Fig. 6: Electrophysiological recording in the piriform cortex of a mouse brain slice.

a Photograph of a 35 μm-thick silk parylene probe inserted into a mouse brain slice: insertion occurs with no sign of buckling. b Scheme of the placement of the silk-parylene neural probe. c Traces show two consecutive epileptic seizures. The upper trace corresponds to the bandpass filtered signal (300–3000 Hz) used to reveal spiking activity, and the bottom trace corresponds to the low pass filtered signal (cutoff at 100 Hz) used to reveal slow changes in the LFP. d Traces show spontaneous spiking activity occurring between epileptic seizures. The dashed line indicates the threshold used for sorting action potentials. It is set at −4xRMS of the voltage trace (RMS calculated outside of the epileptic seizure). The action potentials that cross the threshold are examined through cluster analysis and interspike interval analysis. e Overlap of the action potentials recorded over 5 min at high temporal resolution. The constancy of the spike shape and refractory period (6.4 ms in that case) definitively ensures that the blue action potentials belong to one single unit. The action potentials in black correspond to multiunit activity