Related Experiment Videos
Triggering of locust jump by multimodal inhibitory interneurons
Journal of Neurophysiology
|February 1, 1980
Summary
Researchers identified two M-neurons that trigger locust jumps by inhibiting hindleg muscles. Proprioceptive feedback during muscle cocontraction lowers their activation threshold, enabling sensory stimuli to initiate powerful jumps.
Area of Science:
- Neuroscience
- Animal Behavior
- Locust Locomotion
Background:
- The locust jump is a complex motor behavior initiated by specific neural circuits.
- Understanding the trigger mechanism for this powerful escape response is crucial for deciphering insect motor control.
Purpose of the Study:
- To identify the specific interneurons responsible for triggering the locust jump.
- To elucidate the sensory pathways and neural mechanisms underlying jump initiation.
Main Methods:
- Electrophysiological recordings in locusts to identify and characterize interneurons.
- Investigation of synaptic connections between sensory inputs, identified interneurons, and motoneurons.
- Analysis of the role of proprioceptive feedback in modulating neural activity.
Main Results:
- Two novel interneurons, termed M-neurons, were identified as monosynaptic inhibitors of hindleg flexor motoneurons.
- M-neurons receive multimodal sensory input, including from descending contralateral movement detector (DCMD) interneurons.
- High spike thresholds of M-neurons necessitate proprioceptive depolarization during cocontraction to enable sensory-evoked action potentials and subsequent jumps.
Conclusions:
- M-neurons act as critical integrators of sensory information to trigger locust jumps.
- Proprioceptive feedback during cocontraction is essential for gating sensory inputs and ensuring a powerful jump.
- The locust jump mechanism, involving sensory convergence onto identified interneurons, shares similarities with other ballistic movements in animals.