Adaptive changes in neuronal receptive fields during different conditioning strategies
Dates:18 September 2017 - 29 June 2018
Date limite de candidature:29 June 2018
~ Sept-Dec 2017
~ Jan-March 2018
~ April-June 2018 (to be discussed)
We propose to study how cortical receptive fields in the primary auditory cortex (A1) can be rapidly reshaped by behavioral conditioning. We will use multi-electrodes (Silicon probes) to record neuronal activity in anaesthetized and in awake mice. We will focus on adaptive plasticity in receptive fields of A1 neurons, and explore how operant conditioning for a single tone can change the receptive field properties of both inhibitory interneurons and excitatory pyramidal cells, and how this process depends on cortical layers.
Experiments will consist in (i) implanting electrodes over the auditory cortex of naive mice, (ii) measuring neuronal receptive fields in a large ensemble of neurons, (iii) training animals on an auditory task, (iv) measuring changes in the receptive fields of the same cells following conditioning. An important aspect of these experiments is that we will use two different reinforcement strategies during training – one group of mice will receive aversive (negative reinforcement) conditioning and a second group of mice will receive appetitive (positive reinforcement) conditioning. This will allow us to analyze the effects of reward valence, as well as tone conditioning, on neuronal receptive field plasticity. In parallel, a PhD student in the team is currently studying the effect of conditioning in the upper layers of A1 (layers I-III) with two-photon microscopy calcium imaging. The comparison of the observed changes in supragranular, granular and subgranular layers of A1 will provide a complete view of the circuit rearrangements taking place in this cortex during learning. This is a collaborative project between our group and Dr. Shihab Shamma’s group at the DEC department (ENS). The supervision of this project will be done by Jean-François Léger in Laurent Bourdieu’s team at IBENS and Yves Boubenec in Shihab Shamma’s team at the DEC. These experiments will provide a better understanding of the cellular basis of adaptive neuronal changes during classical conditioning, and also yield new insights into the effects of learning and reward on early sensory processing.
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