Figure 4. Differential effects of striatal activation on cortex.
A–B, Average rates of cortical units (top) normalized to basal firing aligned either to the time of a tone in failure trials or of a spontaneous lever press outside of the reward period. Units with >30 spikes in the baseline periods for each event class (press or tone) were included. Trials with optogenetic with activation of iSPNs (A) or dSPNs (B) are in blue and without in gray. Shading: ±SEM. bottom, Individual units’ normalized firing rates presented as a pseudocolored plot (as in Fig 2D) and ordered by the press or tone modulation index (low to high), without (left) or with (right) optogenetic activation.
C, Average firing rates of units during the 1.5 s baseline, ±0.25 s around a press, or 0.5 s after a tone with (y-axis) and without (x-axis) iSPN (left) or dSPN (right) activation. Error bars=SEM. iSPN activation (left) decreased firing rates for Baseline (9.6±1.0 Hz off, 5.5±0.6 on, n=193, p<0.0001), Tone (11.5±1.2 off, 6.8±0.7 on, n=193, p<0.0001), and Press (16.1±1.4 off, 13.6±1.2 on, n=179 p<0.0001). dSPN activation (right) increased firing rates for Baseline (9.0±1.3 off, 12.7 ± 1.6 on, n=136, p<0.0001), but not Tone (14.8±1.8 off, 14.7±1.8 on, n=136, p>0.05), or Press (20.3±2.2 Hz off, 19.7±2.1 on, n=136, p>0.05). Wilcoxon matched pairs signed rank.
D, Ipress calculated with (IpressON) and without (IpressOFF) ChR2 stimulation of iSPNs (green) or dSPNs (purple) are strongly correlated (p<0.0001; Spearman’s rs: iSPN 0.49; dSPN 0.83).
E, Changes in the ability of an observer to identify movements based on total cortical activity were measured with ROC analysis. Resulting area-under-curve values with and without iSPN (left) and dSPN (right) activation for each recording session.
F, IpressOFF and IChR2 of cortical units are not correlated for iSPN activation (left, p>0.05; Spearman’s rs= - 0.003) but are highly correlated for dSPN activation (right, p<0.0001; Spearman’s rs= 0.710).