Secretion of neurotransmitters is initiated by voltage-gated calcium influx through presynaptic, voltagegated N-type calcium channels. These channels interact with the SNARE proteins, which are core components of the exocytosis process, via the synaptic protein interaction (synprint) site in the intracellular loop connecting domains II and III of their a1B subunit. Interruption of this interact...

213 Abstract: The aim of the present study was to investigate the role of the L-type voltage dependent Ca2+ channel blocker, nimodipine, in kainate induced toxicity in retinal ganglion cells of mice. Kainate in 10mg/kg was administered intraperitoneally following the vehicle or nimodipine. Nimodipine, 45 minutes prior to kainate in 10, 15, 25, 50, 100 and 250 mg/kg doses was administered intrap...

The regulation of presynaptic, voltage-gated calcium channels by activation of heptahelical G protein-coupled receptors exerts a crucial influence on presynaptic calcium entry and hence on neurotransmitter release. Receptor activation subjects presynaptic N- and P/Q-type calcium channels to a rapid, membrane-delimited inhibition-mediated by direct, voltage-dependent interactions between G prote...

The ␣ 1E clone has been put forward as a possible candidate for T-type current because it possesses some of the salient features, including low activation voltage, rapid inactivation, and similar or greater whole-cell current amplitude in Ca 2ϩ compared to Ba 2ϩ (Soong et al., 1993). Nevertheless, major discrepancies exist, the main Summary one being that the single channel conductance reported...

The pedunculopontine nucleus (PPN) is a component of the reticular activating system (RAS), and is involved in the activated states of waking and rapid eye movement (REM) sleep. Gamma oscillations (approximately 30-80 Hz) are evident in all PPN neurons and are mediated by high-threshold voltage-dependent N- and P/Q-type calcium channels. We tested the hypothesis that high-speed calcium imaging ...

Calcium sparks represent local, rapid, and transient calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial smooth muscle cells (SMCs), calcium sparks activate calcium-dependent potassium channels causing decrease in the global intracellular [Ca2+] and oppose vasoconstriction. This is in contrast to cardiac and skeletal muscle, where spati...

Dopamine-releasing neurons of the substantia nigra pars compacta produce an extraordinarily dense and expansive plexus of innervation in the striatum converging with glutamatergic corticostriatal and thalamostriatal axon terminals at dendritic spines of medium spiny neurons. Here, we investigated whether glutamatergic signaling promotes arborization and growth of dopaminergic axons. In postnata...

L-type voltage-gated calcium channels (LTCs) may control neuronal gene expression by increasing nuclear Ca(2+) levels or regulating Ca(2+)/calmodulin-dependent transcription factors. In the November 3 issue of Cell, Gomez-Ospina et al. demonstrate another signaling mechanism, in which a C-terminal fragment of LTC translocates to the nucleus in a calcium-dependent manner and directly regulates t...

In T lymphocytes, calcium ion controls a variety of biological processes including development, survival, proliferation, and effector functions. These distinct and specific roles are regulated by different calcium signals, which are generated by various plasma membrane calcium channels. The repertoire of calcium-conducting proteins in T lymphocytes includes store-operated CRAC channels, transie...