spikeinterface-electrophysiology

SpikeInterface — Unified Extracellular Electrophysiology Framework

Overview

SpikeInterface provides a common Python API to read extracellular recordings from 20+ file formats, preprocess raw voltage traces, run 10+ spike sorters, postprocess and quality-control sorted units, and export results — all without format-specific code. Its modular design lets users swap sorters, formats, and preprocessing steps without rewriting pipelines. SpikeInterface is built around lazy, chainable objects: a Recording holds raw data, a Sorting holds spike times, and a SortingAnalyzer ties them together for waveform and metric computation.

When to Use

• Loading recordings from multiple acquisition systems (SpikeGLX, OpenEphys, Intan, NWB, Maxwell MEA, Blackrock) with a unified API rather than format-specific parsers
• Running the same preprocessing and sorting pipeline across experiments recorded on different hardware
• Comparing two or more spike sorters on the same recording to assess agreement and choose the best output
• Running containerized sorters (Kilosort, IronClust, MountainSort5) via Docker or Singularity without local installation
• Computing standard quality metrics (SNR, ISI violations, firing rate, presence ratio, amplitude cutoff) and applying threshold-based curation
• Validating spike-sorting accuracy against synthetic or hybrid ground-truth recordings
• Exporting sorted results to NWB for data sharing or to Phy for manual curation
• Use neuropixels-analysis instead for a complete Neuropixels-specific Kilosort4 workflow including PSTH computation, tuning curves, and population decoding
• For EEG, ECG, or other biosignal processing (not spike sorting), use neurokit2 instead

Prerequisites

• Python packages: spikeinterface[full]>=0.101, probeinterface, numpy, matplotlib
• Optional sorter deps: kilosort (pip), or Docker/Singularity for containerized sorters
• Data requirements: raw binary recording files plus probe geometry (.prb, .json, or auto-detected from format)
• Hardware: GPU required for Kilosort4; all other sorters run on CPU

pip install "spikeinterface[full]>=0.101" probeinterface
# Optional: Kilosort4 Python package
pip install kilosort
# Optional: Phy for manual curation
pip install phy

Quick Start

import spikeinterface.full as si
import spikeinterface.preprocessing as spre
import spikeinterface.sorters as ss
import spikeinterface.qualitymetrics as sqm

# Load, preprocess, sort, and inspect quality metrics in 10 lines
recording = si.read_openephys("/data/session_001", stream_name="Signals CH")
recording_pp = spre.bandpass_filter(
    spre.common_reference(recording, reference="global", operator="median"),
    freq_min=300, freq_max=6000,
)
sorting = ss.run_sorter("spykingcircus2", recording_pp, output_folder="./sc2_out")
analyzer = si.create_sorting_analyzer(sorting, recording_pp, folder="./analyzer")
analyzer.compute(["random_spikes", "waveforms", "templates", "noise_levels"])
metrics = sqm.compute_quality_metrics(analyzer, metric_names=["snr", "firing_rate", "isi_violation"])
print(metrics.describe())

Core API

Module 1: Recording I/O

SpikeInterface wraps every acquisition format behind a common BaseRecording interface. Once loaded, all objects expose the same methods regardless of origin format.

import spikeinterface.full as si

# SpikeGLX (.bin + .meta)
recording_sglx = si.read_spikeglx("/data/session_001", stream_name="imec0.ap")

# OpenEphys (binary or classic)
recording_oe = si.read_openephys("/data/oe_session", stream_name="Signals CH")

# NWB file
recording_nwb = si.read_nwb_recording("/data/recording.nwb",
                                       electrical_series_name="ElectricalSeries")

# Intan RHD/RHS
recording_intan = si.read_intan("/data/session.rhd", stream_name="RHn")

# Inspect any recording with the same API
print(f"Format:       {type(recording_sglx).__name__}")
print(f"Channels:     {recording_sglx.get_num_channels()}")
print(f"Sampling rate:{recording_sglx.get_sampling_frequency()} Hz")
print(f"Duration:     {recording_sglx.get_total_duration():.1f} s")
print(f"Probe:        {recording_sglx.get_probe().name}")

