A special issue on physiological aspects of mechanosensing

Mechanosensitivity: From Aristotle's sense of touch to cardiac mechano-electric coupling

Scientific interest in mechanosensation likely commenced with Aristotle's description of the sense of touch in his treatise de Anima [On the Soul]. Considering touch as a vital sense distributed over the whole body, the philosopher outlined a "physiological concept" at the macro-level already 2400 years ago. From this starting point, we outline the onset of modern sensory physiology during the early 19th century. Physiologists distinguished between outer and inner senses at that time, without, however, referring to specific receptors or nerves. We then outline how research on four topics concerning cardiac mechano-electric coupling developed up until the 1960's (cardio-respiratory coupling, Bainbridge reflex, Bezold-Jarisch reflex, stretch-induced arrhythmias). Following the discovery of macroscopic phenomena (e.g. change of heart rate, induced by atrial distension) during that period, researchers sought to identify the pertinent receptors and reflex loops, while nowadays the underlying subcellular mechanisms such as stretch-activated ion channels are under investigation.

Mechanisms of mechanosensing - mechanosensitive channels, function and re-engineering

Sensing and responding to mechanical stimuli is an ancient behavior and ubiquitous to all forms of life. One of its players 'mechanosensitive ion channels' are involved in processes from osmosensing in bacteria to pain in humans. However, the mechanism of mechanosensing is yet to be elucidated. This review describes recent developments in the understanding of a bacterial mechanosensitive channel. Force from the lipid principle of mechanosensation, new methods to understand protein-lipid interactions, the role of water in the gating, the use of engineered mechanosensitive channels in the understanding of the gating mechanism and application of the accumulated knowledge in the field of drug delivery, drug design and sensor technologies are discussed.