D-121 | Visual responses of central neurons that encode stimulus acceleration are modulated by locomotor activity in an arthropod.

Sensory and Motor Systems
Author: Matias Gültig | Email: magultig@gmail.com

Matías Gültig^1°2°, Alejandro Cámera^1°2°, Damian E. Oliva^2°3°,  Daniel Tomsic1^1°2°

^1° University of Buenos aires (UBA)
^2° Institute of Fisiology, molecular biology and neurocience (IFIBYNE)
^3° Qulmes University (UNQUI)

The neural control of behavioral responses to visually detected approaching objects (looming stimuli) is increasingly studied in several animal models. However, in almost all these models the behavior entails a ballistic response, i.e. a response that once released is not further regulated. In contrast, the velocity (and direction) of the escape run of the crab Nehohelice is continually adjusted according to changes in the visual information provided by the stimulus. To further characterize this visuo-motor transformation we recorded the locomotor responses of the animal in a treadmill, simultaneously with the neuronal responses of lobula neurons using multielectrode extracellular recordings. By analyzing the responses to a variety of visual motion stimuli our results clearly reveal a strong locomotor-dependent modulation of the neuronal responses. Furthermore, responses to approaching and receding objects show that lobula neurons may encode stimulus acceleration, a property that to our knowledge has not yet been described in any neuron.