Molecular Basis of Mechanosensitivity in Tactile Foraging Birds

Yale University, New Haven CT

Investigators

Abstract

Everything about the world surrounding organisms is perceived through senses. The sense of touch, or mechanosensitivity, is the ability to feel mechanical force through skin. Like the other senses, mechanosensitivity is vital for all aspects of everyday life in humans and other animals. It endows animals with the capacity to feel and explore the infinite richness of the tactile world. It is through mechanosensitivity that one perceives forces and textures that convey information about material properties, confer pain or evoke pleasure. Yet of all the senses that humans and other organisms possess, mechanosensitivity remains the least well understood from the cellular and molecular perspective. Only a very rudimentary understanding presently exists of how a breeze is felt and confidently identified, or how it is distinguished from a gentle touch, a blunt object or a mother's caress. This proposal seeks to shed light on the inner workings of mechanosensitivity, and then to disseminate this knowledge to schoolchildren. The results of this research will uncover fundamental principles of mechanosensitivity in vertebrates at the cellular and molecular level, and will be used further to incite interest in physiology in young audiences. The proposal will approach its scientific goals from an unconventional perspective: through studying mechanosensation in species which have taken the sense of touch to the extreme - tactile foraging ducks. It is well known that the ducks can find food in murky water relying almost exclusively on the sense of touch in their bill and tongue. These organs are richly innervated by mechanosensory nerve fibers, which originate in the trigeminal ganglia and terminate in microorgans analogous to the mammalian Meissner and Pacinian corpuscles. The proposal focuses on uncovering the molecular prerequisites that enable the mechanosensitive neurons to convert mechanical force into electrical impulses, which then propagate to the brain signaling a physical contact. To accomplish this, differential transcriptomics will be employed to single out molecules that are enriched in the mechanosensitive nerve fibers of tactile foraging birds. Each of the candidate molecules will undergo electrophysiological tests for the ability to detect mechanical contact. The end-goal of this proposal is to uncover the molecular machinery through which neurons sense mechanical stimulation. These results, along with other aspects of sensory physiology, will be made available to young audiences through the Sensory Physiology Club - an extracurricular initiative conceived by the researchers of this project to promote scientific education among schoolchildren.