(A) Schematics of the electrical stimulation. The sites of the cortical stimulation and the striatal recordings are respectively marked by blue and yellow colors. (B) Representative striatal (red) and a control cortical (blue) mean LFP traces as a response to V2 electrical stimulation. Note the 3 remarkable evoked deflections in the striatal LFP (red arrows), which represent the aggregate population activity of the mono-, di-, and polysynaptically activated CPu neurons. (C) Representative peristimulus time histograms and raster plots of a monosynaptically (left panel) and a polysynaptically (right panel) entrained CPu neuron during electrical stimulation of the V2. The insets show the waveforms and autocorrelograms of each example neuron. CPu, caudate putamen; LFP, local field potential; V2, secondary visual cortex.