Electrophysiology Experiments

This documentation covers patch electrophysiology experiments using the G4 LED arena in the Reiser Lab at HHMI’s Janelia Research Campus. Experiments were performed by Jin Yong Park of PTR in 2024 and 2025.

TipNew to these experiments?

Start with the Rig Specs page for hardware and software requirements. Then jump to the Quickstart for the protocol you need — each has a prerequisites checklist, experiment workflow, and links to all deep-dive guides.

Protocols

Nested RF Protocol

Created in late 2024–2025 to characterise the receptive field structure and direction selectivity of T4/T5 visual neurons in Drosophila1. Part of a collaboration with the Zipursky lab at UCLA. Based on an earlier protocol by Eyal Gruntman in the Reiser lab2.

This is a two-part protocol:

  • Protocol 1 — coarse receptive field mapping using flashing squares on a grid
  • Protocol 2 — high-resolution RF mapping and direction selectivity using moving bars and small flashes, targeted to the RF location found in P1

See the Nested RF Quickstart for a prerequisites checklist, experiment workflow, and links to all deep-dive pages.

DS Probe Protocol

Created in 2024 to investigate directionally selective responses in less well characterised cell types predicted to have direction selectivity based on dendritic synapse positioning. This analysis was spearheaded by Judith Hoeller of the Romani lab at Janelia.

Shared resources

  • Rig Specs — G4 arena hardware, panel configuration, and calibration
  • G4 Software & GUIs — pattern generator, experiment designer, and experiment conductor tools

Code availability

  • Nested RF Protocol: nested_RF_stimulus repository. This code was cloned locally onto the computer for the G4 electrophysiology rig here: C:\matlabroot\G4_Protocols\nested_RF_stimulus\.
  • DS Probe Protocol: DS_probe_protocol repository.

Running these experiments requires the user to have the G4_Display_Tools repository downloaded locally too.

Data availability

The data from the Nested RF experiments can be found on the Reiser Lab prfs drive here: smb://prfs.hhmi.org/reiserlab/burnettl/Ephys_experiments/nested_RF_stimulus/DATA. The data is then further organised based on sub-type of experiment grouped in the same way as the Experiment Log.

The raw data is also found on the computer in the Ephys rig room within the folder C:\matlabroot\G4_Protocols\nested_RF_protocol2\data.

Please see the following page for details on how the data is saved and stored.

Note

The data within the folder 1DRF contains duplicates of data in other folders. The curated folder contains a subset of experiments that were performed with the same experimental protocol. This data was selected to be used to make the main paper figure for the UCLA collaboration.

Footnotes

  1. Sanfilippo, P., Kim, A.J., Bhukel, A., Yoo, J., Mirshahidi, P.S., Pandey, V., Bevir, H., Yuen, A., Mirshahidi, P.S., Guo, P., Li, H.S., Wohlschlegel, J.A., Aso, Y., Zipursky, S.L. (2024) Mapping of multiple neurotransmitter receptor subtypes and distinct protein complexes to the connectome. Neuron, https://doi.org/10.1016/j.neuron.2023.12.014.↩︎

  2. Gruntman, E., Romani, S. & Reiser, M.B. Simple integration of fast excitation and offset, delayed inhibition computes directional selectivity in Drosophila . Nat Neurosci 21, 250–257 (2018). https://doi.org/10.1038/s41593-017-0046-4↩︎