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A 15-year-old girl was admitted to emergency department with an acute flaccid tetraparesis with no other symptoms. A history of recurrent similar episodes with spontaneous recovery was reported and no family history was known. Laboratory tests revealed severe hypokalaemia and hypokaluria. Symptoms resolution occurred after potassium replacement. The diagnosis of hypokalaemic periodic paralysis (HPP) was confirmed by genetic testing, which revealed a not previously described mutation in

No medications are approved for cannabis use disorder (CUD), though a small clinical trial demonstrated that the voltage-dependent calcium channel (VDCC) ligand gabapentin reduced cannabis use in treatment seekers. VDCCs are modulated by cannabinoid (CB) ligands, and there are shared effects between CB agonists and VDCC ligands. This overlapping neuropharmacology and the initial clinical results supported the evaluation of pregabalin, a "next-generation" VDCC ligand, as a CUD medication. Two separate placebo-controlled, double-blind, counterbalanced, within-subjects human laboratory studies tested placebo and 300 (N = 2 females, 11 males; Experiment [EXP] 1) or 450 (N = 3 females, 11 males; EXP 2) mg/day pregabalin in cannabis users who were not seeking treatment or trying to reduce/quit their cannabis use. The protocol consisted of two outpatient maintenance phases (11 days in EXP 1 and 15 days in EXP 2) that concluded with four experimental sessions within each phase. During experimental sessions, maintenance continued, and participants completed two 2-day blocks of sampling and self-administration sessions to determine the reinforcing effects of smoked cannabis (0% and 5.9% delta⁹-tetrahydrocannabinol [THC]), as well as subjective, attentional bias, performance, and physiological responses. In addition, naturalistic cannabis use, side effects, sleep quality, craving, and other self-reported substance use were measured during pregabalin maintenance. Cannabis was self-administered and produced prototypical effects, but pregabalin generally did not impact the effects of cannabis or alter naturalistic use. These human laboratory results in cannabis users not trying to reduce/quit their use do not support the efficacy of pregabalin as a stand-alone pharmacotherapy for CUD. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Hypokalemic periodic paralysis (HypoPP) is a channelopathy of skeletal muscle caused by missense mutations in the voltage sensor domains (usually at an arginine of the S4 segment) of the Ca

Kinetic analysis of intracellular calcium (Ca

Cardiovascular disease continues to be the leading health burden worldwide and with the rising rates in obesity and type II diabetes and ongoing effects of long COVID, it is anticipated that the burden of cardiovascular morbidity and mortality will increase. Calcium is essential to cardiac excitation and contraction. The main route for Ca

Gabapentinoids are specific ligands for the α2δ-1 subunit of voltage-gated calcium channels. This class of drugs, including gabapentin and pregabalin, exert various pharmacological effects and are widely used for the treatment of epilepsy, anxiety, and chronic pain. The mechanism of action of gabapentinoids involves both direct modulation of calcium channel kinetics and inhibition of channel trafficking and expression, which contribute to the above pharmacological effects. In the present study, we investigated the effects of mirogabalin, a novel potent gabapentinoid, on expression levels of the α2δ-1 subunit in the spinal dorsal horn in a rat model of spinal nerve ligation (SNL) as an experimental animal model for peripheral neuropathic pain. The neuropathic pain state was induced by SNL in male Sprague – Dawley rats. After the development of mechanical hypersensitivity, the animals received 10 mg/kg mirogabalin or vehicle orally for 5 consecutive days and were subjected to immunohistochemical analysis of α2δ-1 subunit expression in the spinal cord. In the SNL model rats, expression of the α2δ-1 subunit significantly increased in the spinal dorsal horn at the ipsilateral side of nerve injury, while mirogabalin inhibited this increase. In conclusion, the α2δ-1 subunit was upregulated in the spinal dorsal horn of SNL model rats, and repeated administration of mirogabalin inhibited this upregulation. The inhibitory effect of mirogabalin on upregulation of the α2δ-1 subunit after nerve injury is considered to contribute to its analgesic effects in peripheral neuropathic pain.

