Neuronal circuits and sensory coding

Team - Neuronal circuits and sensory coding

Our brain is constantly undergoing important state changes such as switching between different levels of alertness or attention. At the cellular level, these variations in brain state are characterized by large fluctuations in neuronal activity. At the behavioural level, these variations affect our ability to process and interpret the sensory information that we receive. For example, a person who is falling asleep is less likely to hear and make sense of the sounds around them. Our team aims at understanding the brain circuits responsible for this phenomenon, by focusing on the effects of alertness on the coding of sensory information.

Our brain is composed of tens of billions of neurons which participate in various cognitive functions, including sensory processing. These neurons are highly diverse, and they each have a unique molecular fingerprint, called transcriptome. How do these diverse neurons support the effects of brain state on sensory perception? What is the link between genetic identity and neuronal function in the brain?

Our lab uses functional imaging techniques and in situ transcriptomics to answer these questions. We use in vivo 2-photon calcium imaging in the cerebral cortex to record neuronal responses to sensory stimuli. Simultaneously, we monitor behavioural parameters to estimate alertness. Following these recordings, we explore the transcriptome of the recorded neurons using coppaFISH, a method of in situ transcriptomics, which can read the expression of >100 genes on brain sections at single cell resolution. This pipeline allows us to relate the function of individual cortical neurons to their genetic identity by aligning the same neurons between the two modalities.