Fig. 5.

Functional interactions between corticostriatal channels. (A) Drawings depicting predictions about how the PDT between a MSN and its matching LFP should change depending on the trajectory of the slow wave and whether there is cross-talk. Cross-talk should not change the PDT between a MSN and its matching LFP when the matching LFP leads (Upper), because nonmatching cortical areas would activate too late to contribute to UP state onset in the MSN. However, if a slow wave recruits nonmatching cortex first (Lower), cross-talk would contribute to impelling MSNs into the UP state, thus reducing their PDT with the matching LFP. Circles represent matching (black) and nonmatching (gray) cortical areas; black arrows represent main directions of propagation; and gray arrows, additional putative directions of propagation (cross-talk). (B) Within any group of MSNs, waves recruiting first a nonmatching cortical area reduced the PDT between MSNs and matching LFPs (∗, P < 0.001, post hoc Holm Sidak test for any comparison between matching and nonmatching, after significant one-way repeated-measure ANOVAs). (C) Predictions can also be drawn about how cross-talk would affect transitions to the DOWN state in MSNs. These transitions should be delayed when the matching LFP turns off first, because the cortex that remains active would spread influences over nonmatching striatal regions and extend the UP state. Indeed, transitions to the DOWN state were delayed in all MSNs when the matching cortex led the transition (∗, P < 0.05, statistics as above).