The mechanisms underlying the disruption of excitation-contraction (EC) coupling in dystrophin-deficient muscles are not well understood. Here, using animal models for Duchenne muscular dystrophies (DMD), we show a Ca2+-dependent protease (calpain-1)-mediated proteolysis of SH3 and cysteine-rich domain 3 (STAC3) and junctophilin 1 (JP1), essential EC coupling proteins, in dystrophin-deficient muscle, and highlighting the dissociation of STAC3 and JP1 from dihydropyridine receptor as a causative factor in EC uncoupling of dystrophic muscles.

Retinal bipolar cells (BCs) compose the canonical vertical excitatory pathway that conveys photoreceptor output to inner retinal neurons. Although synaptic transmission from BC terminals is thought to rely almost exclusively on Ca(2+) influx through voltage-gated Ca(2+) (Ca(V)) channels mediating L-type currents, the molecular identity of Ca(V) channels in BCs is uncertain. Therefore, we combined molecular and functional analyses to determine the expression profiles of Ca(V) α(1), β, and α(2)δ subunits in mouse rod bipolar (RB) cells, BCs from which the dynamics of synaptic transmission are relatively well-characterized. We found significant heterogeneity in Ca(V) subunit expression within the RB population from mice of either sex, and significantly, we discovered that transmission from RB synapses was mediated by Ca(2+) influx through P/Q-type (Ca(V)2.1) and N-type (Ca(V)2.2) conductances as well as the previously-described L-type (Ca(V)1) and T-type (Ca(V)3) conductances. Furthermore, we found both Ca(V)1.3 and Ca(V)1.4 proteins located near presynaptic ribbon-type active zones in RB axon terminals, indicating that the L-type conductance is mediated by multiple Ca(V)1 subtypes. Similarly, Ca(V)3 α(1), β, and α(2)δ subunits also appear to obey a “multisubtype” rule, i.e., we observed a combination of multiple subtypes, rather than a single subtype as previously thought, for each Ca(V) subunit in individual cells. SIGNIFICANCE STATEMENT Bipolar cells (BCs) transmit photoreceptor output to inner retinal neurons. Although synaptic transmission from BC terminals is thought to rely almost exclusively on Ca(2+) influx through L-type voltage-gated Ca(2+) (Ca(V)) channels, the molecular identity of Ca(V) channels in BCs is uncertain. Here, we report unexpectedly high molecular diversity of Ca(V) subunits in BCs. Transmission from rod bipolar (RB) cell synapses can be mediated by Ca(2+) influx through P/Q-type (Ca(V)2.1) and N-type (Ca(V)2.2) conductances as well as the previously-described L-type (Ca(V)1) and T-type (Ca(V)3) conductances. Furthermore, Ca(V)1, Ca(V)3, β, and α(2)δ subunits appear to obey a “multisubtype” rule, i.e., a combination of multiple subtypes for each subunit in individual cells, rather than a single subtype as previously thought.

Context Due to its rare incidence, molecular features of primary aldosteronism (PA) in young adults are largely unknown. Recently developed targeted mutational analysis identified aldosterone-driver somatic mutations in aldosterone-producing lesions, including aldosterone-producing adenomas (APAs), aldosterone-producing nodules (APNs), and aldosterone-producing micronodules, formerly known as aldosterone-producing cell clusters. Objective To investigate histologic and genetic characteristics of lateralized PA in young adults. Methods Formalin-fixed, paraffin-embedded adrenal tissue sections from 74 young patients with lateralized PA ( Results Based on the CYP11B2 IHC results, histopathologic classification was made as follows: 48 APAs, 20 APNs, 2 multiple aldosterone-producing nodules (MAPN), 1 double APN, 1 APA with MAPN, and 2 nonfunctioning adenomas (NFAs). Of 45 APAs with successful sequencing, 43 (96%) had somatic mutations, with KCNJ5 mutations being the most common genetic cause of young-onset APA (35/45, 78%). Of 18 APNs with successful sequencing, all of them harbored somatic mutations, with CACNA1D mutations being the most frequent genetic alteration in young-onset APN (8/18, 44%). Multiple CYP11B2-expressing lesions in patients with MAPN showed several aldosterone-driver mutations. No somatic mutations were identified in NFAs. Conclusion APA is the most common histologic feature of lateralized PA in young adults. Somatic KCNJ5 mutations are common in APAs, whereas CACNA1D mutations are often seen in APNs in this young PA population.

