A special issue on physiological aspects of mechanosensing

Perception of mechanical stimuli is critically important for sensing the surrounding environment. As Aristotle pointed out in 350 BC (De Anima 3.12, 434b—1ff), all living organisms,frombacteriatomammals,relyonmechanosensationfor their survival. A unicellular paramecium, navigating its way through a chaotic environment, relies on mechanosensitive proteins to avoid obstacles. The cricket escapes the spider by possessingincredibly sensitivehairs,whichare abletopickup the faintest change in air flows. Crocodiles are dotted of thousands of highly sensitive mechanosensory receptors that enable them to sense the movement of their preys through vibrations in the water. Examples are endless in the animal kingdom. In humans, mechanosensation constitutes the physiological foundation for the senses of touch, pain, and hearing for regulation of multiple autonomic functions and for social exchange [4, 8–11]. Mechanosensation is ubiquitous in biological systems. Primary mechanosensitive processes have probably evolved as backup mechanisms for cell protection during osmotic swelling. Through evolutionary pressure, a number of mechanosensory structures have then emerged to accomplish a wide array of specialized tasks, ranging from cellular homeostasis to our ability of hearing and discriminative touch. Thus, mechanosensory structures exhibit some sort of homoplasy, all being specialized in the detection of force-related stimuli but arising from different evolutionary origins. The importanceof mechanosensoryinputsfor the existence of life justifies the effort made to understand its molecular origin(s). The basis for cell mechanosensation is a coupling of externalmechanicalforcestothechemicalreactionsthatoccur