of vascular and trabecular smooth muscle relaxation or contraction in the penis, that is, the physiology of corporal smooth muscle tone, determines penile erection or flaccidity. There is considerable evidence that the potassium channel and calcium channel, like many other vascular tissues, are the major modulators of smooth muscle tone in the corpora. Moreover, data on cultured corporal smooth muscle cells and isolated corporal tissue strips have demonstrated that the neurotransmitters participating in erection modulate corporal smooth muscle tone largely through their effects on ionic channels and transmembrane ionic flux.
Cell Line ; Humans ; Ion Channels ; physiology ; Male ; Muscle Contraction ; physiology ; Muscle, Smooth ; cytology ; physiology ; Penis ; cytology ; physiology ; Potassium Channels ; physiology ; Sodium Channels ; physiology

Cell Line ; Cyclic Nucleotide-Gated Cation Channels ; physiology ; Humans ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; Ion Channels ; physiology ; Membrane Potentials ; Muscle Proteins ; physiology ; Potassium Channels

The electrical excitability of the dendrites of the cortical neurons was first studied on the apical dendrites of the pyramidal neurons. Professor ZHANG Xiang-Tong (H-T Chang) made important contributions in the fifties of last century on this topic. Through numerous studies later on, it has been established that the electrical excitability of dendrites of different types of neurons, even different dendrites in the same neuron is different. For the apical dendrites of the cortical pyramidal neurons, neither a single nor a train of repetitive action potentials with constant frequency can reach its terminal portion. However, some of the burst repetitive responses with non-constant frequency of the apical dendrite elicited by direct current injected into the soma may reach the terminal portion. This may be due to: (1) the calcium ion concentration in the apical dendrite is increased by the burst activities, which, in turn, increases the electrical excitability of the apical dendrite and /or (2) some retrograde collaterals of axon of the activated soma reach the apical dendrite and release neurotransmitter glutamate, which changes the properties of the voltage-gated ion channels in the apical dendrite. Low electrical excitability of the apical dendrites seems to be essential for the processing of numerous income signals to the terminal portion of the apical dendrites.
Action Potentials ; Animals ; Dendrites ; physiology ; Electrophysiological Phenomena ; Ion Channels ; physiology ; Pyramidal Cells ; physiology ; Synaptic Transmission

The reconstruction of tactile function during the repair of skin damage caused by factors including burns is inseparable from the functional regeneration of tactile receptor Merkel cells. Merkel cells mainly exist in the basal layer of the epidermis and are closely connected with nerves to form Merkel cell-nerve complexes, which play an important role in biological organisms. A large number of studies have shown that Merkel cells conduct precise transmission of mechanical force stimuli through the mechanically gated ion channels PIEZO2, and perform the function of tactile receptors. In this paper, we discussed the characteristics of Merkel cells and analyzed the different subgroups that may possibly exist in this type of cells and their functions, at the same time, we investigated the animal model research of touch-related diseases and the clinical diseases related to touch, revealing the importance of Merkel cell function research.
Animals ; Ion Channels/metabolism* ; Mechanotransduction, Cellular/physiology* ; Merkel Cells/physiology* ; Skin/metabolism* ; Touch/physiology*

Mitochondrial complex inhibition has been described in the pathophysiology of many neurodegenerative diseases, and the functional changes of neuron induced by mitochondrial complex inhibition and the mechanism are concerned. Neuronal function depends on action potentials and neurotransmitter release. Voltage dependent sodium/potassium ion channels mediate generation of neuron action potentials. And voltage dependent calcium ion channels are directly involved in the process of neurotransmitter release. The functional changes of those ion channels under some pathological conditions can induce neuron dysfunction, even death. Therefore, understanding the influence of mitochondrial complex inhibition on neuronal ion channels and neurotransmitter release is helpful to illuminate the pathophysiology of neurodegenerative diseases. This review will highlight recent progress in this field.
Action Potentials ; Biological Transport ; Calcium Channels ; physiology ; Humans ; Ion Channels ; physiology ; Mitochondria ; physiology ; Neurodegenerative Diseases ; physiopathology ; Neurons ; physiology ; Neurotransmitter Agents ; physiology ; Potassium Channels ; physiology ; Sodium Channels ; physiology ; Synaptic Transmission

The knowledge about electrophysiological properties of retinal ganglion cells (RGCs), as well as modulation of these properties, is important not only for understanding the unique physiological functions of RGCs under normal conditions, but also for exploring the cellular mechanisms of retinal neurodegeneration diseases, such as glaucoma. In this paper, we reviewed the progress in electrophysiological studies of RGCs by using patch-clamp techniques, concerning the voltage-gated ion channels, the ligand-gated ion channels and the effects of neuromodulators on these channels.
Animals ; Electrophysiological Phenomena ; Humans ; Ion Channels ; physiology ; Patch-Clamp Techniques ; Retinal Ganglion Cells ; physiology