A role for voltage-gated calcium channels (VGCCs) in psychiatric disorders has long been postulated as part of a broader involvement of intracellular calcium signalling. However, the data were inconclusive and hard to interpret. We review three areas of research that have markedly advanced the field. First, there is now robust genomic evidence that common variants in VGCC subunit genes, notably CACNA1C which encodes the L-type calcium channel (LTCC) CaV1.2 subunit, are trans-diagnostically associated with psychiatric disorders including schizophrenia and bipolar disorder. Rare variants in these genes also contribute to the risk. Second, pharmacoepidemiological evidence supports the possibility that calcium channel blockers, which target LTCCs, might have beneficial effects on the onset or course of these disorders. This is especially true for calcium channel blockers that are brain penetrant. Third, long-range sequencing is revealing the repertoire of full-length LTCC transcript isoforms. Many novel and abundant CACNA1C isoforms have been identified in human and mouse brain, including some which are enriched compared to heart or aorta, and predicted to encode channels with differing functional and pharmacological properties. These isoforms may contribute to the molecular mechanisms of genetic association to psychiatric disorders. They may also enable development of therapeutic agents that can preferentially target brain LTCC isoforms and be of potential value for psychiatric indications.

The L-type calcium currents conducted by the cardiac Ca

Melzer discusses a recent JGP study showing that alternative splicing of the skeletal muscle L-type calcium channel impacts on a modulatory effect of its γ subunit.

L-type Ca

Previous findings have indicated that glucocorticoid hormones impair working memory via an interaction with the β-adrenoceptor-cAMP signaling cascade to rapidly increase cAMP-dependent protein kinase (PKA) activity within the prefrontal cortex (PFC). However, it remains elusive how such activation of PKA can affect downstream cellular mechanisms in regulating PFC cognitive function. PKA is known to activate l-type voltage-gated Ca

Intestinal microbiota and microbiota-derived metabolites play a key role in regulating the host physiology. Recently, we have identified a gut-bacterial metabolite, namely 5-hydroxyindole, as a potent stimulant of intestinal motility via its modulation of L-type voltage-gated calcium channels located on the intestinal smooth muscle cells. Dysregulation of L-type voltage-gated calcium channels is associated with various gastrointestinal motility disorders, including constipation, making L-type voltage-gated calcium channels an important target for drug development. Nonetheless, the majority of currently available drugs are associated with alteration of the gut microbiota. Using 16S rRNA sequencing this study shows that, when administered orally, 5-hydroxyindole has only marginal effects on the rat cecal microbiota. Molecular dynamics simulations propose potential-binding pockets of 5-hydroxyindole in the α1 subunit of the L-type voltage-gated calcium channels and when its stimulatory effect on the rat colonic contractility was compared to 16 different analogues, ex-vivo, 5-hydroxyindole stood as the most potent enhancer of the intestinal contractility. Overall, the present findings imply a potential role of microbiota-derived metabolites as candidate therapeutics for targeted treatment of slow intestinal motility-related disorders including constipation.

