New insights into the production of rhythmic motor activity
Diana Martinez published part of her Ph.D. thesis work with Prof. Farzan Nadim in the high-profile journal ELife, in collaboration with postdoctoral fellow Haroon Anwar from the Nadim lab, Prof. Dirk Bucher from our Federated Deparment of Biological Sciences, and Prof. Amitabha Bose from NJIT Math.
Rhythmic motor behaviors like walking or breathing occur at different speeds. The relative timing between different elements of the underlying movements are often maintained. For example, each cycle of the movement of a limb joint may always be 50% flexion and 50% extension, no matter how fast the rhythmic behavior is. Such “phase maintenance” can be observed even in isolated nervous system preparations in the absence of sensory feedback, and therefore arises largely from the properties of neurons and synapses of the central neural circuits controlling the behavior. The work of Martinez and colleagues uses a rhythmic circuit in the crab nervous system to show how the magnitude, duration, and specific trajectory of synaptic input into a neuron helps to maintain its relative timing within the circuit activity. The results and mathematical analysis could provide a guide for the exploration of how frequency-dependent changes in synaptic dynamics determine coordination and patterns of output in many neural circuits.