Plexon List Format Version 2 (PL2)

• PL2 refers to the Plexon List Format version 2, a file format used for storing electrophysiological data
• Commonly utilized for neural data acquired from experiments involving multiple electrodes and recording systems
• PL2 files contain timestamped data representing neural events such as action potentials (spikes) and continuous signals like local field potentials (LFPs)
• Developed by Plexon Inc.

Key Features of PL2 Format

• Designed to efficiently store large volumes of neural data.
• Can handle various types of neural data, including spike waveforms, timestamps, and continuous signals.
• Includes metadata describing the experimental setup, recording parameters, and electrode configurations.
• Broadly compatible with Plexon's recording systems and analysis software, as well as other third-party tools for neuroscience research.

Data Organization in PL2 Files

• Contains general information about the recording session
• Describes each channel, including its type (e.g., spike, continuous), sampling rate, and scaling factors
• Stores timestamps and associated data for neural events like spikes and behavioral markers
• Stores continuous signals such as LFPs, EEG, and EMG

Types of Data Stored in PL2 Files

• Spike Data:
  • Timestamps of individual action potentials.
  • Waveforms representing the shape of the action potentials.
  • Information about the electrode or channel from which the spikes were recorded.
  • Cluster identification (if spike sorting has been performed).
• Continuous Data:
  • Voltage values sampled at regular intervals.
  • Sampling rate indicating the number of samples per second.
  • Scaling factors to convert raw voltage values into meaningful units (e.g., microvolts).
• Event Data:
  • Timestamps of specific events, such as stimulus presentations or behavioral responses.
  • Event codes or labels indicating the type of event.
  • Additional data associated with each event, such as stimulus parameters.

Reading and Writing PL2 Files

• Plexon provides a software development kit (SDK) for reading and writing PL2 files in various programming languages.
• Several third-party libraries and toolboxes are available for accessing PL2 data in programming environments such as MATLAB and Python.
• Can be opened and inspected using Plexon's Offline Sorter software, which allows users to visualize and analyze the recorded data.

Applications of PL2 Format

• Used extensively in neuroscience research for studying neural activity and brain function.
• Employed in experiments involving extracellular recordings, such as single-unit recordings and multi-electrode array recordings.
• Utilized in BCI research for decoding neural signals and controlling external devices.
• Applied in clinical neurophysiology for monitoring brain activity and diagnosing neurological disorders.

Advantages of PL2 Format

• Designed to efficiently store large volumes of neural data, making them suitable for long-duration recordings.
• Can accommodate various types of neural data, including spike waveforms, continuous signals, and event markers.
• Includes metadata describing the experimental setup and recording parameters, facilitating data management and analysis.
• Compatible with Plexon's recording systems and analysis software, as well as other third-party tools.

Limitations of PL2 Format

• Is a proprietary format developed by Plexon, which may limit its adoption and interoperability with other software tools.
• The structure of PL2 files can be complex, requiring specialized software or libraries for reading and writing data.
• Files can be large, especially for high-density recordings with many channels and long recording durations.

Tools for Working with PL2 Files

• Software for visualizing, analyzing, and spike sorting neural data in PL2 format.
• A command-line utility included in the Plexon SDK for converting, merging, and manipulating PL2 files.
• Several MATLAB toolboxes are available for reading and writing PL2 files, such as the Plexon SDK for MATLAB.
• Python libraries like Neo can be used to read PL2 files and integrate them into data analysis pipelines.

PL2 vs. PLX

• PLX is an earlier format from Plexon, and PL2 is the newer format.
• PL2 generally offers improvements in data storage, organization, and handling of large datasets compared to PLX.

Plexon List Format Version 2 (PL2) is a file format used for storing electrophysiological data, especially neural data from experiments with multiple electrodes. PL2 files contain timestamped data representing neural events like action potentials and continuous signals, with metadata on experimental setup and recording parameters.