Voltage-gated calcium (CaV) channels form three subfamilies (CaV1–3). The CaV1 and CaV2 channels are heteromeric, consisting of an α1 pore-forming subunit, associated with auxiliary CaVβ and α2δ subunits. The α2δ subunits are encoded in mammals by four genes, CACNA2D1–4. They play important roles in trafficking and function of the CaV channel complexes. Here we report biallelic variants in CACNA2D1, encoding the α2δ-1 protein, in two unrelated individuals showing a developmental and epileptic encephalopathy. Patient 1 has a homozygous frameshift variant c.818_821dup/p.(Ser275Asnfs*13) resulting in nonsense-mediated mRNA decay of the CACNA2D1 transcripts, and absence of α2δ-1 protein detected in patient-derived fibroblasts. Patient 2 is compound heterozygous for an early frameshift variant c.13_23dup/p.(Leu9Alafs*5), highly probably representing a null allele and a missense variant c.626G>A/p.(Gly209Asp). Our functional studies show that this amino-acid change severely impairs the function of α2δ-1 as a calcium channel subunit, with strongly reduced trafficking of α2δ-1G209D to the cell surface and a complete inability of α2δ-1G209D to increase the trafficking and function of CaV2 channels. Thus, biallelic loss-of-function variants in CACNA2D1 underlie the severe neurodevelopmental disorder in these two patients. Our results demonstrate the critical importance and non-interchangeability of α2δ-1 and other α2δ proteins for normal human neuronal development.

Each heartbeat is initiated by the action potential, an electrical signal that depolarizes the plasma membrane and activates a cycle of calcium influx via voltage-gated calcium channels, calcium release via ryanodine receptors, and calcium reuptake and efflux via calcium-ATPase pumps and sodium-calcium exchangers. Agonists of the sympathetic nervous system bind to adrenergic receptors in cardiomyocytes, which, via cascading signal transduction pathways and protein kinase A (PKA), increase the heart rate (chronotropy), the strength of myocardial contraction (inotropy), and the rate of myocardial relaxation (lusitropy). These effects correlate with increased intracellular concentration of calcium, which is required for the augmentation of cardiomyocyte contraction. Despite extensive investigations, the molecular mechanisms underlying sympathetic nervous system regulation of calcium influx in cardiomyocytes have remained elusive over the last 40 years. Recent studies have uncovered the mechanisms underlying this fundamental biologic process, namely that PKA phosphorylates a calcium channel inhibitor, Rad, thereby releasing inhibition and increasing calcium influx. Here, we describe an updated model for how signals from adrenergic agonists are transduced to stimulate calcium influx and contractility in the heart. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The pro-inflammatory cytokine tumor necrosis factor (TNF)-α augments intracellular Ca2+ signaling and contractile responses of airway smooth muscles, leading to airway hyperresponsiveness (AHR). However, the underlying mechanism has not been fully elucidated. This study aims to investigate the cellular mechanism of the potentiated contraction of mouse tracheal smooth muscle induced by TNF-α. The results revealed that TNF-α triggered facilitation of mouse tracheal smooth muscle contraction in an epithelium-independent manner. The TNF-α-induced hypercontractility could be suppressed by the protein kinase C (PKC) inhibitor GF109203X, the tyrosine kinase inhibitor genistein, the Src inhibitor PP2 or the L-type voltage-dependent Ca2+ channel blocker nifedipine. After TNF-α incubation, the α1C L-type Ca2+ channel (CaV1.2) was up-regulated in primary cultured mouse tracheal smooth muscle cells. Pronounced phosphotyrosine level was also observed in mouse tracheas. In conclusion, this study demonstrated that TNF-α enhanced airway smooth muscle contraction via PKC- Src-CaV1.2 pathways, which provides novel insights into the pathological role of pro-inflammatory cytokines in mediating AHR.

