Roles of the choroid plexus in brain physiology.
The cerebrospinal fluid (CSF), which fills the cavities surrounding the central nervous system and is produced by the choroid plexus, provides nutrients and chemical homeostasis to the brain. Defective production, removal or transport of CSF across the brain cavities are associated to various brain disorders, including hydrocephalus and psychiatric disorders such as anxiety and depression. The impacts of the CSF circulating and producing systems in brain functions and their mechanisms remain poorly understood.
The purpose of this application is to study the fate and functions of CSF neuromodulators produced by the choroid plexus by generating new mutant and transgenic lines, performing imaging and behavioural analyses. We aim to identify how the CSF neuromodulators from the choroid plexus are distributed in the brain and affect brain activity and behaviours in order to ultimately understand its functions in brain physiology and disease. We will use zebrafish since anatomical locations of the choroid plexus and transparency allow us to monitor and manipulate the choroid plexus and neural activity non invasively. We will use juvenile and adult zebrafish, because their brain and choroid plexus undergo further expansion and maturation, and the animals display more complex behaviours that depend on neuromodulation. Within this application
1. We will trace the neuromodulators in transgenic lines that label endogenous proteins synthesized in the choroid plexus. We will incubate animals with methionine analogues for labelling of proteins and perform biochemical experiments on dissected tissues.
2. We will ablate or overexpress neuromodulators by the choroid plexus upon genetic manipulation. Based on the literature and our current work, we identified at least three genes (e.g. npy, penka and penkb) that we will mutate and overexpress. We may generate additional mutants over the course of this project. Prior studies suggest that homozygous mutant animals are viable and show minor behavioural abnormalities (e.g. slightly increased anxiety and decreased sleep) without developmental harmful phenotypes. We plan to raise around 350 animals/line until the genetically altered line is characterized at the F4 generation.
3. We will ablate the choroid plexus epithelial cells using chemogenetics (nitroreductase-based induction of cell death upon exposure of a drug) and analyse its impact on brain barriers
4. We will perform behavioural analyses and imaging experiments of brain activity. These experiments are non-invasive in zebrafish, does not involve chronic pain or invasive surgery. The health of the animals is of great importance for all these behavioural experiments.
Using zebrafish, we replace mammalian animal models. All our experiments consider studying the function of the vertebrate brain in health and disease, hence these experiments require working with living animals. We will perform experiments in fish with various genetic backgrounds, including transgenic and mutant animals with impaired choroid plexus function. To obtain sufficient power for statistical analysis, we will perform these experiments in a total of 5870 animals including juvenile and adult developmental stages and genetic background.
We anticipate that our results will go beyond zebrafish brain and inspire novel knowledge about the function of neuromodulators from the choroid plexus in the brain of mammals.
The purpose of this application is to study the fate and functions of CSF neuromodulators produced by the choroid plexus by generating new mutant and transgenic lines, performing imaging and behavioural analyses. We aim to identify how the CSF neuromodulators from the choroid plexus are distributed in the brain and affect brain activity and behaviours in order to ultimately understand its functions in brain physiology and disease. We will use zebrafish since anatomical locations of the choroid plexus and transparency allow us to monitor and manipulate the choroid plexus and neural activity non invasively. We will use juvenile and adult zebrafish, because their brain and choroid plexus undergo further expansion and maturation, and the animals display more complex behaviours that depend on neuromodulation. Within this application
1. We will trace the neuromodulators in transgenic lines that label endogenous proteins synthesized in the choroid plexus. We will incubate animals with methionine analogues for labelling of proteins and perform biochemical experiments on dissected tissues.
2. We will ablate or overexpress neuromodulators by the choroid plexus upon genetic manipulation. Based on the literature and our current work, we identified at least three genes (e.g. npy, penka and penkb) that we will mutate and overexpress. We may generate additional mutants over the course of this project. Prior studies suggest that homozygous mutant animals are viable and show minor behavioural abnormalities (e.g. slightly increased anxiety and decreased sleep) without developmental harmful phenotypes. We plan to raise around 350 animals/line until the genetically altered line is characterized at the F4 generation.
3. We will ablate the choroid plexus epithelial cells using chemogenetics (nitroreductase-based induction of cell death upon exposure of a drug) and analyse its impact on brain barriers
4. We will perform behavioural analyses and imaging experiments of brain activity. These experiments are non-invasive in zebrafish, does not involve chronic pain or invasive surgery. The health of the animals is of great importance for all these behavioural experiments.
Using zebrafish, we replace mammalian animal models. All our experiments consider studying the function of the vertebrate brain in health and disease, hence these experiments require working with living animals. We will perform experiments in fish with various genetic backgrounds, including transgenic and mutant animals with impaired choroid plexus function. To obtain sufficient power for statistical analysis, we will perform these experiments in a total of 5870 animals including juvenile and adult developmental stages and genetic background.
We anticipate that our results will go beyond zebrafish brain and inspire novel knowledge about the function of neuromodulators from the choroid plexus in the brain of mammals.