ndx-icephys-meta Extension for NWB

This extension implements the icephys extension proposal described here. The extension is intended to evaluate and explore the practical use of the proposed changes as well as to provide a reference implementation with the goal to ease integration of the proposed changes with NWB.

Install

pip install

The extension is available on pip and can be installed via:

pip install ndx-icephys-meta

The extension is also listed in the NDX catalog. See here for the catalog metadata record.

developer install

python setup.py develop

Building the spec documentation

cd docs
make html

This generates the specification docs directly from the YAML specifciation in the spec folder. The generated docs are stored in /docs/build

Running the unit tests

python src/pynwb/ndx_icephys_meta/test/test_icephys.py

Content

• spec/ : YAML specification of the extension
• docs/ : Sources for building the specification docs from the YAML spec
• src/spec/create_extension_spec.py : Python source file for creating the specification
• src/pynwb/ : Sources for Python extensions and examples
  • ndx_icephys_meta : Python package with extensions to PyNWB for read/write of extension data
  • ndx_icephys_meta/test : Unit test for the Python extension
  • ndx_icephys_meta/icephys.py : PyNWB Container classes
  • ndx_icephys_meta/io/icephys.py : PyNWB ObjectMapper classes
  • examples : Examples illustrating the use of the extension in Python

Example

Examples for the Python extension are available at src/pynwb/examples. The unit tests in src/pynwb/ndx_icephys_meta/test can also serve as additional examples.

The following shows a simple example. The steps with (A) - (E) in the comments are the main new steps for this extension. The other parts of the code are standard NWB code.

from datetime import datetime
from dateutil.tz import tzlocal
import numpy as np
from pynwb.icephys import VoltageClampStimulusSeries, VoltageClampSeries
from pynwb import NWBHDF5IO
from ndx_icephys_meta.icephys import ICEphysFile  # Import the extension

# Create an ICEphysFile
nwbfile = ICEphysFile(session_description='my first recording',
                      identifier='EXAMPLE_ID',
                      session_start_time=datetime.now(tzlocal()))

# Add a device
device = nwbfile.create_device(name='Heka ITC-1600')

# Add an intracellular electrode
electrode = nwbfile.create_icephys_electrode(
    name="elec0",
    description='a mock intracellular electrode',
    device=device)

# Create an ic-ephys stimulus
stimulus = VoltageClampStimulusSeries(
            name="stimulus",
            data=[1, 2, 3, 4, 5],
            starting_time=123.6,
            rate=10e3,
            electrode=electrode,
            gain=0.02)

# Create an ic-response
response = VoltageClampSeries(
            name='response',
            data=[0.1, 0.2, 0.3, 0.4, 0.5],
            conversion=1e-12,
            resolution=np.nan,
            starting_time=123.6,
            rate=20e3,
            electrode=electrode,
            gain=0.02,
            capacitance_slow=100e-12,
            resistance_comp_correction=70.0)

# (A) Add an intracellular recording to the file
#     NOTE: We can optionally define time-ranges for the stimulus/response via
#     the corresponding option _start_index and _index_count parameters.
#     NOTE: It is allowed to add a recording with just a stimulus or a response
#     NOTE: We can  add custom columns to any of our tables in steps (A)-(E)
ir_index = nwbfile.add_intracellular_recording(electrode=electrode,
                                               stimulus=stimulus,
                                               response=response)

# (B) Add a list of sweeps to the sweeps table
sweep_index = nwbfile.add_icephys_simultaneous_recording(recordings=[ir_index, ])

# (C) Add a list of simultaneous recordings table indices as a sequential recording
sequence_index = nwbfile.add_icephys_sequential_recording(
    simultaneous_recordings=[sweep_index, ],
    stimulus_type='square')

# (D) Add a list of sequential recordings table indices as a repetition
run_index = nwbfile.add_icephys_repetition(sequential_recordings=[sequence_index, ])

# (E) Add a list of repetition table indices as a experimental condition
nwbfile.add_icephys_experimental_condition(repetitions=[run_index, ])

# Write our test file
testpath = "test_icephys_file.h5"
with NWBHDF5IO(testpath, 'w') as io:
    io.write(nwbfile)

# Read the data back in
with NWBHDF5IO(testpath, 'r') as io:
    infile = io.read()
    print(infile)