Meeting Abstract

P3.163  Monday, Jan. 6 15:30  Do visual cues modulate motor control strategies during landing in toads? DESLAURIERS, A*; DANOS, N; AZIZI, E; University of California Irvine; University of California Irvine; University of California Irvine adeslaur@uci.edu

Toads are well adapted to using their forelimbs for landing during bouts of continuous hopping. During the aerial phase of hopping, toads begin to actively shorten their forelimb muscles in anticipation of landing. Upon landing the forelimb muscles are actively stretched in order to dissipate mechanical energy and decelerate the body. Previous studies have examined muscle behavior during the aerial phase of jumping and have found that intensity of recruitment increases with jump distance suggesting that toads actively modulate the length and activation of forelimb muscles to match the anticipated impact. A potential candidate for the sensory modality that is used to modulate motor control strategies during landing is vision. In the present study, we determine how changes in visual cues may affect the timing and intensity of motor recruitment in the forelimb muscles. We change visual cues in the landing arena through video playback of black and white lines moving upward or downward at a constant speed. These visual perturbations were used to alter the animal’s sense of acceleration or deceleration prior to landing. High-speed video of locomotion and electromyography in the anconeus, deltoid, and pectoralis muscles of Bufo marinus were simultaneously recorded to characterize the intensity and onset of activation. We predicted that if vision is the sensory modality used to modulate motor patterns the timing and activation of forelimb muscles will be altered based on perceived accelerations. This work will elucidate the role of vision in the predictive motor strategies used during landing in toads. Supported by NSF grant 1051691.