FP6Individual fellowship2005–2007

KEBUSCH · The role of neuronal compartmentalization in generating specific behavioural responses in C. elegans

FP6 — Marie Curie Actions (Human Resources and Mobility)

Duration
2005-12-01 → 2007-11-30
EU contribution
€159,046
Participants
1
Scheme
EIF

Lines connect the coordinator with its partners.

Results in brief

Final Activity Report Summary - KEBUSCH (The role of neuronal compartmentalisation in generating specific behavioural responses in C. elegans)

A major determinant of an organism's survival is its ability to forage, to locate and harvest food. Our lab showed previously that sensing the concentration of ambient oxygen plays a key role in regulating feeding. In the context of this behavioural paradigm, I aimed, in my project, to create a detailed understanding of the behavioural strategies involved, and to unravel the functioning of the neural circuit underlying it, how neural computation carried out in specific neurons generates the behaviour. For this I developed novel behavioural assays, as well as the image analysis and quantification tools to investigate worm locomotion on food. My observations from these assays suggest that the biased random walk model thought to govern C. elegans chemotaxis responses is insufficient to fully explain their locomotory patterns. Controlled swings of the head regulated by sensory cues appear to contribute substantially to worm navigation. Part of the neural circuit of head neurons that controls these head swings has tentatively been identified through the use of ablations and genetic mutants. A central aspect of analysing the functioning of the nervous system is to record their electrical activity. For this, it is highly desirable to target proteins that monitor neural activity to specific neurons, and within these neurons, to their synapses. Using the Multisite Gateway cloning system, I created a library of different genes and promoters that can be freely combined to create fusion proteins. This library was used to target genetically encoded calcium sensors to the synapses of a specified subset of neurons. I also established the use of a light-gated cation channel, Channelrhodopsin, which allows to directly manipulating the electrical activity of individual neurons involved in behavioural responses to oxygen.

Data: CORDIS, © European Union

Project objective

A fundamental question in neurobiology is how specific behaviours are controlled at the level of molecules, cells, and neuralcircuits. In this proposal I aim to investigate how different synapses within the same neuron are specialized, how thisspecializati on contributes to, information processing in the neuron and, ultimately, to specific behavioural responses. Toinvestigate this problem I will study feeding behaviour in the nematode C. elegans. Different wild strains of C. elegans exhibitdifferent feeding strategies, which can be causally linked to the specific action of receptors, sensory neurons, andinterneurons. I will combine genome-wide RNAi screening with forward genetic approaches to identify new molecules thatcontrol how C. elegans respond to food. The function of these genes will be tested using 1. Behavioural assays, 2. Newlydeveloped labels for different post-synaptic elements in the same interneuron, and 3. Genetically encoded indicators of neuralactivity. Ultimately, I hope to understand how inf ormation received at distinct post-synaptic elements from different pre-synaptic partners sculpts neuronal output and behavioural response.

Original text from CORDIS.

Participants

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Data: CORDIS, © European Union