All-optical interrogation of neural circuits during behaviour (360G-Wellcome-204651_Z_16_Z)

Neural circuits display complex spatiotemporal patterns of activity on the millisecond timescale. Understanding how these activity patterns drive behaviour is a fundamental problem in neuroscience. To address this challenge, I have recently introduced a novel approach that combines simultaneous two-photon calcium imaging and two-photon targeted optogenetic photostimulation with the use of a spatial light modulator (SLM) to provide 'all-optical' readout and manipulation of the same neurons in vivo. I propose to probe the neural code in mouse barrel cortex during sensory-guided behavioural tasks by using this approach to uncover the underlying mechanisms of decoding and encoding of information by ensembles of neurons. I will train mice to make perceptual decisions based on quantitative control of cortical activity, as well as perturb neural activity in somatosensory cortex while animals are performing discrimination tasks using their whiskers. I can perform decisive tests of theoretical models describing the neural code by assessing the spatiotemporal pattern of activation required in somatosensory cortex to drive a behavioral response. These experiments will shed light on how many neurons with which functional signature are minimally sufficient to subserve a percept.