# Ephys sweeps of same cell has different recording length?

**URL:** <https://community.brain-map.org/t/ephys-sweeps-of-same-cell-has-different-recording-length/409>\
**Category:** Science\
**Tags:** experiment-design, electrophysiology, atlas-cell-types\
**Created:** [January 20, 2020, 3:05pm UTC](https://community.brain-map.org/t/ephys-sweeps-of-same-cell-has-different-recording-length/409 "2020-01-20T15:05:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Eskuebler](https://avatars.discourse-cdn.com/v4/letter/e/eb8c5e/32.png) [@Eskuebler](https://community.brain-map.org/u/Eskuebler)\
**Post date:** [January 20, 2020, 3:05pm UTC](https://community.brain-map.org/t/ephys-sweeps-of-same-cell-has-different-recording-length/409/1 "2020-01-20T15:05:20Z")

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Hello,  
Is it possible for the same cell to have different sweep lengths for the same stimulus? Or is this a curation error? I have found some cells that have varying sweep lengths for the long current pulse; but the same acquisition rates.  
Thank you,  
Eric

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**Author:** ![jim](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.brain-map.org/jim/32/206_2.png) [@jim](https://community.brain-map.org/u/jim)\
**Post date:** [January 21, 2020, 5:28pm UTC](https://community.brain-map.org/t/ephys-sweeps-of-same-cell-has-different-recording-length/409/2 "2020-01-21T17:28:26Z")

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Hi Eric - great question.

Regarding the [cell types dataset](http://celltypes.brain-map.org/#ephys): There is no absolute length requirement for individual sweeps (although most are nearly identical). For the long squares the absolute requirements are a current injection with a duration of 1.000 second with a preceding 500 ms of rest (no current injection). Right now the sweep structure can sometimes be difficult to parse, but in the upcoming nwb\_v2 format, epochs are introduced as a way to better define these time blocks. Stay tuned!

Jim