Content area
Full text
Ion channels are precisely organized and play a crucial role in dynamic signaling, which is often unique to the animal kingdom.
Abstract
Charged ions and ion channels play a critical role in regulating the electrical activities of excitable cells. This review discusses the principles of ion channel regulation in the time domain, as well as the diseases that can arise from channel dysfunction and disturbances in ionic balance. Ion channel signaling is a dynamic process that is essential for various physiological functions, including pain sensation, motor control, and the body's response to stress, such as fight-or-flight response.
Introduction
Ion channels are membrane proteins that create subnanometer-diameter pores that allow specific ions to permeate the cell membrane.1 More than 300 types of ion channel genes have been identified in the human genome, and dysfunctions in these channels, known as channelopathies, are implicated in a wide range of diseases. They are also an important drug target, with numerous therapeutics designed to modulate their activity. Channel regulation is mediated by a wide range of physiological stimuli, including transmembrane voltage, temperature, neurotransmitters, and mechanical force. Recent research has revealed that membrane lipids and lipid-bilayer structures also play a key role in modulating channel function and electrical excitability, allowing for fine-tuning of channel activity during complex physiological responses.
The Roles of Ion Channels: from Nerve Impulses to Cystic Fibrosis
Ionic fluxes from voltage-activated sodium (Na+) and potassium (K+) channels establish the rise and fall of action potentials, commonly referred to as "nerve impulses" or "spikes" (Figure 1). These impulses are crucial to nearly all physiological processes. They underlie the transmission of information between neurons, allowing us to perceive the world around us, and to think. Furthermore, ion channels are essential to the function of other excitable cells, such as muscle cells. In muscle cells, action potentials are responsible for the contraction of muscles, allowing us to move and exert force.
Apart from the channels that shape nerve impulses, there are other channels that are well-known to medical doctors. These channels include the renal outer medullary K+ channel (ROMK) that secretes potassium in the collecting duct system of the kidney, the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels that controls epithelial mucus transport in the lung, the calcium-activated K+...