Circadian locomotor output cycles kaput protein (CLOCK) plays a crucial role in glucose homeostasis and controlling insulin secretion. However, the mechanism of the CLOCK regulating rhythmic insulin secretion has not been fully understood.Rhythmic expression of the CLOCK in rat pancreatic beta cell was detected. INS-1 cells were transfected with siRNAs to knockdown the CLOCK before the cells were incubated with different concentrations of glucose. Insulin secretion was analyzed by ELISA method. Expression of the L-type calcium channel protein (Cav1.2, Cacna1c) was determined both in the CLOCK-knockdown cells and the control cells. Calcium influx was probed by fluorescent. Chromatin immunoprecipitation (ChIP) test and dual-luciferase reporter gene experiments were applied to verify the relationship between the CLOCK and Cav1.2.The CLOCK is abundantly expressed in rat pancreatic beta cells. Transcription level of the CLOCK showed rhythmicity in the beta cells. Compared to the control group, insulin release was significantly impaired with 25 mM glucose incubation in the CLOCK-knockdown group, but not showed with 2.5 mM glucose incubation. The expression of Cav1.2 and the influx of calcium were significantly decreased in the CLOCK-knockdown group with 25 mM glucose incubation. ChIP test indicted that the CLOCK bound to -444∼-454 region of the Cacna1c promoter of the INS-1 cells, but the binding was significantly reduced following the CLOCK-knockdown. Luciferase experiment was in accordance with the finding of ChIP.The CLOCK mediating Cav

Striated muscle L-type calcium channels (LTCC) are localized specifically to the junctional membrane (JM) where the sarcolemma is closely apposed to the sarcoplasmic reticulum. Although this allocation of LTCC is critical for efficient excitation-contraction coupling in striated muscles, its underlying molecular mechanism has not been clarified. Junctophilins (JPs) stabilize the structure of JM by bridging the sarcolemmal and SR membranes. In addition, immunoprecipitation and pull-down assay revealed that the proximal C-terminus of Ca

INTRODUCTION LQTS is of great importance as it is the most common cause of sudden cardiac death in childhood. The diagnosis is made by the prolongation of the QTc interval on the ECG. However, clinical heterogeneity and non-diagnostic QTc intervals may cause a delay in the diagnosis. In such cases, genetic tests such as NGS panel analysis enable a definitive diagnosis. We present the first study that aimed to expand the LQTS's mutational spectrum by NGS panel analysis from Turkey. METHODS Fifty-seven unrelated patients with clinically diagnosed LQTS were investigated using an NGS panel that includes six LQTS-related genes. Clinical aspects, outcome, and molecular analysis results were reviewed. RESULTS Pathogenic(53%)/likely pathogenic(23%)/VUS(4%) variants were detected in any of the genes examined in 79% of the patients. Among all detected variants, KCNQ1(71%) was the most common gene, followed by SCN5A(11%), KCNH2(10%), CALM1(5%), and CACNA1C(3%). Twelve novel variants were detected. Among the variants in KCNQ1, the c.1097G>A variant was present in 42% of patients. This variant also composed 31% of the variants detected in all of the genes. CONCLUSION Our study expands the spectrum of the variations associated with LQTS with twelve novel variants in five genes. And also it draws attention to the frequency of the KCNQ1 c.1097G>A variant and forms the basis for new studies to determine the possible founder effect in the Turkish population. Furthermore, identifying new variants and clinical findings has importance in elaborating the roles of related genes in pathophysiology and determining the variable expression and incomplete penetration rates in this syndrome. This article is protected by copyright. All rights reserved.

