Learn the fundamentals of Plexon’s OmniPlex software, including how to improve signal quality, data recordability, and approach complex applications of spike sorting. Scientists are faced with numerous challenges when planning and executing research involving high-resolution recordings of neural biopotentials in laboratory animals. Many of these challenges relate to the nuances of the hardware used to collect these measurements, while others touch upon signal acquisition and processing, data management, and downstream analysis. To simplify the research processes, Plexon offers OmniPlex – a turn-key acquisition and data management platform for recording neural biopotentials from acute or chronically implanted electrodes in both anesthetized and awake, behaving animals. Understanding the core features available through this platform, and more importantly, when and how to apply them can help advance your research. The focus of this webinar is to showcase select features of the OmniPlex acquisition software essential to addressing common challenges experienced in the lab. Specifically, Andrew Klein, Director of Sales and Support at Plexon, demonstrates online digital referencing features, including Common Average Referencing (CAR) and Common Median Referencing (CMR), automatic thresholding, and manual and automatic sorting. In addition, attendees learn about features designed to assist researchers and solve common issues, such as recording in a noisy environment, difficulty sorting on many channels, and spike sorting poorly isolated data.

1. Online Neural Data Processing with Plexon
OmniPlex: Referencing, Sorting and Online
Manipulation
Andrew Klein presents the fundamentals of Plexon’s OmniPlex
software, including how to improve signal quality, data
recordability, and approach complex applications of spike sorting.

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3. Online Neural Data Processing with Plexon
OmniPlex: Referencing, Sorting and Online
Manipulation
Andrew Klein
Director of Sales & Support,
Plexon Inc., Dallas, Texas
andrew@plexon.com
PLEXON®, the five-line symbol, CinePlex®, DigiAmp™, Offline Sorter™, OmniPlex®, PlexBright™, PlexStim™ and Radiant™ are registered and
unregistered trademarks of Plexon Inc, Dallas, Texas, USA.
©2017 Plexon Inc. All rights reserved. Other product and company names mentioned are trademarks or registered trademarks of their respective owners.

4. Today’s
Topics
OmniPlex Neural Data
Acquisition system
1. Layout
2. Thresholding and
Extraction
3. Referencing
4. Sorting

5. Important Details:
• OmniPlex Server and PlexControl
• Hardware configuration, data flow, getting started, etc.
• Eight channels of prerecorded data used for demonstration

6. Layout
• Default organization of data
visualization windows
• Customizations
• Savable layout configuration
files (.pxc)
CLICK to watch
the section on
Layouts >>

7. Layout
• Demonstration of layout organization
✓User created layouts for visualizing only the most important information
• Customizable layout of visualization windows
✓Lots of different ways to look at incoming data
• Savable layout configuration files (.pxc)
✓Useful to save layout to be used in the next experiment

8. Thresholding and Extraction
• Standard extraction – a spike’s timestamp
is the time at which it crossed the
threshold
• Aligned extraction – a spike’s timestamp is
the point of the maximum amplitude
• Waveform length
• Prethreshold length
CLICK to watch the
section on Manual
Thresholding >>

9. Automatic Thresholding
• Snapshot of data
• Mean
• Standard deviation (sigma)
CLICK to watch the
section on Automatic
Thresholding >>

10. Thresholding
• Manual extraction
✓ Standard method – time a spike crosses the threshold
✓ Aligned method – time of the maximum amplitude
• Automatic thresholding
✓ Set thresholds across one channel or all channels together
✓ Objectively set the threshold

11. Referencing

12. Hardware Referencing
• Referencing before A/D conversion
• Ground of the electrode or
dedicated reference wire in the
brain
CLICK to watch
the section on
Referencing >>

13. Software (Digital) Referencing
• After A/D conversion, but still online
• Channel referencing
• Common Average Reference (CAR) vs. Common Median Reference
(CMR)

14. Referencing
• Hardware referencing
✓Impacts how data is acquired; using the ground of the implant by default; option
for using a dedicated reference electrode
• Software (digital) referencing
✓Means to improve the quality of already acquired data online
✓Channel referencing
✓Common Average Referencing (CAR) and Common Median Referencing (CMR)

15. Spike Sorting
• Online categorization of waveforms based upon user defined
parameters
• Demonstrate two methods for spike sorting (five total available online)
• Line sorting – sorting based upon the waveform shape
• 2D polygon sorting – sorting based upon the projection of the waveform into
feature space
• Auto-sorting using the Valley Seeking method
CLICK to watch the section on Spike Sorting >>

16. Spike Sorting
• Line sorting
✓Useful method for sorting waveforms, even when the isolation is not ideal
✓Multiple lines, change view, possible to get selective with the sorting
• 2D Polygon sorting
✓Useful method for sorting in feature space
✓Easy to make slight adjustments to the contours online
✓Auto sorting

17. Summary
✓Layouts – useful way for users to configure
the software to look at only the data that is
most important
✓Thresholding – two different means of
extracting spike waveform data from
continuous data online
✓Automatic threshold extraction is possible
✓Differences between hardware
referencing and software (digital)
referencing
✓Two different methods of online
digital referencing
✓Two different methods of online
spike sorting
>> Download the OmniPlex User Guide: www.plexon.com/products/omniplex-d-neural-data-acquisition-system-1 [Resources tab]

18. Q&A
Session
CLICK to watch the Live
Q&A Session with
Andrew Klein >>

19. Andrew Klein
Director of Sales & Support,
Plexon Inc., Dallas, Texas
andrew@plexon.com
Thank You
For additional information on the products and applications
presented during this webinar please visit www.plexon.com