Inhibitory synaptic transmission between leech heart interneurons consist of two components: graded, gated by Ca2+ entering by low-threshold [low-voltage-activated (LVA)] Ca channels and spike-mediated, gated by Ca2+ entering by high-threshold [high-voltage-activated (HVA)] Ca channels. Changes in presynaptic background Ca2+ produced by Ca2+ influx through LVA channels modulate spike-mediated t...

Voltage-sensitive cation-selective ion channels of the voltage-gated ion channel (VGC) superfamily were examined by a combination of sequence alignment and phylogenetic tree construction procedures. Segments of the alpha-subunits of K+-selective channels homologous to the structurally elucidated KcsA channel of Streptomyces lividans were multiply aligned, and this alignment provided the databas...

Problem statement: Epilepsy is a common neurological disorder that afflicts 1-2% of the general population worldwide. It encompasses a variety of disorders with seizures. Approach: Idiopathic epilepsies were defined as a heterogeneous group of seizure disorders that show no underlying cause .Voltage-gated ion channels defect were recognized etiology of epilepsy in the central nervous system. Th...

Genes encoding the α subunits of neuronal sodium channels have evolutionarily conserved sites of alternative splicing but no functional differences have been attributed to the splice variants. Here, using Na(V)1.7 as an exemplar, we show that the sodium channel isoforms are functionally distinct when co-expressed with β subunits. The gene, SCN9A, encodes the α subunit of the Na(V)1.7 channel, a...

Gain-of-function mutations or dysregulated expression of voltage-gated sodium channels can produce neuronal hyperexcitability, leading to acute or chronic pain. The sodium channel Na(v)1.7 is expressed preferentially in most slowly conducting nociceptive neurons and in sympathetic neurons. Gain-of-function mutations in the Na(v)1.7 channel lead to DRG neuron hyperexcitability associated with se...

Scorpion α-toxins bind to the voltage-sensing domains of voltage-gated sodium (Na(V)) channels and interfere with the inactivation mechanisms. The functional surface of α-toxins has been shown to contain an NC-domain consisting of the five-residue turn (positions 8-12) and the C-terminus (positions 56-64) and a core-domain centered on the residue 18. The NC- and core-domains are interconnected ...

showed that local circuit currents from an excited region Our ability todo gymnastics, to perceive a colorful world, of nerve are needed to bring the next region into activity. and to process language relies on rapid communication This meant that depolarization is the natural stimulus among neurons. Such signaling, the fastest in our bodfor action potential propagation. J. Z. Young (1936) reies...

showed that local circuit currents from an excited region Our ability todo gymnastics, to perceive a colorful world, of nerve are needed to bring the next region into activity. and to process language relies on rapid communication This meant that depolarization is the natural stimulus among neurons. Such signaling, the fastest in our bodfor action potential propagation. J. Z. Young (1936) reies...

Because of their fundamental role in generating electrical impulses in many excitable tissues, sodium channels were among the first voltage-gated ion channels to be extensively investigated. Neurons bathed in a physiological solution containing 150 mM sodium ions respond to a threshold electrical stimulus by generating an action potential, whereas such a response is abolished in a Na+-free medi...

Voltage-gated sodium (Na(v)) channels accumulate at the axon initial segment (IS), where their high density supports spike initiation. Maintenance of this high density of Na(v) channels involves a macromolecular complex that includes the cytoskeletal linker protein ankyrin-G, the only protein known to bind Na(v) channels and localize them at the IS. We found previously that Na(v)1.6 is the pred...