What resolves this contention: Optogenetic gain-of-function in Kravitz et al. s…

What resolves this contention: Optogenetic gain-of-function in Kravitz et al. supports the classical antagonism model whereas natural-activity recording in Cui et al. observes concurrent activation, suggesting that artificial bilateral pathway-isolated stimulation does not reflect normal coordinated CBGTC dynamics. / Optogenetic excitation of D1-Cre direct-pathway MSNs and D2-Cre indirect-pathway MSNs produces opposing motor phenotypes (locomotion vs parkinsonism), supporting strict pathway antagonism in motor control. / Fiber photometry recordings in D1-Cre and A2A-Cre mice show that direct- and indirect-pathway SPNs are CONCURRENTLY (not antagonistically) activated immediately before action initiation, challenging the strict opposing-pathway interpretation.