Ca2+ -activated Cl- channels control electrical excitability in various peripheral and central populations of neurons. Ca2+ influx through voltage-gated or ligand-operated channels, as well as Ca2+ release from intracellular stores, have been shown to induce substantial Cl- conductances that determine the response to synaptic input, spike rate, and the receptor current of various kinds of neuro...

Airway smooth muscle tone is ultimately generated by phosphorylation of myosin light chain, which is regulated by the balance between concentrations of Ca2+ and sensitivity to Ca2+ in the cytosolic side. The former is due to the Ca2+ influx passing through ion channels (Ca2+ dynamics), leading to activation of myosin light chain kinase, and the latter is due to Rho-kinase (Ca2+ sensitization), ...

Ca2+-activated K+ currents and their Ca2+ sources through high-threshold voltage-activated Ca2+ channels were studied using whole-cell patch-clamp recordings from freshly dissociated mouse neocortical pyramidal neurons. In the presence of 4-aminopyridine, depolarizing pulses evoked transient outward currents and several components of sustained currents in a subgroup of cells. The fast transient...

Ca2+ channels allow passage of Ca2+ ions into the cytoplasm through a selective pore which is opened in response to depolarization of the cell membrane (for reviews see Hagiwara & Byerly, 1981, 1983; Tsien, 1983; Reuter, 1983). The Ca2+ flux creates a net inward, depolarizing current and the resulting accumulation of Ca2+ in the cytoplasm can act as a chemical trigger for secretion of hormones ...

Presynaptic N-type Ca2+ channels (CaV2.2, alpha1B) are thought to bind to SNARE (SNAP-25 receptor) complex proteins through a synaptic protein interaction (synprint) site on the intracellular loop between domains II and III of the alpha1B subunit. Whether binding of syntaxin to the N-type Ca2+ channels is required for coupling Ca2+ ion influx to rapid exocytosis has been the subject of consider...

Hearing relies on faithful sound coding at hair cell ribbon synapses, which use Ca2+-triggered glutamate release to signal with submillisecond precision. Here, we investigated stimulus-secretion coupling at mammalian inner hair cell (IHC) synapses to explore the mechanisms underlying this high temporal fidelity. Using nonstationary fluctuation analysis on Ca2+ tail currents, we estimate that IH...

Cyclic nucleotide-gated channels are important in visual and olfactory transduction, and possibly in other neuronal functions. These channels have a complex permeability to Ca2+ ions that may be important in their cellular functions. They are composed of two different subunits, alpha and beta, that have been cloned and expressed, but the beta subunit alone cannot be activated by cyclic nucleoti...

Ca2+ entry into airway epithelia is important for activation of the NFAT family of transcription factors and expression of genes including epidermal growth factor that help orchestrate local inflammatory responses. However, the identity of epithelial Ca2+ channel that activates these transcriptional responses is unclear. In many other non-excitable cells, store-operated Ca2+ entry is a major ro...

407 The electrophysiological and pharmacological diversity of native calcium (Ca2+) channels (L, N, P, Q and T types) is well documented1. These subtypes have different functions; low-voltageactivated T-type channels shape action potentials and generate firing patterns2, whereas L-type channels regulate Ca2+-dependent genes and enzymes3,4, and N-type and P/Q-type channels contribute to neurotra...

The modulation of calcium channels by metabotropic glutamate receptors (mGluRs) is a key event in the fine-tuning of neurotransmitter release. Here we report that, in cerebrocortical nerve terminals of adult rats, the inhibition of glutamate release is mediated by mGluR7. In this preparation, the major component of glutamate release is supported by P/Q-type Ca2+ channels (72.7%). However, mGluR...