The neural network dynamics underlying the Motion After-effect in zebrafish larva

VERONICA PEREZ SCHUSTER; MORGANE NOUVIAN; SEBASTIAN A. ROMANO; THOMAS PIETRI; GERMAN SUMBRE

Londres

Simposio; European Symposium on Imaging Structure and Function in the  Zebrafish Brain; 2012

MRC Centre for Developmental Neurobiology, King?s College London

An illusion is a perceptual misinterpretation of a real external sensory experience that may induce sensory perception in complete absence of any environmental stimulation. To better understand what are the neural network mechanisms underlying sensory illusions we are using the motion after-effect (MAE), in which exposure to coherent continuous motion for a certain period of time induces motion perception in the opposite direction following the end of the moving stimulus. Even thought this effect has been intensely study at the behavioral and single-cell physiology levels using different experimental models, the neural network representation at different sensory processing brain regions remains elusive. For this purpose we are using the zebrafish larva as the experimental model, which allows monitoring the dynamics of large neural networks from large portion of the nervous system in a behaving organism. After behaviorally validating the existence of a robust motion after-effect visual illusion when presenting to zebrafish larvae coherent continuous moving visual stimuli, we performed similar experiments in intact transgenic larvae expressing a genetically encoded calcium indicator (GCaMP3) under a two-photon scanning microscope. Preliminary results show neurons, within the larval optic tectum (the largest and highest visual center of teleost fish), that stand as a neuronal correlate of the behavioral illusory response implying that this ensemble of neurons may be involved in the perception of the MAE visual illusion.