{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,5]],"date-time":"2025-10-05T16:53:06Z","timestamp":1759683186313},"reference-count":0,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[1995,2,1]],"date-time":"1995-02-01T00:00:00Z","timestamp":791596800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[1995,2]]},"abstract":"<jats:p>1. High\u2010threshold voltage\u2010gated calcium channel currents (IBa) were studied in cultured rat cerebellar granule neurones using the whole\u2010cell patch clamp technique with 10 mM Ba2+ as the charge carrier. The putative P\u2010type component of whole\u2010cell current was characterized by utilizing the toxin omega\u2010agatoxin IVA (omega\u2010Aga IVA) in combination with other blockers. 2. omega\u2010Aga IVA (100 nM) inhibited the high voltage\u2010activated (HVA) IBa by 40.9 +\/\u2010 3.4% (n = 27), and the dissociation constant Kd was 2.7 nM. Maximal inhibition occurred within a 2\u20103 min time course, and was irreversible. The isolated omega\u2010Aga IVA\u2010sensitive current was non\u2010inactivating. 3. omega\u2010Aga IVA exhibited overlapping selectivity with both N\u2010 and L\u2010channel blockers; omega\u2010conotoxin GVIA (omega\u2010CTX GVIA) (1 microM) and the dihydropyridine (\u2010)\u2010202\u2010709 (1 microM), respectively. Together these toxins reduced the omega\u2010Aga IVA\u2010sensitive component to just 4.5 +\/\u2010 1.4% (n = 3). Thus only a small proportion of the current can be unequivocally attributed to P\u2010type current. Inhibition of the HVA IBa by omega\u2010Aga IA also reduced the proportion of omega\u2010Aga IVA\u2010sensitive current to 28.0 +\/\u2010 3.2% (n = 3). 4. Application of omega\u2010Aga IVA and a synthetic form of funnel\u2010web toxin, N\u2010(7\u2010amino\u20104\u2010azaheptyl)\u2010L\u2010argininamide (sFTX\u20103.3; 10 microM), produced an additive block of the HVA IBa. Consequently these two toxins do not act on the same channel in cerebellar granule neurones. 5. omega\u2010Aga IVA inhibition of low voltage\u2010activated (LVA) IBa was studied in the ND7\u201023 neuronal cell line. omega\u2010Aga IVA (100 nM) reduced the LVA current by 41.3 +\/\u2010 3.2% (n = 17) in a fully reversible manner with no shift in the steady\u2010state inactivation of the channel. 6. A component of current insensitive to N\u2010, L\u2010 and P\u2010channel blockers remained unclassified in all our studies. This component, and also that remaining following block by omega\u2010Aga IVA and omega\u2010Aga IA, exhibited relatively rapid, although incomplete, inactivation compared to the other currents isolated in this study. 7. In conclusion, omega\u2010Aga IVA inhibits a component of current in cultured cerebellar granule neurones which overlaps almost completely with that inhibited by L\u2010 and N\u2010channel blockers. In addition, a large component of whole\u2010cell current in these neurones still remains unclassified.<\/jats:p>","DOI":"10.1113\/jphysiol.1995.sp020535","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T11:11:22Z","timestamp":1418814682000},"page":"493-509","source":"Crossref","is-referenced-by-count":73,"title":["Characterization of Ca2+ channel currents in cultured rat cerebellar granule neurones."],"prefix":"10.1113","volume":"482","author":[{"given":"H A","family":"Pearson","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K G","family":"Sutton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R H","family":"Scott","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A C","family":"Dolphin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1995,2]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1995.sp020535","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1995.sp020535","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T19:05:17Z","timestamp":1698347117000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1995.sp020535"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,2]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1995,2]]}},"alternative-id":["10.1113\/jphysiol.1995.sp020535"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1995.sp020535","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,2]]}}}