FRIPRO-Fri prosjektstøtte

Motile cilia are miniature whip-like organelles, which generate fluid flow in diverse systems across the animal kingdom. The flow generated by cilia is a subject of great interest, as motility defects of cilia result in human diseases, known as motile ciliopathies. In the brain, motile cilia move cerebrospinal fluid, which is a clear liquid containing various factors important for brain development and function. To date, it remains poorly understood how the content and the movement of cerebrospinal fluid contribute to brain physiology. In this project, we aim to understand how fluid flow is generated within the nervous system and how it regulates brain development. We will address these questions in a small genetic model organism, the zebrafish, since it allows us to monitor and manipulate ciliary beating, fluid flow and neural activity while recording the physiology of the brain. On the long term, we expect our work to shed light on widely unexplored neurological processes and bring forward novel concepts on the interaction between the brain and the cerebrospinal fluid. During this first period, we have established the framework to study the function of motile cilia in the nervous system. 1. We have well characterized how motile cilia and fluid flow change during development, and identified the cilia and brain ventricle phenotype of a series of mutants. This work is now in press in Cell Reports, with publication date of 5th October 2021. 2. We have optimized the RNA extraction and sent our first set of mutant animals for RNA sequencing. We expect that these results will guide us in identifying pathways affected in motile cilia mutant 3. We optimized a new approach to do multiplexed in situ hybridization of whole larvae, which will be crucial to validate our RNA sequence findings. 4. We have crossed all our mutant lines with reporters of neuronal activity, and have optimized the workflow to measure spontaneous and light stimuli-evoked activity. Due to COVID-19 and the strict entry restriction of Norway, the postdoc started in August 2021 instead of June 2021. Luckily, we could optimize many techniques in the meantime with other students and team members from the laboratory.

Motile cilia are miniature whip-like organelles, which generate fluid flow in diverse systems across the animal kingdom. The flow generated by cilia is a subject of great interest, as motility defects of cilia result in human diseases, known as motile ciliopathies. Despite the abundance of these cilia and the wide spectrum of clinical features in ciliopathy patients, the factors regulating ciliary beating and the function of cilia-mediated flow remain poorly understood. This is especially the case for the brain, whose ventricular surface is decorated by motile ciliated cells, known as ependymal cells, which contribute to the movement of cerebrospinal fluid (CSF). Even though these cells were discovered decades ago and are associated with pathological conditions such as hydrocephalus, how ependymal cells and CSF flow specifically modulate the nervous system remains unknown and highly speculative. In this project, we aim to understand how fluid flow contributes to brain development and function. Our main objectives are to identify how ciliary beating and CSF flow in the brain ventricular system regulate the development and physiology of the brain, and whether the nervous system modulate motile cilia and CSF flow to fit to its needs. We will address these questions using zebrafish as model system since it allows us to monitor and manipulate ciliary beating, CSF flow and neural activity while recording the physiology of the brain, using techniques that we have already developed. Altogether, we expect our work to shed light on widely unexplored neurological processes and bring forward novel concepts on the interaction between the brain and the CSF.