Alejandro Cámera (1), Mariano Belluscio, Daniel Tomsic
(1) University of Western Australia, Australia
Escape responses to danger stimuli have been studied across many groups of animals. One of these animals is the crab Neohelice granulata. On this model the MLG2 neuron has been shown to be involved in the running speed of the crab during the escape response execution. The neural response of the MLG2 to looming stimuli of various dynamics match the running speed of the crabs to those same stimuli. Via mathematical modeling a hypothesis was proposed that MLG2 performs the visuo-motor transformation that controls the animals’ escape velocity (1). However, this was achieved using a combination of behavioral experiments made with a tracking ball device and intracellular recordings obtained from immobile animals on an electrophysiology setup, i.e., the behavioral and neuronal responses were obtained from different animals. In the last few years, we began to perform extracellular recordings while the crab is running on a treadmill device to record both neural and behavioral data simultaneously. Supporting our initial hypothesis, we found that both the initial response of the MLG2 and its’ spontaneous firing rate are enough to anticipate the running speed and the time of escape of the animal. But we also show that after the stimuli stops moving the MLG2 activity is modulated by the animals running speed. This suggests that the MLG2 does not only rely on visual stimuli to control the animal’s velocity but can integrate proprioceptive information as well.
(1) Oliva & Tomsic, JEB (2016)