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. 2016 Dec 15;6:39226. doi: 10.1038/srep39226

Figure 7. Relationship between stimulus envelope, spiking, and slow and fast LFPs (sLFPs and fLFPs, respectively).

Figure 7

(a) Shows LFP and spike data recorded during one trial of the long distress sequence. The data corresponds to the same neuron represented in Fig. 6a–f. (a) Shows (from top to bottom): the envelope of the long distress sequence; the spike trace obtained in one trial of this sequence; the concomitantly recorded slow LFP (i.e. 2–15 Hz); the instantaneous energy of the sLFP (calculated based on the Hilbert transform, see Methods); the fast LFP (i.e. 76–124 Hz); and the instantaneous amplitude of the fLFP. (b–c) Population data calculated from all trials tested in all recording sites of each cortical hemisphere (n = 2220 (left), n = 2530 (right)). (b–c) Show (from top to bottom): the envelope of the long distress sequence, the median post-stimulus time histograms (PSTH); the median sLFPs, the median instantaneous energy of the sLFPs, the median fLFPs; and the median instantaneous energy of the fLFPs. For calculating median population data, signals (i.e. PSTHs, LFPs, instantaneous energies) were normalized to their absolute maximum value. Grey lines indicate 25th and 75th percentiles. Note that the instantaneous energy of the sLFP decreased as the sequence evolved, similar to what happened to the spiking activity (see median PSTHs). On the other hand, the instantaneous energy of fLFPs followed the energy content of the sequence’s envelope. (d) Comparison of maximum cross-correlation coefficients calculated between the stimulus envelope, and the PSTHs and median instantaneous energy of sLFPs and fLFPs obtained in each recording site of each cortical hemisphere. Median sLFPs and fLFPs were obtained from all trials of the long distress sequence tested in each studied recording site. In the box-plots, central marks are median values, boxes indicate 25th and 75th percentiles, and the whiskers extend to the most extreme data points not considered outliers. The results of a parametric ANOVA are given, as well as the results of a Tukey post hoc test (***p < 0.001, Kolmogorov test for normality, p > 0.15 for all groups). Note that only the instantaneous energy of fLFPs correlated well with the envelope of the long distress sequence.