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Gain controls in parallel visual pathways of the mouse (PVPITM)
Date du début: 1 déc. 2013, Date de fin: 30 nov. 2017 PROJET  TERMINÉ 

Research in neurophysiology has identified potentially canonical mechanisms and circuits that are repeated across multiple brain regions. A classic example of a canonical computation is gain control,which in sensory pathways allows neurons to adapt their dynamic range to the statistics of the local environment. Gain control has been most studied in the visual pathway, where it helps make neurons sensitive to both spatial and temporal context. Yet many parallel nerve pathways leave the eye and terminate in different brain nuclei. It is not known whether each of these pathways use different forms of gain control or whether the same mechanisms are used throughout. This project will measure the activity of populations of nerve cells in the two major target nuclei in the brain - the lateral geniculate nucleus, and the superior colliculus - of mice. In anaesthetised mice we will characterise the gain controls that are present in these different nuclei, to understand their similarities and differences. Paired recordings from these two brain areas will be used to establish how gain controls differ in neurons that get input from the same retinal sources. In additional experiments we will make recordings from these areas in awake mice, in the presence and absence of a visual task. In each case we will characterise the gain controls and functional connectivity of neurons to establish how gain controls modulate the flow of information during visual processing. Our work will therefore provide knowledge of whether gain control forms a single canonical mechanism, or if it is used flexibly to support specific computational requirements.