The interaction between L-type voltage-dependent Ca2+ channels and the endocannabinoid system (eCs) in synaptic plasticity is controversial. In the present research, the impact of acute administration of URB597, as an endocannabinoid breakdown inhibitor, was evaluated after chronic injection of verapamil, as a Ca2+ channels blocker, on inducing long-term potentiation (LTP) in the rat's hippocampal dentate gyrus (DG). Treatment of male Wistar rats was done using intraperitoneal(i.p) injection of verapamil hydrochloride (n = 8) and saline (n = 10), as the solvent of verapamil once a day within 13 days. Anesthetization was done by i.p injection of urethane and the rats were located in the stereotaxic apparatus for surgery, electrode implantation, and field potential recording. After observing a steady-state baseline response, saline or URB597 were injected (n = 9). Measurement of the population spike (PS) amplitude and slope of field excitatory postsynaptic potentials (fEPSPs) in the DG region was performed as a result of perforant pathway (PP) stimulation. Our treatments could inhibit LTP. Our results indicated that the chronic administration of verapamil produced a significant decrease in the slope of fEPSP and PS amplitude. Also, acute URB597 administration decreased the slope of fEPSP and PS amplitude compared to the saline group. Moreover, URB597 administration in combination with chronic administration of verapamil produced a greater decrease in fEPSP slope and PS amplitude than the saline group. These findings indicated that verapamil and URB597 disrupted LTP induction in the DG. Moreover, an interaction was observed between Ca2+ channels and eCs. Therefore, the eCs possibly play a selective role in synaptic plasticity.

The advent of cost-effective high-throughput nucleotide sequencing means that information about the transcriptome is accruing at an exponential rate, rapidly refining our understanding of the diversity of gene products. It is important that these findings are readily accessible to the wider scientific community to maximise their impact. However, there are multiple barriers to their efficient dissemination and their translation into functional insights. Here, we outline how the status quo can result in information becoming siloed and/or ambiguous, using the CACNA1C gene, which encodes a voltage-gated calcium channel, as an example. We highlight three areas that pose potential barriers to effective information transfer and offer suggestions as to how these may be addressed: firstly, a lack of clarity about the strength of the evidence for individual transcripts in current annotations; secondly, limitations to the transfer of information between nucleotide and protein databases; thirdly, challenges relating to the nomenclature used for transcriptional events and RNA modifications, both for genomic researchers and the wider scientific community.

Nicotine-withdrawal after daily exposure manifests somatic and affective symptom including a range of cognitive deficits. Earlier studies suggested participation of L-type calcium channels (LTCCs) in development of nicotine dependence and expression of withdrawal signs. An upsurge in Ca2+-induced oxidative stress in brain underlies the biochemical events and behavioral signs of nicotine-withdrawal. The present study is aimed to explore the effects of lacidipine (LTCC antagonist) against nicotine-withdrawal. Swiss albino mice were administered ( −)-nicotine hydrogen tartrate (3.35 mg/kg, t.i.d.) from days 1 to 7 and alongside lacidipine (0.3, 1, and 3 mg/kg, i.p.) given from days 1 to 14. Somatic withdrawal signs were noted 48 h after last dose of nicotine. Bay-K8644 (LTCC agonist) was administered in mice subjected to nicotine-withdrawal and lacidipine (3 mg/kg) treatments. Behavioral tests of memory, anxiety, and depression were conducted on days 13 and 14 to assess the effects of lacidipine on affective symptoms of nicotine-withdrawal. Biomarkers of oxido-nitrosative were quantified in the whole brain. Nicotine-withdrawal significantly enhanced somatic signs and symptoms of anxiety, depression, and memory impairment in mice. Lacidipine (1 and 3 mg/kg) attenuated nicotine-withdrawal induced somatic symptoms and also ameliorated behavioral abnormalities. Nicotine-withdrawal triggered an upsurge in brain lipid peroxidation, total nitrite content, and decline in antioxidants, and these effects were attenuated by lacidipine. Bay-K8644 significantly abolished improvement in somatic and affective symptoms, and antioxidant effects by lacidipine in mice subjected to nicotine-withdrawal. Lacidipine mitigated nicotine-withdrawal triggered somatic and affective symptoms owing to decrease in brain oxido-nitrosative stress.

