DOI: 10.5061/dryad.rxwdbrvkj
title: Data and code from: Multisensory integration enhances audiovisual responses in the Mauthner cell

description: Multisensory integration combines information from multiple sensory
 modalities to create a coherent perception of the world. In contexts where
 sensory information is limited or equivocal, it also allows animals to
 integrate individually ambiguous stimuli into a clearer or more accurate
 percept and, thus, react with a more adaptive behavioral response.
 Although responses to multisensory stimuli have been described at the
 neuronal and behavioral levels, a causal or direct link between these two
 is still missing. In this study, we studied the integration of audiovisual
 inputs in the Mauthner cell, a command neuron necessary and sufficient to
 trigger a stereotypical escape response in fish. We performed
 intracellular recordings in adult goldfish while presenting a diverse
 range of stimuli to determine which stimulus properties affect their
 integration. Our results show that stimulus modality, intensity, temporal
 structure, and interstimulus delay affect input summation.
 Mechanistically, we found that the distinct decay dynamics of feedforward
 inhibition triggered by auditory and visual stimuli can account for
 certain aspects of input integration. Altogether, this is a rare example
 of the characterization of multisensory integration in a cell with clear
 behavioral relevance, providing both phenomenological and mechanistic
 insights into how multisensory integration depends on stimulus properties.
description: M-cell intracellular responses to tectal and acoustic stimuli
 were studied in vivo using standard surgical and electrophysiological
 recording techniques (Preuss and Faber, 2003; Preuss et al., 2006; Medan
 et al., 2017). To initiate anesthesia, fish were immersed in 1 liter of
 ice water with 40 mg/l of the general anesthetic tricaine methanesulfonate
 (MS-222, Western Chemical, Ferndale, WA, USA), until the fish ceased to
 swim, lost equilibrium and were unresponsive to a pinch on the tail
 (typically 10–15 min). They were next treated with 20% benzocaine gel
 (Ultradent, South Jordan, UT, USA) at incision sites and pin-holding
 points 5 min prior to surgical procedures. Fish were stabilized in the
 recording chamber by two pins, one on each side of the head, and
 ventilated through the mouth with recirculating, aerated saline at 18°C
 (saline [g/l]: sodium chloride 7.25, potassium chloride 0.38, monosodium
 phosphate monobasic 0.39, magnesium sulfate 0.11, Hepes 4.77; calcium
 chloride 0.24; dextrose 1.01, pH 7.2). The recording chamber was mounted
 inside an opaque, thin-walled tank filled with saline that covered the
 fish up to eye level. The recirculating saline also included a maintenance
 concentration of the anesthetic MS-222 (20 g/l) that does not interfere
 with auditory processing (Palmer and Mensinger, 2004; Cordova and Braun,
 2007). Next, the spinal cord was exposed with a small lateral incision at
 the caudal midbody. Bipolar stimulation electrodes were placed on the
 unopened spinal cord to transmit low-intensity (5–8 V) electrical pulses
 generated by an isolated stimulator (A 360, WPI, Sarasota, FL, USA). This
 allowed antidromic activation of the M-cell axons, as confirmed by a
 visible muscular contraction (twitch). Surgical procedures were performed
 before a muscle paralysis agent was injected, which allows monitoring the
 effectiveness of the anesthetic by watching for an increase of opercula
 movement frequency (largely reduced in deep anesthesia) and
 movements/twitches in response to the surgical procedures. Shortly before
 the recordings started, animals were injected I.M. with D-tubocurarine (1
 μg g−1 b.w.; Abbott Laboratories, Abbott Park, IL, USA) and a small
 craniotomy exposed the medulla for electrophysiological recordings.
 Antidromic stimulation produces a negative potential in the M-cell axon
 cap (typically 15–20 mV), which unambiguously identifies the axon hillock
 and allows intracellular recordings from defined locations along the
 M-cell soma-dendritic membrane (Furshpan and Furukawa, 1962; Furukawa,
 1966; Faber and Korn, 1989). Intracellular recordings were acquired using
 borosilicate glass electrodes (7–10 MΩ) filled with 5 M potassium acetate
 and an Axoclamp-2B amplifier (Axon Instruments, Foster City, CA, USA) in
 current-clamp setting. M-cell responses were acquired with a Digidata
 1440A (Axon Instruments) at 25 kHz. Electrodes were advanced using
 motorized micromanipulators (MP-285; Sutter Instruments, Novato, CA, USA)
 until reaching the axon cap (defined as a site with an extracellular
 M-cell AP field &gt;10 mV). Next, the electrode was moved 50 μm
 lateral and 50 μm posterior to penetrate the somatic region. Only trials
 in which the resting membrane potential was between -90 and -70 mV were
 included in the analysis.
