Table 3.
Electrophysiological properties of Sim1-Puro selected cells
| Parameter | 1p +2–5 | 1p +6–13 |
|---|---|---|
| Capacitance (pF) | 18.3 ± 1.3 (51) | 24.2 ± 0.9 (68)a |
| Input Resistance (GOhm) | 1.64 ± 0.49 (51) | 0.96 ± 0.17 (68)a |
| V rest (mV) | −28.5 ± 2.1 (43) | −43.7 ± 1.2 (64)a |
| % V rest less than −50 mV | 5 % | 28 %a |
| Rheobase (pA) | 10.6 ± 2.3 (14) | 18.3 ± 2.7 (34) |
| 1st spike latency (msec) | 214 ± 43 (14) | 153 ± 19 (24) |
| 1st spike amplitude (mV) | 84 ± 4.5 (14) | 95 ± 3.5 (24) |
| absolute amplitude (mV) | 23 ± 4.1 (14) | 34 ± 3.5 (24) |
| 1st spike threshold (mv) | −32.4 ± 0.8 (14) | −35.1 ± 1.0 (24) |
| 1st spike width (msec) | 4.4 ± 0.5 (14) | 2.9 ± 0.3 (24)a |
| 10 Hz 1st latency (msec) | 44 ± 3.2 (14) | 37 ± 2.0 (24) |
| 10 Hz 1st frequency (Hz) | 11 ± 0.3 (14) | 12 ± 0.3 (24)a |
| 10 Hz frequency adaptation | 1.2 ± 0.04 (14) | 1.3 ± 0.05 (24) |
| 10 Hz after potential (mv) | 0.9 ± 0.5 (14) | −0.9 ± 0.7 (24) |
| f-I slope 1st interval | 0.59 ± 0.07 (14) | 0.44 ± 0.03 (24) |
| f-I slope average frequency | 0.54 ± 0.07 (14) | 0.36 ± 0.03 (24) |
| Sag at −90 mV (mV) | 3.3 ± 1.1 (14) | 3.3 ± 0.7 (24) |
| Peak I Na (nA) | −1.06 ± 0.12 (40) | −2.09 ± 0.16 (58)a |
| Vm for peak I Na (mV) | −21.0 ± 1.6 (40) | −26.1 ± 1.4 (58)a |
Values presented as mean ± SEM (number of cells). aDenotes significantly different from 1p +2–5 days by t-test, Mann–Whitney rank sum test, or Z-test. Cell capacitance and input resistance were determined from 10 mV voltage clamp steps from a holding potential of −80 mV. First spike latency, amplitude, absolute amplitude, threshold and half-width were determined for the first spike recorded at threshold depolarization. In addition, 800 msec depolarizations that elicited spiking with an average frequency of 10 Hz were used to measure 1st latency, instantaneous frequency from the first inter-spike interval (ISI), frequency adaptation (ratio of last to first ISI), after potential as well as the initial slope of frequency versus current (f-I) plots of instantaneous and average frequency. Sag in voltage responses was determined for 800 msec hyperpolarizing current injections from −60 mV