post-trigger recorded analysis

Hello,

I am trying to produce a clean recording of evoked responses from rat hippocampal cells. I have set up the recorder in MCRack to start recording 3ms after the trigger signal that initiates the stimulus in order to ignore the artifact. This does not seem to produce any trouble, the file records fine. I can convert it to .abf format and display it in Clampfit fine. However, when I try to replay the file (i.e. for spike sorting or analysis), it shows no activity. If I record the exact same file only set the recorder to start at 0ms after the trigger, or any number before the trigger, it plays back fine. I can see the traces, spikes, and triggers fine. But if I set the recorder at anything positive (i.e. after the trigger), the file just shows a blank white screen in every channel when I try to play it back.

Sorry for being long-winded. I hope someone can help. Let me know if you need any more details and thank you for your help.

Nick

Hello Nick

thank you for your report. The reason why you see no data is due
to a Replayer property. In the current version the Replayer can only
show the triggered data if the trigger event is within the choosen
time interval. For example, if you choose an interval from 2-5 ms relative to the trigger event, the Recorder can not schow the data.

We will change this behaviour in the next release.

Best wishes Dieter

Thanks Dieter.

That's unfortunate to hear, but thank you guys for your hard work updating the little things that users want or need. I look forward to the next release.

Is there any way that I can use the spike sorter to count only the spike that appear within a 50ms window AFTER the stimulus trigger (ie not including the stimulus artifact)?

You cannot trigger the Spike Detector itself by the stimulus event, but the following Analyzer for extracting the spike rate. Add a Trigger Detector to your rack and trigger the Analyzer on the stimulus. Then, you can define the region of interest as you like. It is explained in the MC_Rack Help, but feel free to ask if you have problems with it.

Thanks Christine,

I got it now!