description: # Data and code from: "Multisensory integration enhances audiovisual
 responses in the Mauthner cell"
 [https://doi.org/10.5061/dryad.rxwdbrvkj](https://doi.org/10.5061/dryad.rxwdbrvkj) ## Overview This repository contains data and code associated with the manuscript *"Multisensory Integration Enhances Audiovisual Responses in the Mauthner Cell."* The data and scripts provided here aim to ensure reproducibility and reanalysis of the results presented in the manuscript. For further details, refer to the full manuscript at: [https://doi.org/10.7554/eLife.99424.3](https://doi.org/10.7554/eLife.99424.3) ## Dataset Description ### Experimental Context We performed intracellular recordings of the goldfish Mauthner-cell to investigate audiovisual integration at the cellular level. We focused on measuring the peak and area of the responses in a 12-ms window after the stimulus presentation. The stimuli included auditory pips and stimulation trains in the optic tectum presented separately (unimodal stimulation) or jointly (multimodal stimulation). ## Description of the data and file structure ### Files and variables #### File: Code\_Extraction.m **Description:** Matlab Script to preprocess the raw electrophysiological recordings, detect when the stimuli were presented, and calculate the peak and area of the responses. First, the .abf files are loaded and analyzed, and the variables of interest of each recording are saved in a .mat file. Then, all the .mat files are loaded, and the data is exported as a CSV table. Variables: * SR: acquisition sampling rate, in Hz * ROI: ROI time window duration, in seconds * delayPostTectal: temporal delay between the detection of the tectal pulse and the start of the ROI window, in seconds * tonicDepolarizationShift: time between the end of the time window for measuring the tonic depolarization baseline and the begging of the phasic ROI, in seconds * tonicDepROIwidth: duration of the temporal window for calculating the tonic depolarization, in seconds * tectalSearchY: voltage threshold for detecting a tectal pulse, in Volts * tectalSearchX: number of measurements or samples that will not be considered for detecting a tectal pulse, no units * neuron: string (characters) containing the date and side of the neuron * numberSweeps: number of sweeps (or trials) that each ABF file contains, no units * soundIdx: index of the recording in which the sound was detected, no units * tectalIdx: index of the recording in which the tectal stimulus was detected, no units * ROIstart: index of the recording in which the temporal ROI starts, no units * ROIend: index of the recording in which the temporal ROI ends, no units * area: area under the response to the stimulus in the temporal ROI, in Volts * seconds * peakV: peak voltage of the response to the stimulus in the temporal ROI, in Volts * timeToPeak: time between the start of the temporal ROI and the peak of the response, in seconds * tonicDep: tonic depolarization before the arrival of the stimulus, in Volts The variables area, peakV, timeToPeak, and tonicDep are used to calculate their means across sweeps, and then a prefix containing "M", "T", or "A" is added to indicate if the measurement corresponds to a Multimodal, Tectal, or Auditory trial, respectively. By comparing the Tectal and Auditory responses, the Greater Unimodal response is determined and these set of variables (area, peakV, etc) are also saved with the prefix "GU". For each experimental protocol and for each neuron, a .mat file is saved containing  these variables. Finally, all these .mat files are loaded and used to populate an Excel table with all the information across neurons and protocols.  #### File: abfload.m **Description:** Third-party Matlab Script containing the function used to load the raw .abf files. For details: https://www.mathworks.com/matlabcentral/fileexchange/6190-abfload #### File: Data\_ABFs.zip **Description:** ZIP-compressed folder containing all raw recordings. The name of each containing folder indicates the ID of the cell (date and left or right side), and the name of each file indicates the experimental protocol (i.e. the stimuli presented). Each ABF contains 2 channels: channel 1 contains the recorded voltages of the Mauthner cells (in which the tectal stimulation is also visible and detectable), while channel 2 contains the microphone recording. #### File: Data\_MATs.zip **Description:** ZIP-compressed folder containing .mat files with the measured variables of each recording. The measured variables include: area, peakV, timeToPeak, and tonicDep. Refer to the description of Code_Extraction.m for details on these variables. #### File: Data\_Excel.xlsx **Description:** Excel file containing all the measured variables (columns) obtained for all conditions and all cells (rows). The measured variables include: area, peakV, timeToPeak, and tonicDep. Refer to the description of Code_Extraction.m for details on these variables.