![]() ![]() A model that assumes two separate subpools of RRP vesicles with different intrinsic Ca 2 sensitivities predicted the observed Ca 2 dependencies of fast and slow transmitter release but could not fully account for submaximal release. During trains of action potential-like presynaptic depolarizations, submaximal release was also observed as an increase in the cumulative fast release at enhanced release probabilities. Surprisingly, the number of vesicles released in the fast component increased with Ca 2 -uncaging stimuli of larger amplitudes, a finding that was most obvious below ∼10 μ m i and that we call “submaximal release” of fast-releasable vesicles. Ca 2 uncaging, which produced spatially homogeneous elevations of i, evoked a fast and a slow component of release over a wide range of i, showing that mechanism(s) intrinsic to the vesicle fusion machinery cause fast and slow transmitter release. ![]() To test whether differences in the intrinsic Ca 2 sensitivity of vesicle fusion might cause heterogeneity of p, we made presynaptic Ca 2 -uncaging measurements at the calyx of Held and analyzed the time course of transmitter release by EPSC deconvolution. We should probably add a note to the Sleep operation that makes it clear that the operation is not intended to be accurate for very small sleep durations.Heterogeneity of release probability p between vesicles in the readily releasable pool (RRP) is expected to strongly influence the kinetics of depression at synapses, but the underlying mechanism(s) are not well understood. You might have interpreted this as Igor 6.37 being more accurate since 7.4 ms is closer to the 10 ms you specified to the Sleep operation, but that's just an artifact of the particular sleep duration you selected. On my Windows machine, the actual duration of the call to the Sleep operation is smaller and more reliable using Igor 7.06 (4.4 ms average, 0.5 ms standard deviation, n=1000) versus Igor 6.37 (7.4 ms average, 4.0 ms standard deviation, n=1000). So you're actually measuring the overhead of the sleep operation itself. So your f2() function, which specifies a sleep time of 0.01 seconds, executes with a sleep duration of 0 ticks (effectively (int)(0.01*60)). This conversion is done using regular C/C casting, not by rounding. ![]() If ( stopmstimer (- 2 )-t0- 10000 > 0 ) //interval = 0.01 sĭdd1 = threadreturnvalue (tgID,index )ĭisplay As I mentioned above, the Sleep operation converts your time specification into an integer number of ticks. Variable i, numruns = 100, reftime, interval = 0.1ĭatasleep = (datasleep - reftime ) / 1e6 - p * interval printf "i: %d, DateTime: %g, ticks: %g, mstimer: %g\r", i, data, data, dataĭata = data - reltimedatetimeĭata = data / 60 - reltimeticks / 60ĭata = data /1e6 - reltimemstimer /1e6 Variable reltimeDateTime, reltimemstimer, reltimeticks Wide-Angle Neutron Spin Echo Spectroscopy. ![]()
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