Key regulator in brain, heart's pacemakers discovered

Scientists have discovered an outer shield over T-type channels that change the electrochemical signaling of heart and brain cells.

Scientists have claimed that understanding how these shields work will help researchers eventually develop a new class of drugs for treating epilepsy, cardiovascular disease and cancer.

According to the study from the University of Waterloo, T-type channels in the pond snail, Lymnaea stagnalis, can shift from using calcium ions to using sodium ions to generate the electrical signal because of an outer shield of amino acids called a turret situated above the channel's entrance.

The study revealed that low voltage T-type channels generate tiny pulses of current at regular intervals by selectively passing positively charged cations across the cell's membrane through a gate-like channel and the channels are normally extremely selective, allowing just one sodium ion to pass for every 10,000 calcium ions.

The resulting rhythmic signals produced by this transfer of cations are what support the synchronous contraction of our heart muscles and neuronal firing in parts of the brain, like the thalamus, which helps regulate our sleep-wake cycle, or circadian rhythm.

David Spafford said that they wanted to understand the molecular structures of T-type channels and how they pass ionic currents to generate electrical activity, and to identify drug binding sites, and the drugs which may block these channels to treat neurological disease or heart complications.

The study was published in the Journal of Biological Chemistry.