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Voltage-gated sodium channels (NaCh) are colocalized with isoforms of the membrane-skeletal protein ankyrinG at axon initial segments, nodes of Ranvier, and postsynaptic folds of the mammalian neuromuscular junction. The role of ankyrinG in directing NaCh localization to axon initial segments was evaluated by region-specific knockout of ankyrinG in the(More)
Inhibition of Ca channel current by luteinizing hormone-releasing hormone (LHRH) was studied in freshly dissociated bullfrog sympathetic ganglion neurons using whole-cell recording. LHRH inhibited up to 80% of the high-threshold Ca channel current with a half-maximally effective concentration of about 20 nM. LHRH inhibited omega-conotoxin-sensitive but not(More)
Inhibition of voltage-dependent calcium channels by omega-conotoxin MVIIC (omega-CTx-MVIIC) was studied in various types of rat neurons. When studied with 5 mM Ba2+ as charge carrier, omega-CTx-MVIIC block of N-type calcium channels in sympathetic neurons was potent, with half-block at 18 nM. Block of N-type channels had a rapid onset (tau approximately 1(More)
Block of N-type Ca channels by omega-conotoxin GVIA (CgTx) was studied in freshly dissociated bullfrog and rat sympathetic neurons. With 2-5 mM Ba as charge carrier, CgTx blocked almost all of the high-threshold Ca channel current recorded in the presence of nimodipine (3 microM) to block L-type Ca channels. Toxin block reversed slowly (time constant(More)
A number of peptide toxins from venoms of spiders and cone snails are high affinity ligands for voltage-gated calcium channels and are useful tools for studying calcium channel function and structure. Using whole-cell recordings from rat sympathetic ganglion and cerebellar Purkinje neurons, we studied toxins that target neuronal N-type (Ca(V)2.2) and P-type(More)
1. We studied the gating kinetics of Kv4.2 channels, the molecular substrate of neuronal somatodendritic A-type currents. For this purpose wild-type and mutant channels were transiently expressed in the human embryonic kidney (HEK) 293 cell line and currents were measured in the whole-cell patch-clamp configuration. 2. Kv4.2 channels inactivated from(More)
The regulation by protein kinase C (PKC) of recombinant voltage-gated potassium (K) channels in frog oocytes was studied. Phorbol 12-myristate 13-acetate (PMA; 500 nM), an activator of PKC, caused persistent and large (up to 90%) inhibition of mouse, rat, and fly Shaker K currents. K current inhibition by PMA was blocked by inhibitors of PKC, and inhibition(More)
The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid-beta protein (Abeta), which forms amyloid plaques in Alzheimer's disease (AD), secreted APPalpha (sAPPalpha) which enhances memory, and the APP intracellular domain (AICD), which has been implicated in the regulation of gene(More)
The gating of Ca2+-activated Cl− channels is controlled by a complex interplay among [Ca2+]i, membrane potential and permeant anions. Besides Ca2+, Ba2+ also can activate both TMEM16A and TMEM16B. This study reports the effects of several divalent cations as regulators of TMEM16A channels stably expressed in HEK293T cells. Among the divalent cations that(More)
The inhibitory and excitatory amino acid neurotransmitter receptors in the mammalian central nervous system mediate functionally opposite synaptic responses yet appear to share certain structural features. Recent conceptual advances in this field have relied heavily on information obtained by single channel analyses, by the expression of receptors in(More)