Efficient mapping of the thalamocortical monosynaptic connectivity in vivo by tangential insertions of high-density electrodes in cortex

Thalamus provides the principal input to cortex, thus understanding the mechanisms of cortical computations in behaving animals requires to characterize the thalamocortical connectivity in vivo. We show that tangential insertions of high-density electrodes into mouse cortex capture the activity of thalamocortical axons simultaneously with their synaptically connected cortical neurons. Multiple thalamic synaptic inputs to cortical neurons can be measured providing an efficient approach for mapping the thalamocortical connectivity in vivo.