# List available streams before loading (useful when a file has multiple streams)
streams = si.get_neo_streams("spikeglx", "/data/session_001")
print("Available streams:", streams)
# e.g. ['imec0.ap', 'imec0.lf', 'nidq']

# Select a time slice (lazy, no data loaded until get_traces() is called)
recording_slice = recording_sglx.frame_slice(
    start_frame=0,
    end_frame=int(60 * recording_sglx.get_sampling_frequency()),  # first 60 s
)
print(f"Sliced duration: {recording_slice.get_total_duration():.1f} s")

Module 2: Preprocessing

Preprocessing functions return new Recording objects wrapping the original; the chain is applied lazily when data is read. This keeps memory usage low even for multi-hour recordings.

import spikeinterface.preprocessing as spre

# 1. Common median reference — removes shared noise across all channels
recording_cmr = spre.common_reference(recording_sglx,
                                       reference="global",
                                       operator="median")

# 2. Bandpass filter for action potentials (300–6000 Hz typical)
recording_filt = spre.bandpass_filter(recording_cmr,
                                       freq_min=300,
                                       freq_max=6000)

# 3. Remove bad channels automatically (coherence-based detection)
recording_clean, removed_ids = spre.remove_bad_channels(recording_filt,
                                                          method="coherence+psd")
print(f"Removed {len(removed_ids)} bad channels: {removed_ids}")
print(f"Clean channels: {recording_clean.get_num_channels()}")

# Whitening — decorrelates channels; recommended before template-matching sorters
recording_white = spre.whiten(recording_clean, mode="local")

# Phase shift correction for Neuropixels (samples acquired with small time offsets)
recording_shifted = spre.phase_shift(recording_clean)

# Inspect a short snippet of preprocessed data
traces = recording_white.get_traces(start_frame=0, end_frame=3000, segment_index=0)
print(f"Trace snippet shape: {traces.shape}")   # (3000, n_channels)
print(f"Trace range: [{traces.min():.2f}, {traces.max():.2f}] µV")

Module 3: Spike Sorting

ss.run_sorter() wraps every supported sorter behind a uniform call signature. Sorter-specific parameters are passed as keyword arguments; all other pipeline steps are identical.

import spikeinterface.sorters as ss
from pathlib import Path

# List all sorters available in the current environment
available = ss.available_sorters()
print("Available sorters:", available)

# List sorters that can run without local installation (via container)
installed = ss.installed_sorters()
print("Installed locally:", installed)

# Run SpykingCircus2 (CPU, no external deps)
sorting_sc2 = ss.run_sorter(
    "spykingcircus2",
    recording_clean,
    output_folder=Path("./sorter_output/sc2"),
    remove_existing_folder=True,
    verbose=True,
)
print(f"SpykingCircus2 units: {len(sorting_sc2.get_unit_ids())}")

# Run Kilosort4 via Docker container (no local GPU/MATLAB required)
sorting_ks4 = ss.run_sorter(
    "kilosort4",
    recording_clean,
    output_folder=Path("./sorter_output/ks4"),
    singularity_image=False,   # use Docker; set True for Singularity
    docker_image=True,
    remove_existing_folder=True,
    # Kilosort4-specific parameters
    nblocks=5,
    Th_learned=8,
    do_correction=True,
)
print(f"Kilosort4 units: {len(sorting_ks4.get_unit_ids())}")

# Run MountainSort5 (CPU, fast, good for tetrode/low-channel-count probes)
sorting_ms5 = ss.run_sorter(
    "mountainsort5",
    recording_clean,
    output_folder=Path("./sorter_output/ms5"),
    scheme="2",          # scheme 2 is recommended for high-density