Pharyngeal Mechanosensory Neurons Control Food Swallow inDrosophila melanogaster

Abstract

AbstractAs the first step of food ingestion, the swallow is under rigorous sensorimotor control. Nevertheless, the mechanisms underlying swallow control at a molecular and circuitry level remain largely unknown. Here, we find that mutation of the mechanotransduction channel genesnompC, Tmc, orpiezoimpairs the regular pumping rhythm of the cibarium during feeding of the fruit flyDrosophila melanogaster. A group of multi-dendritic mechanosensory neurons, which co-express the three channels, wrap the cibarium and are crucial for coordinating the filling and emptying of the cibarium. Inhibition of them causes difficulty in food emptying in the cibarium, while their activation leads to difficulty in cibarium filling. Synaptic and functional connections are detected between the pharyngeal mechanosensory neurons and the motor circuit that controls swallow. This study elucidates the role of mechanosensation in swallow, and provides insights for a better understanding of the neural basis of food swallow.HighlightsnompC+,piezo+andTmc+neurons in the pharynx sense mechanical force during swallowingPharyngeal mechanoreceptor neurons regulate swallow rhythmDysfunction of pharyngeal mechanosensory neurons causes dysphagiaPharyngeal mechanosensory neurons connect with brain motor neurons to coordinate swallow pattern