{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T00:25:31Z","timestamp":1792628731305,"version":"4.5.0"},"reference-count":35,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T00:00:00Z","timestamp":1759363200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pharmacol."],"abstract":"<jats:p>This study highlights the complementarity of automated patch-clamp (APC) and manual patch-clamp (MPC) approaches to describe the electrophysiological properties of eighteen Ca<jats:sub>v<\/jats:sub>3.1 calcium channel variants associated with various neurological conditions. Current density was measured efficiently for all variants in APC experiments, with four variants (p.V184G, p.N1200S, p.S1263A and p.D2242N) showing elevated current densities, compared to wild-type Ca<jats:sub>v<\/jats:sub>3.1 channel, while six variants (p.M197R, p.V392M, p.F956del, p.I962N, p.I1412T, and p.G1534D) displayed reduced current densities, and were therefore preferentially studied using MPC. The electrophysiological properties were well preserved in APC (e.g., inactivation and deactivation kinetics, steady-state properties), with only the APC-MPC correlation for activation kinetics being less robust. In addition, neuronal modeling, using a deep cerebellar neuron (DCN) environment, revealed that most of the variants localized to the intracellular gate (S5 and S6 segments) could increase DCN spike frequencies. This DCN firing was highly dependent on current density and further pointed to the gain-of-function (GOF) properties of p.A961T and p.M1531V, the two recurrent variants associated with Spinocerebellar Ataxia type-42 with Neurodevelopmental Deficit (SCA42ND). Action-potential (AP) clamp experiments performed using cerebellar and thalamic neuron activities further established the GOF properties of p.A961T and p.M1531V variants. Overall, this study demonstrates that APC is well-suited for high-throughput analysis of Ca<jats:sub>v<\/jats:sub>3.1 channel variants, and that MPC complements APC for characterizing low-expression variants. Furthermore, <jats:italic>in silico<\/jats:italic> modeling and AP clamp experiments reveal that the gain- or loss-of-function properties of the variants are determined by how the Ca<jats:sub>v<\/jats:sub>3.1 channel decodes the electrophysiological context of a neuron.<\/jats:p>","DOI":"10.3389\/fphar.2025.1613072","type":"journal-article","created":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T05:35:09Z","timestamp":1759383309000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Electrophysiological classification of CACNA1G gene variants associated with neurodevelopmental and neurological disorders"],"prefix":"10.3389","volume":"16","author":[{"given":"Ama\u00ebl","family":"Davakan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leos","family":"Cmarko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barbara","family":"Ribeiro Oliveira-Mendes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claire","family":"Bernat","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Najlae","family":"Boulali","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00e9r\u00f4me","family":"Montnach","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephanie E.","family":"Vallee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mary B.","family":"Dinulos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lydie","family":"Burglen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincent","family":"Cantagrel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Norbert","family":"Weiss","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophie","family":"Nicole","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arnaud","family":"Monteil","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"De Waard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philippe","family":"Lory","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,10,2]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"681","DOI":"10.1007\/s12311-010-0224-3","article-title":"Controlling Ca2+-activated K+ channels with models of Ca2+ buffering in Purkinje cells","volume":"11","author":"Anwar","year":"2012","journal-title":"Cerebellum"},{"key":"B2","doi-asserted-by":"publisher","first-page":"1839","DOI":"10.1093\/brain\/awab443","article-title":"Analysing an allelic series of rare missense variants of CACNA1I in a Swedish schizophrenia cohort","volume":"145","author":"Baez-Nieto","year":"2022","journal-title":"Brain"},{"key":"B3","doi-asserted-by":"publisher","first-page":"6333","DOI":"10.3390\/ijms21176333","article-title":"Novel missense CACNA1G mutations associated with infantile-onset developmental and epileptic encephalopathy","volume":"21","author":"Berecki","year":"2020","journal-title":"Int. J. Mol. Sci."