Biomechanical activation and subcellular force adaptation in the peripheral mechanosensory system

The senses of hearing and touch first rely on forces activating specialized primary mechanosensors, then on neurons transmitting encodings of these forces to the brain. We would like to understand how environmental forces impinge on mechanically sensitive structures, and how these forces act within cells to drive neural responses. However, delivering precise mechanical stimulation while recording responses has proven difficult due to mechanosensor inaccessibility.

To overcome this limitation, we established approaches in the fruit fly antennal mechanosensory organ for recording mechanosensor mechanics and neural responses in situ. Mechanical stimuli drive the antenna to rotate, in turn activating its 200 mechanosensors. By precisely manipulating antennal position, we can simultaneously stimulate all antennal mechanosensors. Using laser microdissection to expose the organ, we can track cellular structures with 2-photon microscopy to understand force transmission into mechanosensors, and record single-neuron activity with patch-clamp electrophysiology to understand neural tuning to these forces. This has enabled both understanding of organ-level mechanical function, and, with genetic approaches, dissection of molecular contributions to mechanosensory responses.