Institut de Biologie de l'École Normale Supérieure ENS . CNRS UMR8197 . Inserm U1024 Directeur : Pierre Paoletti

Cortical Dynamics and Coding Mechanisms

Our group studies neural networks dynamics underlying sensory coding, memory formation and representation of space. We address these questions using advanced optical methods that we improve continuously in terms of sensitivity, temporal resolution, depth penetration or adaptability to freely behaving animals.

We have recently studied the tactile information collected by the rodent whiskers and described how correlated deflections of several whiskers are encoded and mapped in the barrel field of the primary somato-sensory cortex (S1bf). We currently study the formation of expectancies during sensorimotor tasks in S1bf, the formation of memories during sound to reward associations in the primary auditory cortex (A1) and the dynamics of hippocampal networks during spatial exploration.

Recording optically the spiking activity of large cortical networks with cellular resolution is still a technical challenge. Key issues are the depth penetration, the temporal resolution and the sensitivity of the optical recordings. These limitations have led us to develop acousto-optic deflectors (AOD) scanning strategies for two-photon fluorescence microscopy (TPFM). We recently developed and new type of AOD-based microscope 3D AOD scanning with patterned illumination to record from hundreds of cells at a sampling rate larger than 100Hz in awake behaving mice. Finally, our group developed a new generation of fiberscope providing optical sectioning, cellular resolution and fast frame rate imaging for recording and manipulation of neuronal activity in freely behaving rodents.