Multisensory integration enhances audiovisual responses in the Mauthner cell
- Instituto de Fisiología y Biología Molecular y Celular, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Argentina
- Department Psychology, Hunter College, City University of New York, United States
- Department Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
Figures
Figure 1 with 1 supplement
M-cell responses to tectal stimulation.
(A) M-cell responses to a 60-Hz tectal train of 200 ms were used to measure the evoked depolarization at 1, 33, 100, and 200 ms after stimulus onset during a 12-ms time window (colored vertical boxes). (A’) Blue and orange bars in the trace show the tonic and phasic components of the response, respectively. The horizontal dotted lines indicate the baseline (bottom) and the potential before the last pulse for quantification of each component. (B) Mean amplitude (± SEM, N=18) of the phasic (shades of orange) and tonic (shades of blue) components of tectal trains for the time windows described in A. (C) M-cell responses to a 100-ms tectal pulse train of 30, 60, 100, or 200 Hz were recorded and quantified as in A, at the end of the pulse. (D) Mean amplitude (± SEM, N=11) of the phasic (shades of orange) and tonic (shades of blue) components of 100 ms tectal trains of different frequencies.
Figure 1—figure supplement 1
Responses in the left- and right-side Mauthner cells.
Representative recordings of left or right M-cell somatic responses to an electric stimulus train delivered to the left tectum (A) or to a short 200 Hz sound pip produced by a loudspeaker placed to the right side of the fish (B). The mean (of three to five repetitions) response is shown in solid color and the diagram of the tectal stimulus or the sound pip are shown below the traces. Dashed boxes indicate the 12 ms time windows following the stimulus where the responses were quantified. Boxplots showing the median, upper and lower quartiles and comparing the response to the same stimulus in the left or right M-cell in 9 fish for the tectal stimulus (C) and 11 fish for the auditory stimulus (D). Markers with the same color in left and right belong to pairs of M-cells of the same fish. No differences were found in the evoked response amplitude between the left and right M-cells or for tectal or auditory stimuli.
Figure 2
Multisensory integration in the M-cell.
(A) Diagram of stimulation (left) and response examples (right). The response examples correspond, to a single acoustic pulse (blue trace) and to their multisensory combination (purple). Below the traces diagram of the stimulation is shown in gray. (B) Stacked bars comparing mean (± SEM, N=17) depolarization evoked by tectal trains of indicated duration (T, orange), auditory (A, blue), or their multisensory combination (purple). (C) Boxplots showing the ratios between the multisensory responses and the maximum unisensory response (MSI/Max). (D) Boxplots showing the ratios between the multisensory responses and the sum of its unisensory components (MSI/Sum). (E–H) As in A–D but for 100 ms tectal trains of different frequencies.
Figure 3
Auditory and tectal feedforward inhibition (FFI) have different decay dynamics.
(A) Diagram of auditory or tectal FFI circuits (center), and the quantification of sensory evoked shunting inhibition as a reduction of M-cell AP amplitude (left, auditory: shaded-blue area; right, tectal: shaded-red area) to a control AP (black trace). (B, C). Boxplots of peak inhibition and time of peak inhibition triggered by acoustic or tectal stimuli. (D) Mean (± SEM, N=19) FFI triggered by tectal and auditory inputs measured in the same M-cells at different time points between 0 and 70 ms post-stimulus. (E) Boxplot of the time elapsed to 50% decay of peak FFI for the auditory (left) and tectal (right) stimuli. (Kruskal–Wallis chi-squared, p = 0.0145). (F) Area below the curve (0–70 ms) for the auditory (left) and tectal (right) stimuli. (Kruskal–Wallis chi-squared, p = 0.0181).
Figure 4
Effect of stimulus sequence and modality on M-cell integration.
(A) Representative responses of one M-cell to two stimuli presented in different trials, or in the same trials with a 50-ms offset. The upper trace shows the M-cell response to an auditory stimulus (S1/A), middle trace corresponds to the response to a single tectal pulse (S2/T), and bottom trace shows the response to an auditory stimulus followed by a tectal stimulus 50 ms later. The area used to quantify each response is shaded in orange (Resp1), dark green (Resp2), or light green (Resp(1 + 2)), respectively. Schematics below each trace the order of stimuli and the area where responses were quantified. The pink bar indicates the time point at which the lingering depolarization of the first response was measured. Note that this analysis was performed for trials in which S1 and S2 could be either auditory or T, resulting in trials AA, TT, TA, and AT sequences. (B) Lingering depolarization after 50 ms of a single auditory pip or a short tectal train. (Kruskal–Wallis rank sum test, p = 0.0188). (C) Integration in the M-cell for pairs of uni- or multisensory stimuli with a 50-ms delay was calculated as the ratio: Resp(1 + 2)/(Resp1 + Resp2).
Figure 5
Multisensory integration of subthreshold unisensory stimuli.
(A) MSI/Max vs. the maximum unisensory response of different multisensory stimuli, irrespective of duration, frequency, or sequence of stimulation (Linear Model, p < 0.0001). (B) Similar to A, but with the MSI/Sum instead vs. the sum of the unisensory responses (Linear Model, p < 0.0001).
Additional files
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Multisensory integration enhances audiovisual responses in the Mauthner cell
eLife 13:RP99424.
https://doi.org/10.7554/eLife.99424.4
