Key breakthroughs and discoveries

Brain-wide sensory networks

We have investigated whole-brain neuronal responses in vivo at the cellular level to a range of sensory stimuli. This has enabled insight into the neuronal networks that enable zebrafish to process visual stimuli (Thompson et al 2016), auditory stimuli (Vanwalleghem et al. 2017, Poulsen et al. 2020), vestibular stimuli (Favre-Bulle et al. 2018) and water flow (Vanwalleghem et al. 2020).

Changes in sensory networks occurring in models of autism spectrum disorder

We have found the fmr1 model of autism spectrum disorder and fragile X syndrome exhibits differences in processing sensory information. Notably, zebrafish carrying the fmr1 mutation show differences in adaptive correlations between neuronal activity in the visual processing system during habituation, leading to slower habituation to visual stimuli (Marquez-Legoretta et al. 2019). We have also found increased transmission and reduced filtering in the auditory processing pathway in the fmr1 fish, leading to an auditory hypersensitivity phenotype which resembles that seen in humans with the fmr1 mutation (Constantin et al. 2019).

Optical trapping in vivo

Using optical trapping (focussed light to move objects), we have manipulated the otoliths (ear stones) of zebrafish in order to produce a fictive vestibular stimulus. This technique has allowed us to investigate the vestibular system of the fish while maintaining the brain motionless under the microscope objective. This has enabled us to characterise the vestibular processing network, and responses to stimulation of the right and left otoliths separately and together (Favre-Bulle et al. 2017 and 2018).

Visual pathways during escape behaviour

We uncovered the neural mechanisms underlying the escape response elicited by visual loom stimuli using several methods to give an in-depth understanding of functional connectivity in the network. We used fluorescent labelling to map neuronal projections between the thalamus and the tectum and characterised the activity of thalamic neurons with fluorescent calcium indicators. We then ablated the thalamo-tectal pathway in order to confirm its importance in generating escape responses to looms (Heap et al. 2018). We have also described the brain-wide patterns of activity that accompany habituation to visual looming stimuli, and have modelled the neural networks that perform this important form of sensory learning (Marquez-Legorreta et al, 2019)