Familial periodic paralyses (PPs) are inherited disorders of skeletal muscle characterized by recurrent episodes of flaccid muscle weakness. PPs are classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. HypoPP is an autosomal dominant disease caused by mutations in the CACNA1S gene, encoding for Cav1.1 channel (HypoPP-1), or SCN4A gene, encoding for Nav1.4 channel (HypoPP-2). In the present study, we included 60 patients with a clinical diagnosis of HypoPP. Fifty-one (85%) patients were tested using the direct sequencing (Sanger method) of all reported HypoPP mutations in CACNA1S and SCN4A genes; the remaining 9 (15%) patients were analyzed through a next-generation sequencing (NGS) panel, including the whole CACNA1S and SCN4A genes, plus other genes rarely associated to PPs. Fifty patients resulted mutated: 38 (76%) cases showed p.R528H and p.R1239G/H CACNA1S mutations and 12 (24%) displayed p.R669H, p.R672C/H, p.R1132G/Q, and p.R1135H SCN4A mutations. Forty-one mutated cases were identified among the 51 patients managed with Sanger sequencing, while all the 9 cases directly analyzed with the NGS panel showed mutations in the hotspot regions of SCN4A and CACNA1S. Ten out of the 51 patients unresolved through the Sanger sequencing were further analyzed with the NGS panel, without the detection of any mutation. Hence, our data suggest that in HypoPP patients, the extension of genetic analysis from the hotspot regions using the Sanger method to the NGS sequencing of the entire CACNA1S and SCN4A genes does not lead to the identification of new pathological mutations.

This review describes interactions between compounds, primarily dihydropyridines, that block L-type calcium channels and drugs that cause dependence, and the potential importance of these interactions. The main dependence-inducing drugs covered are alcohol, psychostimulants, opioids, and nicotine. In preclinical studies, L-type calcium channel blockers prevent or reduce important components of dependence on these drugs, particularly their reinforcing actions and the withdrawal syndromes. The channel blockers also reduce the development of tolerance and/or sensitization, and they have no intrinsic dependence liability. In some instances, their effects include reversal of brain changes established during drug dependence. Prolonged treatment with alcohol, opioids, psychostimulant drugs, or nicotine causes upregulation of dihydropyridine binding sites. Few clinical studies have been carried out so far, and reports are conflicting, although there is some evidence of effectiveness of L-channel blockers in opioid withdrawal. However, the doses of L-type channel blockers used clinically so far have necessarily been limited by potential cardiovascular problems and may not have provided sufficient central levels of the drugs to affect neuronal dihydropyridine binding sites. New L-type calcium channel blocking compounds are being developed with more selective actions on subtypes of L-channel. The preclinical evidence suggests that L-type calcium channels may play a crucial role in the development of dependence to different types of drugs. Mechanisms for this are proposed, including changes in the activity of mesolimbic dopamine neurons, genomic effects, and alterations in synaptic plasticity. Newly developed, more selective L-type calcium channel blockers could be of considerable value in the treatment of drug dependence. SIGNIFICANCE STATEMENT: Dependence on drugs is a very serious health problem with little effective treatment. Preclinical evidence shows drugs that block particular calcium channels, the L-type, reduce dependence-related effects of alcohol, opioids, psychostimulants, and nicotine. Clinical studies have been restricted by potential cardiovascular side effects, but new, more selective L-channel blockers are becoming available. L-channel blockers have no intrinsic dependence liability, and laboratory evidence suggests they reverse previously developed effects of dependence-inducing drugs. They could provide a novel approach to addiction treatment.

Diabetic vasculopathy is a significant cause of morbidity and mortality in the diabetic population. Hyperglycemia, one of the central metabolic abnormalities in diabetes, has been associated with vascular dysfunction due to endothelial cell damage. However, studies also point toward vascular smooth muscle as a locus for hyperglycemia-induced vascular dysfunction. Emerging evidence implicates hyperglycemia-induced regulation of vascular L-type Ca

Neuronal L-type Ca

L-type CaA multiscale approach including patch-clamp electrophysiology, super-resolution nanoscopy, proximity ligation assay, calcium imaging' pressure myography, and Laser Speckle imaging was implemented to examine CaCaThese results suggest that PKA-dependent S1928 phosphorylation promotes the spatial reorganization of vascular α1

