Panel A: This panel displays a line graph. The x-axis represents time in milliseconds, and the y-axis represents current in picoamperes. The graph shows the response to a paired-pulse protocol with an initial 200 millisecond application of glutamate at 10 millimolar and minus 60 millivolts, followed by a second glutamate pulse after increasing interpulse intervals ranging from 5 to 800 milliseconds. The red dashed line indicates the fit of the data. Upper traces show the piezo command voltage. Panel B: This panel shows a similar line graph for Hof-98007595/98019615 heteromeric AMPARs co-expressed with Hof-TARP-98036255. The interpulse intervals increase in 5 millisecond increments, and averaged currents are overlaid in gray. The red dashed line again indicates the fit of the data. Panel C: This panel presents a scatter plot with a fitted line showing the fractional recovery of the AMPARs. The x-axis represents the interpulse interval in milliseconds, and the y-axis represents the fractional peak recovery. Two datasets are shown: black circles for Rat GluA2 with a recovery time constant of 25.4 plus or minus 3.8 milliseconds, with n equal to 3, and blue circles for Hof-98007595/98019615 plus TARP-Hof-98036255 with a recovery time constant of 54.4 plus or minus 6.6 milliseconds, with n equal to 3.
Rapid recovery from desensitization in diverse AMPARs. (A) Representative outside-out patch-clamp recording from HEK293 cells expressing Rat-GluA2 (flip, Q) AMPARs. Recovery from desensitization was measured using a paired-pulse protocol consisting of an initial 200 ms application of glutamate (10 mM−60 mV), followed by a second glutamate pulse delivered after increasing interpulse intervals (intervals from 5 to 800 ms). The fit is in red. Upper traces show the piezo command voltage. (B) Same as in A, but for Hof-98007595/98019615 heteromeric AMPARs co-expressed with Hof-TARP-98036255, interpulse intervals increasing in 5 ms increments, and averaged currents overlaid in gray. (C) Fractional recovery plot (mean ± SD, n = 3), fit with a Hodgkin–Huxley-type function, giving indicated time constants for recovery (τrecov).