Voltage-dependent calcium currents in Purkinje cells from rat cerebellar vermis.
Whole-cell patch clamp recording was used to characterize calcium currents in Purkinje cells dissociated from the cerebellar vermis of 1-3-week postnatal rats. A subset of Purkinje cells had a low-threshold, transient current similar to the T-type current in peripheral neurons. All Purkinje cells had a high-threshold, slowly inactivating current. Only a small component of the high-threshold current was sensitive to dihydropyridine (DHP) antagonists or to the dihydropyridine agonist BAY K8644. omega-Conotoxin had very little effect on the high-threshold current. The results suggest that these Purkinje cells have at least three types of calcium channels: T-type channels (present in only a fraction of cells), DHP-sensitive L-type channels (contributing a small fraction of the high-threshold current), and a predominant type of high-threshold channel that is pharmacologically distinct from L-type and N-type channels characterized in peripheral neurons.
Regan
L J
LJ
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115.
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001464:Barium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002469:Cell Separation; D004095:Dihydropyridines / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004553:Electric Conductivity; D004594:Electrophysiology; D009532:Nickel / Q000494:pharmacology; D009553:Nimodipine / Q000494:pharmacology; D009568:Nitrendipine / Q000494:pharmacology; D011689:Purkinje Cells / Q000166:cytology / Q000502:physiology*; D051381:Rats
D015220:Calcium Channels; D004095:Dihydropyridines; D001464:Barium; D009553:Nimodipine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D009532:Nickel; D009568:Nitrendipine