Research

The Barral lab studies how neuronal information is propagated along the auditory pathway.

Processing of auditory information in the brain is complex because information not only flows from the auditory periphery to the central nervous system but also from the brain to the ear. As a result, efferent neuronal signals can modulate the mechanical properties of the cochlea. While this continuous and bidirectional interaction between the cochlea and the brain is central in shaping hearing properties, it remains poorly understood. Ideally, we would like to know the cochlear output precisely to study its effect on neural representations. However, because cochlear mechanics and neuronal processing are reciprocally coupled through mechanoelectrical feedback, it will require specific tools to uncouple them and to decode the transformation of complex acoustic stimuli by the brain.

Research goals

The aim of our research is to study how information is propagated and processed from the auditory periphery to the cortex. To control the cochlear output and extract the feedforward component of the auditory pathway, we intend to develop an optogenetic approach to activate cochlear hair cells in vivo and use this technique to resolve long-lasting questions about the nature of the neural code in the auditory system. Having a full control of the output that the cochlea delivers, we will be able to manipulate it systematically in order to ask and answer new questions: How does the cochlea process the sound input? What type of information is propagated along the auditory pathway? What is the underlying neuronal circuit?

Our approach

Our research combines in vivo characterization of auditory processing, in vitro description of the underlying pathway, and in silico analysis to understand the neuronal circuit that enables the transformation of sounds by the auditory system. Potential outcomes can resolve long-lasting questions about the nature of the neural code in the auditory system and allow building accurate models to open a new line of research in the field of sensory neurosciences.