The research objective of this award is to understand how neurons develop mechanical force (tension), and how this tension influences their functionality. It is known that memory, learning and locomotion in animals are mediated by neurotransmitters that are released from vesicles clustered at the synapse (junction between two neurons, or between a neuron and muscle). Recent experiments on the embryonic Drosophila (fruit fly) nervous system show that vesicle clustering at the neuromuscular synapse requires mechanical tension within the axons. Vesicle clustering vanishes upon severing the axon from the cell body, but is restored simply by applying mechanical tension on the severed axon. Using micro mechanical force sensors, it has been shown that embryonic axons that form neuromuscular junctions maintain a rest tension of about 1 nN. These results suggest that neuromuscular synapses employ mechanical tension as a signal to modulate vesicle accumulation. In this project, the mechanism of force generation in axons, as well as the mechanism by which tension modulates vesicle clustering, transport and release will be explored using a combination of nano scale force sensors, advanced imaging and mechanics models.
Understanding the force paradigm of synaptic function may lead to new treatments for neurological diseases. The findings of this research will be disseminated to the broader audience through the web and journal publications. The instruments to be developed will be made available to others for mechanobiological studies. The knowledge gained through this project will be integrated with education through development of a new course on neuro-mechanics that incorporates neuroscience and engineering, as well as through student seminars, involvement of undergraduate students from minorities in research, and hands-on teaching modules at the local Children's Science Museum.
