The Journal of Neuroscience, October 25, 2006, ():
Impaired Inactivation Gate Stabilization Predicts Increased Persistent Current for an Epilepsy-Associated SCN1A Mutation
J. Neurosci. Kahlig et al.
26: 10958
Supplemental data
Files in this Data Supplement:
- supplemental material -
Table 1
- supplemental material
-
Figure S1. Whole-cell currents generated by previously reported SCN1A models
Simulated whole-cell currents generated by previously reported computational models for SCN1A (Barela et al., 2006; Clancy and Kass, 2004; Spampanato et al., 2004b; Spampanato et al., 2004a). The stimulation protocol was identical to that used in Fig. 3A and the red trace highlights the voltage step to –10 mV.
- supplemental material
-
Figure S2. Analysis of whole-cell currents generated by other SCN1A models
Comparison of the whole-cell current measured from heterologously expressed WT-SCN1A (black symbols) and those generated by the previously reported SCN1A computational models (colored symbols). Whole-cell currents were elicited by voltage steps to potentials between –80 and +60 mV from a holding potential of –120 mV (stimulation protocol used in Fig. 4A). (A-B) Peak current amplitude and time to peak current plotted for each potential, respectively. (C) The voltage-dependence of channel activation was plotted using the normalized conductance values. (D) Inactivation time constants were estimated by fitting the decay phase of the whole-cell currents in Fig. S1 with a single exponential function. Fitting the current decay with a double exponential equation failed to reveal a second inactivation time component. For comparison with actual SCN1A inactivation, the fast inactivation time constants are plotted for each potential (data from Fig. 4D).
- supplemental material
-
Figure S3. Fast inactivation exhibited by other SCN1A models
Comparison of fast inactivation exhibited by heterologously expressed WT-SCN1A (black symbols) and the previously reported SCN1A computational models (colored symbols). (A) Voltage-dependent entry into fast inactivation was examined using a two-pulse protocol consisting of a 100 ms conditioning pulse at various potentials followed by a test pulse at –10 mV. (B) Time-dependent recovery from fast inactivation was examined using a two-pulse protocol consisting of a 100 ms inactivation pulse at –10 mV followed by a variable length return to –120 mV and a second test pulse to –10 mV.
- supplemental material
-
Figure S4. Slow inactivation exhibited by other SCN1A models
Comparison of the slow inactivation exhibited by heterologously expressed WT-SCN1A (black symbols) and previously reported SCN1A computational models (colored symbols). (A) Time-dependent entry into slow inactivation was examined using a two-pulse protocol consisting of a variable length inactivation pulse to –10 mV followed by a test pulse at –10 mV. Effects of fast inactivation were minimized using a 50 ms inter-pulse to –120 mV to relieve fast inactivation. (B) Voltage-dependent entry into slow inactivation was examined using a two-pulse protocol consisting of a 30 sec conditioning pulse at various potentials followed by a test pulse at –10 mV. Effects of fast inactivation were minimized using a 50 ms inter-pulse to –120 mV to relieve fast inactivation. (C) Time-dependent recovery from slow inactivation was examined using a two-pulse protocol consisting of a 30 sec inactivation pulse to –10 mV followed by a variable length inter-pulse to –120 mV and a test pulse to –10 mV.
- supplemental material
-
Figure S5. Persistent current exhibited by other SCN1A models
(A) Whole-cell simulations of previously reported SCN1A models (colored lines) reveal wide variation in levels of persistent current compared to heterologously expressed WT-SCN1A (black line). Representative currents generated in response to a 200 ms voltage step to –10 mV and normalized to peak current amplitude. (B) The persistent current generated by previously reported SCN1A models varied between 0.06 and 2.28 % of peak. Persistent current measurements were made during the final 10 ms of a 200 ms voltage step.
2.gif){kind=link}
3.gif){kind=link}
4.gif){kind=link}
5.gif){kind=link}
