Coordinated electrical activity in the olfactory bulb gates the oscillatory entrainment of entorhinal networks in neonatal mice
Fig 5
Frequency-dependent functional coupling between neonatal OB and LEC.
(A) Characteristic traces of band-pass-filtered LFP recorded simultaneously in OB (top) and LEC (bottom) of a P9 mouse, displayed together with wavelet spectrograms showing the frequency (“Freq.”) content. Note the temporal correlation between discontinuous theta bursts in both areas. (B) Box plots displaying RR power (top, green) and theta burst power (bottom, purple) in OB and LEC. Gray lines and dots correspond to individual pups. (*p < 0.05, Wilcoxon signed-rank test). (C) Plot of imaginary part of coherence between OB and LEC showing prominent peaks in RR and theta band. The gray line corresponds to the significance threshold as assessed by Monte Carlo simulation. (D) Histograms of phase differences between RR (left, green) and theta (right, purple) activity recorded simultaneously in OB and LEC. (E) Left, bar diagram displaying the percentage of OB units coupled to the RR (green) and theta bursts (purple) in LEC and the percentage of LEC units coupled to the RR (green) and theta bursts (purple) in OB. Right, box plot showing the coupling strength of OB cells significantly locked to LEC oscillations (green: RR, purple: theta bursts) and of LEC cells significantly locked to OB oscillations (green: RR, purple: theta bursts). Gray dots correspond to individual cells (χ2 test of proportions, ***p < 0.001). (F) Histograms showing the distribution of preferred phases of LEC cells significantly locked to RR (left) and OB theta bursts (right) in neonatal OB. For comparison, histograms of OB cells locked to the respective OB rhythm are plotted as white bars. (G) Histograms showing the distribution of preferred phases of OB cells significantly locked to RR (left) and theta bursts (right) in neonatal LEC. For comparison, histograms of LEC cells locked to the respective LEC rhythm are plotted as white bars. Data are available in S1 Data. LEC, lateral entorhinal cortex; LFP, local field potential; MC, mitral cell; OB, olfactory bulb; P, postnatal day; RR, respiration-related rhythm.