The interpolated trace was binned into 5 ms bins, and we looked for the first time the binned trace decreased monotonically for ≥ 20 ms and ended within 5 mV of the “starting AP”’s threshold. If no such drop existed, we looked for the longest existing monotonic drop ending within 5 mV of the “starting AP”’s threshold. We considered the time of the minimum Vm within the last bin of the monotonic drop to be “tentative end time (d),” where the last bin was allowed to extend past the original 20 ms decrease or the end of the horizontal line in order to capture the entire slow decay. (In a small number Selleck AZD9291 of special cases, there were

no decreases between successive bins, so the “tentative end time (d)” was taken from within the last bin.) The idea was that suprathreshold events generally end with a smooth decay of ≥ 20 ms that returns close to the “starting AP”’s threshold, with shorter decays allowed for shorter events (e.g., single APs versus CSs) where repolarization may not be strong enough to overwhelm subsequent input for a full ∼20 ms. We then set the event’s end time to be the earliest of the tentative end times (b–d). If it was (b) or (c), the end time was revised by setting it to the

time of the minimum Vm in the last 5 ms bin between the two successive APs that had dropped from the previous bin. We then moved on to the first AP after the end time; this became the new “starting AP.” When the last AP was reached, the Vm between the start and end time

of each event was removed and the trace linearly interpolated across the gaps to yield the subthreshold Vm trace. Dasatinib research buy The mean of the subthreshold trace as a function of the animal’s location for a given head direction was binned in the same way as the AP firing rate in the “Place Field Classification” section to give the subthreshold field. Finally, we note the effect of the small hyperpolarizing holding current applied to some of the cells during awake recording. This would tend to hyperpolarize the Vm by ∼RN × the holding current. To check that the results ( Figures 4B–4G) were probably not affected by this, we estimated what the subthreshold values would have been if no holding current was applied but kept the AP thresholds the same to make a conservative comparison (though one would actually expect thresholds to rise along with Vm based on Figure S1D and thus keep all the results “in register”). the The results were unchanged: baseline Vm (place: −65.1 ± 2.2 mV versus silent: −58.2 ± 2.3 mV; p = 0.056), peak subthreshold Vm (−52.3 ± 2.4 versus −55.2 ± 2.2 mV; p = 0.38), threshold – baseline (9.3 ± 1.3 versus 10.9 ± 1.2 mV; p = 0.38), peak – baseline (12.8 ± 2.8 versus 2.9 ± 0.3 mV; p = 0.024, unchanged because both values were corrected by the same amount), peak – threshold (3.5 ± 1.7 versus −7.9 ± 1.1 mV; p = 0.00072). To classify an event as a CS, we started with the interpolated trace for a given event (in which the fast events, i.e.