Extended Data Fig. 2: Comparison of SWR statistics across preparations and recording conditions.
From: A claustrum in reptiles and its role in slow-wave sleep
a, Slice preparation (see Methods) for field-potential recordings. b, Spontaneous sharp waves (LFP; <150 Hz) and corresponding ripples (high-pass (HP) band; 70–150 Hz) in the amDVR. Insets: top left, magnification of the SWR marked with a dotted box; top right, 350 ripples; high-pass signal intensity (HPI) >70 Hz aligned on trough of sharp wave (overlaid as average). c, Distribution of amplitude (x) and width (y, full width at half maximum) of SWR events in a representative DVR slice. d, Distribution of SWR amplitude and width (as in c) in a representative ex vivo preparation. e, Ratio of amplitude (μV) to width (ms); n = 5 sleep epochs from 3 animals (in vivo; blue), 4 ex vivo brains (red) and 12 slices (green). Lines show the mean. f, Autocorrelation function of sharp-wave times, showing that the characteristic rhythmic modulation of sharp-wave generation (which is due to the alternation of slow-wave sleep and REM sleep with a 2–3 min period) in sleeping animals is absent from both ex vivo brain preparations and slice preparations (n = 5 sleep epochs from 3 animals (in vivo), 4 ex vivo brains and 12 slices). g, Whole-cell patch-clamp recording (in current-clamp mode) of a DVR neuron (Vm), together with LFP recording in a neighbouring region (V (LFP)) with a glass micropipette. Note the simultaneous depolarization of the neuron and SWRs, and moderate neuronal depolarization that gives rise to occasional firing (three action potentials here). The experiment was repeated with 12 neurons. h, Whole-cell patch-clamp recording of an amDVR neuron in voltage-clamp mode, held at depolarized (blue) and hyperpolarized (red) holding potentials (Vh). Note the volleys of excitatory (red) and inhibitory (blue) currents at each SWR (LFP), and the near absence of synaptic input in between. i, Spike times of a patched amDVR neuron in relation to sharp waves. Note the locking to the sharp-wave trough (t = 0), and the absence of firing otherwise (n = 2 amDVR neurons). j, Mean excitatory (ge) and inhibitory (gi) conductances (n = 20 and 21 events, respectively). The black and grey lines show averaged sharp waves recorded with inhibitory and excitatory conductances, respectively. Traces are aligned on the sharp-wave trough.