In skeletal muscle excitation–contraction (E–C) coupling, depolarization of the plasma membrane triggers Ca2+ release from the sarcoplasmic reticulum (SR), referred to as depolarization-induced Ca2+ release (DICR). DICR occurs through the type 1 ryanodine receptor (RyR1), which physically interacts with the dihydropyridine receptor Cav1.1 subunit in specific machinery formed with additional essential components including β1a, Stac3 adaptor protein, and junctophilins. Exome sequencing has accelerated the discovery of many novel mutations in genes encoding DICR machinery in various skeletal muscle diseases. However, functional validation is time-consuming because it must be performed in a skeletal muscle environment. In this study, we established a platform of the reconstituted DICR in HEK293 cells. The essential components were effectively transduced into HEK293 cells expressing RyR1 using baculovirus vectors, and Ca2+ release was quantitatively measured with R-CEPIA1er, a fluorescent ER Ca2+ indicator, without contaminant of extracellular Ca2+ influx. In these cells, [K+]-dependent Ca2+ release was triggered by chemical depolarization with the aid of inward rectifying potassium channel, indicating a successful reconstitution of DICR. Using the platform, we evaluated several Cav1.1 mutations that are implicated in malignant hyperthermia and myopathy. We also tested several RyR1 inhibitors; whereas dantrolene and Cpd1 inhibited DICR, procaine had no effect. Furthermore, twitch potentiators such as perchlorate and thiocyanate shifted the voltage dependence of DICR to more negative potentials without affecting Ca2+-induced Ca2+ release. These results well reproduced the findings with the muscle fibers and the cultured myotubes. Since the procedure is simple and reproducible, the reconstituted DICR platform will be highly useful for the validation of mutations and drug discovery for skeletal muscle diseases.

L-type CaElectrophysiological recordings, CaS-nitrosylation significantly reduced the CaThis study provides strong evidence that S-nitrosylation-mediated downregulation of Ca

Cardiac autonomic dysfunction (CADF) is a major contributor to increased cardiac mortality in schizophrenia patients. The aberrant function of voltage-gated ion channels, which are widely distributed in the brain and heart, may link schizophrenia and CADF. In search of channel-encoding genes that are associated with both CADF and schizophrenia,First, we searched the literature for single-nucleotide polymorphisms (SNPs) inWe observed significantly increased QTvi in unmedicated patients with CADF-associated risk inWe propose a potential pleiotropic role for common variation in

Previous studies have demonstrated that brain-derived neurotrophic factor (BDNF) is one of the diffusible messengers for enhancing synaptic transmission in the hippocampus. Less information is available about the possible roles of BDNF in the anterior cingulate cortex (ACC). In the present study, we used 64-electrode array field recording system to investigate the effect of BDNF on ACC excitatory transmission. We found that BDNF enhanced synaptic responses in a dose-dependent manner in the ACC in C57/BL6 mice. The enhancement was long-lasting, and persisted for at least 3 h. In addition to the enhancement, BDNF also recruited inactive synaptic responses in the ACC. Bath application of the tropomyosin receptor kinase B (TrkB) receptor antagonist K252a blocked BDNF-induced enhancement. L-type voltage-gated calcium channels (L-VGCC), metabotropic glutamate receptors (mGluRs), but not NMDA receptors were required for BDNF-produced enhancement. Moreover, calcium-stimulated adenylyl cyclase subtype 1 (AC1) but not AC8 was essential for the enhancement. A selective AC1 inhibitor NB001 completely blocked the enhancement. Furthermore, BDNF-produced enhancement occluded theta burst stimulation (TBS) induced long-term potentiation (LTP), suggesting that they may share similar signaling mechanisms. Finally, the expression of BDNF-induced enhancement depends on postsynaptic incorporation of calcium-permeable AMPA receptors (CP-AMPARs) and protein kinase Mζ (PKMζ). Our results demonstrate that cortical BDNF may contribute to synaptic potentiation in the ACC.