Coordinated electrical activity in the olfactory bulb gates the oscillatory entrainment of entorhinal networks in neonatal mice
Fig 4
Continuous and discontinuous patterns of oscillatory activity in the neonatal LEC.
(A) Digital photomontage reconstructing the track of the DiI-labeled multisite recording electrode (red) in a Nissl-stained (green) 100 μm–thick coronal section including LEC from a P9 mouse. The gray dots show the position of the 16 recording sites. (B) LFP recording of the oscillatory activity in LEC of a P10 mouse displayed band-pass filtered in different frequency bands and accompanied by the wavelet spectrogram (white line represents time-averaged power of the trace) as well as simultaneously recorded MUA (high-pass filter > 400 Hz) and respiration. (C) Characteristic slow continuous oscillatory activity and theta bursts from the trace shown in B when displayed at higher magnification. (D) Power spectra (mean ± SEM) of LFP in LEC during nonburst activity (blue) and discontinuous bursts (red) as well as of theta bursts normalized to nonbursting activity (purple). The respiration frequency was depicted as a horizontal bar and expanded at a larger scale (top). (E) Temporal relationship between neuronal firing and network oscillations in LEC. Left, histogram showing the percentage of spikes occurring during theta burst for all clustered units. Right, box plot depicting the firing rates of LEC units during nonburst periods and theta burst periods. Gray dots and lines correspond to individual cells (Wilcoxon signed-rank test, ***p < 0.001). (F) Histograms depicting the phase locking of LEC neurons to RR (left) and theta activity (right). Only significantly locked cells were used for analysis. Data are available in S1 Data. af, amygdaloid fissure; LEC, lateral entorhinal cortex; LFP, local field potential; MUA, multiunit activity; P, postnatal day; PIR, piriform cortex; PRh, perirhinal cortex; rf, rhinal fissure; RR, respiration-related rhythm.