Figure 5:

Relationship between population activity in motor thalamus and motor cortex. a, Experimental setup. Spiking activity was simultaneously recorded in motor cortex with a four-shank, 64-channel probe and in thalamus with a 384-channel Neuropixels probe (n = 3 animals, n = 3 sessions). The thalamic region projecting to motor cortex was identified by optogenetic stimulation of thalamocortical terminals. b, Population trajectories for thalamus (left, green) and cortex (right, magenta) obtained with trial-averaged PCA. c, Single-trial population activity in thalamus (top) and cortex (middle), along with hand position (bottom). d, Goodness-of-fit of regression models (coefficient of determination, R²). The dependent variable was the derivative of the cortical population state for the first three principal components. The independent variable was either the cortical state (magenta), the thalamic state (green), or both (gray) for the first 1 … N principal components, where N was varied between 1 and 10. The top row shows the goodness-of-fit for trial-averaged data, and the bottom for single-trial data.