Changes of extracellular pH values can have profound effects on neuronal function. For example, the low pH (also called acidosis) generated in brain ischemia causes acute neuronal injury. For years the receptors that detect pH variations surrounding neurons and their physiological/pathological importance remain uncertain. The recent finding that acidosis activates a distinct family of membrane ...

Polyelectrolyte (PE) grafting on the solid-liquid interface of a nano-channel renders tremendous functionalities to the nano-channel. These grafted PE molecules attain "brush"-like configuration for large grafting density (σ), which makes the nano-channel (often denoted as soft nanochannel) capable of applications such as ion manipulation, ion sensing, current rectification, nano-fluidic diode ...

The expansion of polyglutamine tracts encoded by CAG trinucleotide repeats is a common mutational mechanism in inherited neurodegenerative diseases. Spinocerebellar ataxia type 6 (SCA6), an autosomal dominant, progressive disease, arises from trinucleotide repeat expansions present in the coding region of CACNA1A (chromosome 19p13). This gene encodes alpha(1A), the principal subunit of P/Q-type...

Acid-sensing ion channel 3 (ASIC3) is highly expressed on sensory neurons that innervate heart and skeletal muscle and, therefore, is proposed to detect lactic acidosis and to transduce angina and muscle ischemic pain. A difficulty with this idea is that ASIC3 rapidly desensitizes. How can a desensitizing ion channel mediate a persisting sensation such as angina? Here, we show that rat ASIC3 pr...

The gating modifier toxins are a large family of protein toxins that modify either activation or inactivation of voltage-gated ion channels. omega-Aga-IVA is a gating modifier toxin from spider venom that inhibits voltage-gated Ca(2+) channels by shifting activation to more depolarized voltages. We identified two Glu residues near the COOH-terminal edge of S3 in the alpha(1A) Ca(2+) channel (on...

A label-free optical sensor was constructed by integrating pH sensing material and supported phospholipid bilayers (SPBs) in a microfluidic chip. The pH sensing material was composed of a double layer structure consisting of chitosan hydrogel and electrochemically etched porous silicon. The pH change in the microchip could induce a reversible swelling of the chitosan hydrogel layer and conseque...

Amil: amiloride ASIC: acid-sensing ion channel GMQ: 2-guanidine-4-methylquinazoline EGTA: ethylene

Ion channels are naturally occurring pores through the proteins that regulate the passage of ions and thus maintain the concentration of ions inside and outside the cell. The ion channels control many physiological functions and they can show selectivity for a specific ion. Ion channels are mostly observed in nerve cells and muscle cells. The influx of ions into cells can be regulated by a gate...