Skip to main content
. 2017 Jan 18;93(2):308–314. doi: 10.1016/j.neuron.2016.12.018

Figure 3.

Figure 3

IPSCs, but Not EPSCs, Are Phase-Coupled to Ripple Oscillations

(A) Representative EPSCs at −70 mV (left) and IPSCs at +10 mV (right) associated with SWRs. Upper trace indicates first derivative of EPSC/IPSC traces; green horizontal lines represent 25% (continuous) and 10% (dashed) highest minima (left) or maxima (right) in the derivative trace. Gray vertical dashed lines indicate events detected using the maximal of the derivative trace. For details, see Experimental Procedures.

(B) Overlay of 372 detected EPSCs (left) and 278 detected IPSCs (right) during SWRs in a representative cell.

(C) Polar plot of mean phase of EPSC (left) and IPSC onset (right), as revealed by peak derivative detection. Concentric rings indicate results for different percentages of largest derivative peaks (1%, 5%, 10%, 15%, 20%, and 25%). Colored thin lines represent data from individual cells, red and blue symbols and lines indicate mean, and error bars plotted on top of concentric rings represent angular deviation. Left, analysis for EPSCs (red); right, similar data for IPSCs (blue). Data are from 17 cells. Inset on top illustrates phase angle conventions. Note that the angular deviations are much smaller for IPSCs than for EPSCs, consistent with differential phase locking. p values indicate results from Rayleigh test for 10% largest derivative peaks.

(D) EPSC/IPSC-triggered averaging of LFP traces. Left, analysis for EPSCs; center, similar analysis for IPSCs, for 10% largest derivative peaks in both cases. Top, wide band average LFPs (0.5–400 Hz). Bottom, band pass-filtered average LFPs (100–250 Hz). Black thin lines represent data from individual cells; colored lines indicate average (red, EPSC-triggered average; blue, IPSC-triggered average). Dashed vertical lines indicate EPSC and IPSC onset points, respectively. Right, summary bar graphs of maximal peak-to-trough amplitude of EPSC/IPSC-triggered average (red, EPSC; blue, IPSC; upper panels, wide band average LFPs [0.5–400 Hz]; bottom panels, band pass-filtered average LFPs [100–250 Hz]). Note that the band pass-filtered signal showed marked periodicity for IPSCs, but not for EPSCs.