Fig. 1: Spontaneous interictal-like activity and dysmorphic neuron topography in human FCDIIb brain cortical slices.
a, Left, micrograph of a cortical slice of resected brain tissue from a patient with FCDIIb (patient ID 8, slice 3) showing MEA layout. Electrodes are color-coded to indicate the type of activity detected (red: IILDs and MUA; orange: MUA only; green/pink: no activity; gray: defective electrodes). Right, representative recording of the simultaneous activity on the electrodes located within the area delimited by the black dotted lines. Recordings from electrodes with IILDs+MUA or MUA only are outlined and color-coded as in the left panel. b, Top, representative traces of the raw signal of an IILD (left) or a spike (right) from the two boxed portions of recordings shown in d. The signal is represented after low-pass filtering (<40 Hz) to reveal the slow component of the IILD or band-pass filtering (100–500 Hz) to reveal spikes and high-frequency oscillations. Spectrograms of the raw signals (bottom) show that the IILD includes high-frequency components superimposed on a slow oscillation, whereas the spike shows only a sharp, high-frequency component. c, Mean MUA frequency recorded in slice 3 from n = 4 electrodes displaying IILDs (IILD+) and n = 4 without IILDs (IILD−). *P = 0.0286, two-tailed Mann–Whitney rank-sum test. d, Representative recordings from color-coded electrodes shown in a, with corresponding raster plots of IILDs and MUA. Recordings are shown in control ACSF and after switching to high-K+ ACSF to promote neuronal activity. Note that MUA increases in all three recorded areas, whereas IILDs remain restricted to the electrode that previously displayed them. e, Immunofluorescent stainings from slice 3 with antibodies against pS6 (red) and NeuN (green) in areas delineated by color-coded dashed lines in a. White horizontal arrows indicate DNs (NeuN+/pS6+) and yellow vertical arrows indicate BCs (NeuN−/pS6+). density (d) = number of dysmorphic neurons per mm2. Scatter dot plots are presented as mean ± s.e.m. LFP, local field potential.
