In this run obtained during fictive scratch, intracellular data from 2MNs 
were collected as (continuous) waveforms along with several ENGs.  During 
this run activity in extensor nerves dropped out for a few cycles.

Question: what is the averaged intracellular (LDP) waveform of a MN when 
the CPG fails to recruit MN populations for a few cycles?

Since WFs are continuous data collections, the first task is to divide them 
up into short sections. We need to chop up the continuous WF into discrete 
sections that can then be sorted and averaged together. In Analysis this is 
accomplished by "reframing" the data.

Reframing needs a "trigger" point on which to chop up the waveform. In
this case the trigger is the burst of activity in the PBSt ENG during
each scratch cycle.  Using the spike triggering in the WF Activity
section of Analysis, the beginning of ENG bursts are treated as "spikes",
i.e. discrete events.  Using the onset of ENG activity as the trigger
point, the software then divides the selected WFs into sections (plus
and minus from the trigger).  These sections are now "frames" consisting
of traces on which all frame based analyses can be performed.  In this
case each frame is one step cycle with time "0" (the trigger) being
the onset of PBSt ENG activity.  WF data falling outside of the frame
"window" is deleted but the original WFs remain intact.

The next step is to "mark" the frames to fall into one of up to three 
groups.  This is called "tagging" in Analysis jargon.  Frames then can be 
included or excluded from averaging based on these tags.  The setting of 
tags can be a bit tedious but by using the Raw Waveform Display and 
displaying the accompanying frames, one can select only those frames in 
which particular events occurred.  In this case, the LDPs 
(ScratchDrivePotentials, actually) in 2 MNs were grouped into those 
occurring with and without deletions of extensor ENG activity.  In this 
example, all frames were first assigned one "tag". The tag value of those 
few occurring during extensor deletions were then changed.

The final step is to make averages for control and deleted scratch cycles 
using "Analysis - Trace average - By frame"

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Question: what is the averaged intracellular (LDP) waveform of a MN when 
the CPG spontaneously fails to recruit MN populations for a few cycles?

Data set: continuous WF data of ENGs and 2 intracellular MN records during 
a bout of fictive scratch.

Objectives:
1) change continuous WF data into shorter sections (frames) centered about 
a point of interest occurring in waveform. In this case this is ENG 
activity in a scratch cycle but it could be anything that can be 
differentiated using a window discriminator.

2) use the spike triggering in the WF Activity section of Analysis to
treat points in a continuous WF (eg. ENG) as discrete "spikes"

2) assign (tag) frames to be in a subset of data.  In this case the LDPs 
are separated into those during normal scratch cycles and those where 
extensor deletions occurred.

3) make separate frame averages based on these tags.

4) put averages obtained under 2 (or more) conditions together into one 
file using the Appendrun program for further analysis and display using 
Quickmeasure (or Raster or other programs that handle Frame data).

5) automatically display cycle measurements such as onset and duration 
times and export these values to a spreadsheet.

6) produce a graph of LDP amplitude vs cycle duration

7) use Dumprun to extract run data as ascii values

