Firingpatternsoftheaboveshowncells.Noticethepresenceofasaginthehyperpolarizingresponse. ... Notice the similarity with the firing patterns shown in A.
Figure 7A and 7D legends
On the -100 pA step all three cells show a sag under both readings of the criterion, with V_min from a 1 ms running mean. Reading (a), relaxation from the peak hyperpolarization to the mean of the step's last 100 ms, gives 17.5, 7.9 and 8.7 mV (1May2012_P3, 20Sept2011_P2, 24October2012_C2), 22 to 47 times the threshold of twice the pre-step SD (0.19 to 0.56 mV). Reading (b), the sag ratio, gives 0.448, 0.224 and 0.208, above 0.1. Both give 3 of 3 cells. Across all variants (raw or 1 ms running-mean V_min, end windows of 50 to 200 ms) the smallest sag is 42.4 baseline SDs and the smallest ratio 0.200, both from the running mean with a 200 ms end window (with raw V_min, 42.7 and 0.201); the outcome holds up to a 10 SD threshold or a ratio threshold of 0.15, and at 0.2 two of three cells pass. The 2 SD threshold of reading (a) does not separate a sag from noise in these recordings. Each cell's 0 pA sweep gives 1.3 to 2.4 mV, 2.8 to 20.1 pre-step SDs, and so passes it, because the 75 ms pre-step baseline misses slow fluctuations over the 1 s step (SD 0.59 to 1.03 mV in the 0 pA step window). On a synthetic trace without sag the raw minimum passes reading (a) in 100 of 100 draws and the 1 ms running mean in none; reading (b) passes in none. Against the 0 pA sweep the -100 pA sags are 4.5 to 7.3 times larger, and 4.2 to 10.8 times twice the SD of the 0 pA step window, and the 0 pA "sag" is 0.038 to 0.061 of each cell's -100 pA hyperpolarization, below reading (b)'s 0.1, so the outcome holds on references that separate a sag from noise. Reading (b) applied to a 0 pA sweep alone passes in all three cells (0.71 to 4.94), since with no hyperpolarization the ratio divides noise by noise. The cell the old description places in Figure 7D (24October2012_C2, P15, Sst-Cre;ChR2) has a ratio of 0.208, close to the 0.224 of 20Sept2011_P2 and below the 0.448 of 1May2012_P3. The firing at +50 pA (15, 15 and 18 spikes in 1 s) is shown as a description only. The claim's firing-pattern similarity is judged by the sag, as the criterion says; whether the whole firing pattern of the 7D cell is similar is not tested. The deposited traces were not compared with the printed Figure 7 traces, since the PDF could not be rendered here; the notebook plots the first 300 ms of each -100 pA step for that comparison. The question of how the paper judged a sag is recorded as a methods_unavailable finding for the paper's authors.
How the test differed from the paper’s method
- The paper shows the sag in example traces and defines no measure; the claims file's two readings are run, both give 3 of 3, and the outcome rests on that assumed measure, as the criterion says.
- The pre-step baseline for both readings is all of each sweep before the step (0 to 75 ms); the criterion names no window, and this is a standard choice. V_min is the minimum of a 1 ms running mean during the step, a standard choice, with the raw minimum as a variant; neither changes the outcome. The raw minimum was the main measure in the first version, but it picks the most negative noise sample and passes reading (a) on a trace without sag, so the running mean replaced it after round 1 of verification.
- Reading (a)'s threshold, as the criterion states it, is passed by the 0 pA sweeps of all three cells. The comparison with the 0 pA sweep (same measure, and twice the SD of the voltage in the 0 pA step window) is shown as a reference; it is not part of the criterion and does not change the outcome.
- Which cell is in which panel of Figure 7 is taken from the superseded description in the bucket's hc-9/old/ folder (ages P13, P14 and P15 and the mouse lines, which match the Figure 7 legends); the files and the current description do not say. The criterion judges every cell alike, so the outcome does not depend on it.