Simultaneous fMRI and multi-channel, spectrally resolved fiber-photometry reveals the neural basis of default mode network modulation in rats

This study establishes a novel MR-compatible multi-channel fiber-photometry platform and demonstrates 1) photometry-CBV measured in PrL and Cg co-fluctuate with global DMN signal derived from CBV-fMRI, 2) significantly enhanced 0.6-0.8 Hz GCaMP power in PrL, Cg, and RSC, but not AI, between two DMN states, 3) significantly enhanced 0.25-0.45 Hz GCaMP power in PrL, Cg and RSC precedes DMN activation peak by 3-5 s, but not AI, and 4) significantly enhanced 0.6-0.8 Hz GCaMP power in AI precedes DMN deactivation valley by 11 s.