Fig. 4

Schematic drawings of coupled slow and fast oscillators that exhibit cross-frequency coupling (CFC). a Slow glial (red circles) and fast neuronal (black circles) oscillators are organized within the pFRG and preBötC and modulate their intrinsic rhythms [75]. The pFRG and preBötC conditionally couple, resulting in complex variability, such as quantal slowing. b The slow respiratory oscillator (black circle) orchestrates fast neuronal oscillations (blue circles) in the anterior cingulate, premotor, insular, and hippocampal cortices via CFC [151, 152]. pFRG parafacial respiratory group, preBötC pre-Bötzinger complex, ACC anterior cingulate cortex, PMC premotor cortex, INS insular cortex, HPC hippocampal cortex