What is neurovascular transduction?
The term ‘neurovascular transduction’ is often used to describe the transduction of sympathetic nerve activity to regional vascular responses.
The transduction toolkit supports the calculation of neurovascular transduction using beat by beat measurements of muscle sympathetic activity (MSNA) and blood pressure.
|Transduction gain||Determines the slope relating MSNA burst area and the change in diastolic blood pressure as described in Briant et al., 2016.|
|R2||Coefficient of determination relating the slope between MSAN burst area and the change in diastolic blood pressure.|
|Nerve signal select||Defines the channel that corresponds to the integrate MSNA neurogram. Please ensure accurate channel labelling during Aggregate.|
|Corruption threshold||Threshold on first derivative of the raw neurogram for deciding that a R-R interval is corrupted by large instantaneous changes characteristic of transient noise spikes and muscle twitch artifacts.|
|Rise threshold||Threshold for determining what constitutes a valid burst in the neurogram. The criteria for burst identification is based on amplitudes and slopes of rise and fall of candidate bursts compared against critical values (1). The height, rise slope, and fall slope are scaled proportionally such that if 2 of the 4 criteria are met, the area surrounding the burst is set to zero, creating a beat-by-beat detected neurogram.|
|Pressure bin size||Size of bins for grouping diastolic blood pressures. Default is 3 mmHg.|
|N1, N2||MSNA burst area is most correlated
with diastolic blood pressure when it precedes it by a given lag. Bryant et al., report that the optimal gain is obtained for 8–6 cardiac cycles (i.e. N1=8, N2=6). These parameters can be altered provided N1>N2.
|Regress raw||If ON the regression is based on the raw summed data. If OFF (the default) it is based on the binned MSNA data, weighted by the number of points in each bin.|
|Remove artefacts||Removes MSNA signal artefacts.|
|Burst area||Selects the method for calculating burst areas. No criterion = Areas of all the bursts; Criterion = areas of al the bursts, but zero if it has been decided that there is no burst.|
|BRS method||Selects the method for calculating BRS slopes.
1 = plots the y-axis as the mean MSNA area/heart beat vs. diastolic blood pressure bins.
2 = same as option 1 but slopes are statistically weighted by the number of times that a particular value occurs.
3 = plots the y-axis as the burst count (Pulse area is ignored) vs. diastolic blood pressure bins.
4 = same as option 3 but slopes are statistically weighted by the number of times that a particular value occurs. This technique is equivalent to technique described by Kienbaum et al., 2001.
|Integrated nerve input||x-axis is time in seconds.
y-axis is integrated MSNA neurogram.
|Burst area (criterion)||x-axis is time in seconds.
y-axis is the burst area in %*s with/without criterion applied.
|Baroreflex sensitivity||x-axis is diastolic blood pressure in mmHg.
y-axis is AIU/heart beat (BRS method 1 or 2), or bursts/100 heart beats (method 3 or 4).
|Bursts||x-axis is time in seconds.
y-axis is burst amplitude.