Navigation

Navigation
Decipher circuit mechanisms controlling chemotaxis

How do animals from the start of their autonomous life optimally explore their environment to find food and favourable environmental conditions while not wasting too much energy? The generation of smart exploratory behavioral action patterns is essential to maximize survival. Zebrafish larvae are an interesting model to study this question because despite being quite simple, from the time they start exploring, they have 5 days to feed or they will die. We have developed an inference method to analyze these exploratory behavioral action patterns and found that zebrafish larvae reproduce highly stereotyped sequences. These sequences reflect the functional organisation of "conductor" motor centers controlling exploration in the brain. We now have means to investigate their structure and function by combining population imaging, genetics, optogenetics, and in vivo electrophysiology.

This project will rely on behavior analysis of zebrafish larvae exploring in neutral conditions as well as animals exposed to chemical gradients. Chemosensory integration in peripheral sensory organs modulates the activity of motor centers in the brain in order to change direction, speed and sequences of bouts during exploration. This PhD project will unravel the algorithm deployed by zebrafish larva to navigate and the underlying neuronal circuits using population imaging, genetics, optogenetics, and in vivo electrophysiology in order to build an integrated circuit model of zebrafish navigation.

Publications

  • Publication 1: Knafo S, Fidelin K, Prendergast A, Tseng PE, Parrin A, Dickey CW, Bohm UL, Nunes Figueiredo S, Thouvenin O, Pascal-Moussellard H, Wyart C# [2017]. Mechanosensory neurons control the timing of spinal microcircuit selection during locomotion. eLife 6:e25260 DOI: 10.7554/eLife.25260.

  • Publication 2: Hubbard J, Böhm U, Prendergast A, Tseng PE, Stokes C, Newman M, Wyart C# [2016]. GABAergic sensory neurons project onto key elements of the escape circuit, Current Biology 26: 2841-2853.

  • Publication 3: Severi, KE, Böhm, UL, Wyart C# [2018]. Investigation of hindbrain activity during active locomotion reveals inhibitory neurons involved in sensorimotor processing, Scientific Reports, 8:13615.