A mechanism for tuning proprioception proposed by research in Drosophila and mammals

Abstract

Proprioception provides important sensory feedback regarding the position of an animal’s body and limbs in space. This interacts with a central pattern generator responsible for rhythmic movement, to adapt locomotion to the demands that an animal’s environment places on it. The mechanisms by which this feedback is enabled are poorly understood, which belies its importance: dysfunctional proprioception is associated with movement disorder and improving it can help reduce the severity of symptoms. Similarly, proprioception is important for guiding accurate robotic movement and for understanding how sensory systems capture and process information to guide action selection. It is therefore important to interpret research that investigates mechanisms of proprioception, to ask: what type of information do proprioceptive sensors capture, and how do they capture it? Work in mammalian models has made important progress towards answering this question. So too, has research conducted Drosophila. Fruit fly proprioceptors are more accessible than mammalian equivalents and can be manipulated using a unique genetic toolkit, so experiments conducted in the invertebrate can make a significant contribution to overall understanding. It can be difficult, however, to relate work conducted in different models, to draw general conclusions about proprioception. This review, therefore, explores what research in the fruit fly has revealed about proprioceptor function, to highlight its potential translation to mammals. Specifically, the present text presents evidence that differential expression of mechanoelectrical transducers contributes to tuning of fly proprioceptors and suggests that the same mechanism may play a role in tuning mammalian proprioceptors.