},{"key":"B4","doi-asserted-by":"publisher","first-page":"13705","DOI":"10.1073\/pnas.1511740112","article-title":"Phosphorylation of the Cav3.2 T-type calcium channel directly regulates its gating properties","volume":"112","author":"Blesneac","year":"2015","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"B5","doi-asserted-by":"publisher","first-page":"e22331","DOI":"10.7554\/eLife.22331","article-title":"Activity-dependent regulation of T-type calcium channels by submembrane calcium ions","volume":"21","author":"Cazade","year":"2017","journal-title":"Elife"},{"key":"B6","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1113\/jphysiol.2001.013269","article-title":"Specific contribution of human T-type calcium channel isotypes (alpha(1G), alpha(1H) and alpha(1I)) to neuronal excitability","volume":"540","author":"Chemin","year":"2002","journal-title":"J. Physiol."},{"key":"B7","doi-asserted-by":"publisher","first-page":"1998","DOI":"10.1093\/brain\/awy145","article-title":"De novo mutation screening in childhood-onset cerebellar atrophy identifies gain-of-function mutations in the CACNA1G calcium channel gene","volume":"141","author":"Chemin","year":"2018","journal-title":"Brain"},{"key":"B8","doi-asserted-by":"publisher","first-page":"726","DOI":"10.1016\/j.ajhg.2015.09.007","article-title":"A recurrent mutation in CACNA1G alters Cav3.1 T-type calcium-channel conduction and causes autosomal-dominant cerebellar ataxia","volume":"97","author":"Coutelier","year":"2015","journal-title":"Am. J. Hum. Genet."},{"key":"B9","doi-asserted-by":"publisher","first-page":"169","DOI":"10.1523\/JNEUROSCI.16-01-00169.1996","article-title":"In vivo, in vitro, and computational analysis of dendritic calcium currents in thalamic reticular neurons","volume":"16","author":"Destexhe","year":"1996","journal-title":"J. Neurosci."},{"key":"B10","doi-asserted-by":"publisher","first-page":"199","DOI":"10.24875\/RIC.20000380","article-title":"Ethical considerations in animal research: the principle of 3R's","volume":"73","author":"Diaz","year":"2020","journal-title":"Rev. Invest Clin."},{"key":"B11","doi-asserted-by":"publisher","first-page":"2092","DOI":"10.1093\/brain\/awab101","article-title":"CACNA1I gain-of-function mutations differentially affect channel gating and cause neurodevelopmental disorders","volume":"144","author":"El Ghaleb","year":"2021","journal-title":"Brain"},{"key":"B12","doi-asserted-by":"publisher","first-page":"111","DOI":"10.1016\/j.ajhg.2020.05.015","article-title":"High-throughput reclassification of SCN5A variants","volume":"107","author":"Glazer","year":"2020","journal-title":"Am. J. Hum. Genet."},{"key":"B13","doi-asserted-by":"publisher","first-page":"1179","DOI":"10.1162\/neco.1997.9.6.1179","article-title":"The NEURON simulation environment","volume":"9","author":"Hines","year":"1997","journal-title":"Neural comput."},{"key":"B14","doi-asserted-by":"publisher","first-page":"3804","DOI":"10.1523\/JNEUROSCI.12-10-03804.1992","article-title":"A novel T-type current underlies prolonged Ca(2+)-dependent burst firing in GABAergic neurons of rat thalamic reticular nucleus","volume":"12","author":"Huguenard","year":"1992","journal-title":"J. Neurosci."},{"key":"B15","doi-asserted-by":"publisher","first-page":"1199","DOI":"10.1016\/j.ajhg.2022.05.002","article-title":"A calibrated functional patch-clamp assay to enhance clinical variant interpretation in KCNH2-related long QT syndrome","volume":"109","author":"Jiang","year":"2022","journal-title":"Am. J. Hum. Genet."},{"key":"B16","doi-asserted-by":"publisher","first-page":"504","DOI":"10.1038\/ng.3789","article-title":"Refining the role of de novo protein-truncating variants in neurodevelopmental disorders by using population reference samples","volume":"49","author":"Kosmicki","year":"2017","journal-title":"Nat. Genet."},{"key":"B17","doi-asserted-by":"publisher","first-page":"249","DOI":"10.1111\/j.1748-1716.2006.01539.x","article-title":"Gating of the expressed T-type Cav3.1 calcium channels is modulated by Ca2+","volume":"186","author":"Lacinov\u00e1","year":"2006","journal-title":"Acta Physiol. (Oxf)"},{"key":"B18","doi-asserted-by":"publisher","first-page":"831","DOI":"10.1007\/s00424-020-02429-7","article-title":"Neuronal Cav3 channelopathies: recent progress and perspectives","volume":"472","author":"Lory","year":"2020","journal-title":"Pflugers Arch."},{"key":"B19","doi-asserted-by":"publisher","first-page":"738260","DOI":"10.3389\/fphar.2021.738260","article-title":"An advanced automated patch clamp protocol design to investigate drug-ion channel binding dynamics","volume":"12","author":"Lukacs","year":"2021","journal-title":"Front. Pharmacol."},{"key":"B20","doi-asserted-by":"publisher","first-page":"1294741","DOI":"10.3389\/fphys.2023.1294741","article-title":"Development of automated patch clamp assays to overcome the burden of variants of uncertain significance in inheritable arrhythmia syndromes","volume":"14","author":"Ma","year":"2023","journal-title":"Front. Physiol."},{"key":"B21","doi-asserted-by":"publisher","first-page":"e004569","DOI":"10.1161\/CIRCGEN.124.004569","article-title":"Multisite validation of a functional assay to adjudicate SCN5A Brugada syndrome-associated variants","volume":"17","author":"Ma","year":"2024","journal-title":"Circ. Genom Precis. Med."