JEROME LECOQ

Séminaire présenté par Jérome LECOQ

TWO-PHOTON MICROSCOPY TO THE RESCUE : FROM NEURO-VASCULAR COUPLING TO RECORDING VERY LARGE CORTICAL NETWORKS IN VIVO

Even if our brain is a relatively small organ, it still accounts for about 20% of the whole body energy need at rest. Understanding the regulation of brain metabolism is important as it affects our understanding of some very common brain diseases like stroke. Given the complexity of vascular trees, we desperately need better techniques to measure with greater precision the regulation of oxygen metabolism.
In the first half of the talk, we will introduce a powerful new methodology to image oxygen levels in vivo with micrometer resolution.

One predominant approach to understand cognition involves recording neuronal activity in behaving animals. By correlating this activity with various aspects of a well-defined behavior task, it is then possible to gain some insight on neuronal coding. Until very recently it was only possible to record the activity of few hundreds cells in a particular brain area. Given that each neuron can receive as many as 10000 inputs, there was an urgent need to develop large-scale recording techniques that could monitor the activity of several thousands of neurons over entire cortical areas. Second as activity propagates through the brain, it quickly decorrelates with sensory inputs. We therefore also needed a tool that would record a large number of neurons in two successive stages of sensory processing. In the second half of this talk, we will introduce two complementary methodologies that address these urgent needs perfectly.