The aim of this work was to characterize several ionic channels in nervous cells of the suboesophageal visceral, left and right parietal, and left and right pleural brain ganglia complex of the snail Helix aspersa by immunocytochemistry. We have studied the immunostaining reaction for a wide panel of eleven polyclonal antibodies raised against mammal antigens as follows: voltage-gated-Na+ chann...

In excitable cells, the main mediators of sodium conductance across membranes are voltage-gated sodium channels (Na(V)s). Eukaryotic Na(V)s are essential elements in neuronal signaling and muscular contraction and in humans have been causally related to a variety of neurological and cardiovascular channelopathies. They are complex heavily glycosylated intrinsic membrane proteins present in only...

Voltage-gated Na(+) channels are the workhorses of spike generation and propagation in excitable cells. Mutations in Na(+) channel genes have been identified in disorders causing episodic dysfunction of heart, skeletal muscle, and brain. Lossin and colleagues from Al George's lab report in this issue of Neuron that three missense mutations of SCN1A found in a dominant epilepsy syndrome disrupt ...

Panek I, Höger U, French AS, Torkkeli PH. Contributions of voltageand Ca -activated conductances to GABA-induced depolarization in spider mechanosensory neurons. J Neurophysiol 99: 1596–1606, 2008. First published January 23, 2008; doi:10.1152/jn.01267.2007. Activation of ionotropic -aminobutyric acid type A (GABAA) receptors depolarizes neurons that have high intracellular [Cl ], causing inhib...

To better understand how renal Na(+) reabsorption is altered by heavy metal poisoning, we examined the effects of several divalent heavy metal ions (Zn(2+), Ni(2+), Cu(2+), Pb(2+), Cd(2+), and Hg(2+)) on the activity of single epithelial Na(+) channels (ENaC) in a renal epithelial cell line (A6). None of the cations changed the single-channel conductance. However, ENaC activity [measured as the...

This review discusses recent data regarding the different types of voltage-gated Na+, Ca2+, and K+ channels in dendrites of CA1 pyramidal neurons and their function for synaptic integration and plasticity. Na+ and Ca2+ channels are uniformly distributed throughout the dendrites, although Na+ channels in the soma and proximal dendrites differ in their inactivation properties from Na+ channels in...

objective(s): recently, phthalimide derivatives were designed based on ameltolide and thalidomide as they possess a similar degree of anticonvulsant potency due to their phenytoin-like profile. the ability of phthalimide pharmacophore to interact with neuronal voltage-dependent sodium channels was studied in the batrachotoxin affinity assay. therefore, in the present study, a series of 19 compo...

Sodium channel inhibitor (SCI) insecticides selectively target voltage-gated sodium (Na(v)) channels in the slow-inactivated state by binding at or near the local anesthetic receptor within the sodium channel pore. Metaflumizone is a new insecticide for the treatment of fleas on domesticated pets and has recently been reported to block insect sodium channels in the slow-inactivated state, there...

The Ca(2+)-free form of calmodulin (apoCaM) often appears inert, modulating target molecules only upon conversion to its Ca(2+)-bound form. This schema has appeared to govern voltage-gated Ca(2+) channels, where apoCaM has been considered a dormant Ca(2+) sensor, associated with channels but awaiting the binding of Ca(2+) ions before inhibiting channel opening to provide vital feedback inhibiti...