},{"key":"B22","doi-asserted-by":"publisher","first-page":"3282","DOI":"10.1038\/s41598-021-82077-8","article-title":"Computer modeling of whole-cell voltage-clamp analyses to delineate guidelines for good practice of manual and automated patch-clamp","volume":"11","author":"Montnach","year":"2021","journal-title":"Sci. Rep."},{"key":"B23","doi-asserted-by":"publisher","first-page":"bpab003","DOI":"10.1093\/biomethods\/bpab003","article-title":"Heterozygous KCNH2 variant phenotyping using Flp-In HEK293 and high-throughput automated patch clamp electrophysiology","volume":"6","author":"Ng","year":"2021","journal-title":"Biol. Methods Protoc."},{"key":"B24","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1113\/JP282107","article-title":"The suitability of high throughput automated patch clamp for physiological applications","volume":"600","author":"Obergrussberger","year":"2022","journal-title":"J. Physiol."},{"key":"B25","doi-asserted-by":"publisher","first-page":"e1266","DOI":"10.1002\/ctm2.1266","article-title":"Predicting hERG repolarization power at 37 \u00b0C from recordings at room temperature","volume":"13","author":"Oliveira-Mendes","year":"2023","journal-title":"Clin. Transl. Med."},{"key":"B26","doi-asserted-by":"publisher","first-page":"117","DOI":"10.1152\/physrev.00018.2002","article-title":"Molecular physiology of low-voltage-activated t-type calcium channels","volume":"83","author":"Perez-Reyes","year":"2003","journal-title":"Physiol. Rev."},{"key":"B27","doi-asserted-by":"publisher","first-page":"101337","DOI":"10.1016\/j.gim.2024.101337","article-title":"The characterization of new de novo CACNA1G variants affecting the intracellular gate of Cav3.1 channel broadens the spectrum of neurodevelopmental phenotypes in SCA42ND","volume":"27","author":"Qebibo","year":"2024","journal-title":"Genet. Med."},{"key":"B28","doi-asserted-by":"publisher","first-page":"4517","DOI":"10.1523\/JNEUROSCI.17-12-04517.1997","article-title":"Resurgent sodium current and action potential formation in dissociated cerebellar Purkinje neurons","volume":"17","author":"Raman","year":"1997","journal-title":"J. Neurosci."},{"key":"B29","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1016\/j.pediatrneurol.2022.11.003","article-title":"Paroxysmal tonic Upgaze in a patient with congenital ataxia due to a de novo missense variant of CACNA1G","volume":"139","author":"Riquet","year":"2023","journal-title":"Pediatr. Neurol."},{"key":"B30","doi-asserted-by":"publisher","first-page":"e1004641","DOI":"10.1371\/journal.pcbi.1004641","article-title":"Cerebellar nuclear neurons Use time and rate Coding to transmit Purkinje neuron Pauses","volume":"11","author":"Sudhakar","year":"2015","journal-title":"PLoS Comput. Biol."},{"key":"B31","doi-asserted-by":"publisher","first-page":"383","DOI":"10.1016\/bs.mie.2021.02.011","article-title":"Functional evaluation of human ion channel variants using automated electrophysiology","volume":"654","author":"Vanoye","year":"2021","journal-title":"Methods Enzymol."},{"key":"B32","doi-asserted-by":"publisher","first-page":"e156314","DOI":"10.1172\/jci.insight.156314","article-title":"High-throughput evaluation of epilepsy-associated KCNQ2 variants reveals functional and pharmacological heterogeneity","volume":"7","author":"Vanoye","year":"2022","journal-title":"JCI Insight"},{"key":"B33","doi-asserted-by":"publisher","first-page":"87","DOI":"10.2174\/1875397301206010087","article-title":"A comparison of the performance and application differences between manual and automated patch-clamp techniques","volume":"6","author":"Yajuan","year":"2012","journal-title":"Curr. Chem. Genomics"},{"key":"B34","doi-asserted-by":"publisher","first-page":"821","DOI":"10.1124\/pr.114.009654","article-title":"The physiology, Pathology, and pharmacology of voltage-gated calcium channels and their future therapeutic potential","volume":"67","author":"Zamponi","year":"2015","journal-title":"Pharmacol. Rev."},{"key":"B35","doi-asserted-by":"publisher","first-page":"492","DOI":"10.1038\/s41586-019-1801-3","article-title":"Cryo-EM structures of apo and antagonist-bound human Ca(v)3.1","volume":"576","author":"Zhao","year":"2019","journal-title":"Nature"}],"container-title":["Frontiers in Pharmacology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphar.2025.1613072\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T05:35:09Z","timestamp":1759383309000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphar.2025.1613072\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,2]]},"references-count":35,"alternative-id":["10.3389\/fphar.2025.1613072"],"URL":"https:\/\/doi.org\/10.3389\/fphar.2025.1613072","relation":{},"ISSN":["1663-9812"],"issn-type":[{"value":"1663-9812","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,2]]},"article-number":"1613072"}}