Limits...
Peripheral sensory coding through oscillatory synchrony in weakly electric fish.

Baker CA, Huck KR, Carlson BA - Elife (2015)

Bottom Line: We found that oscillating receptors respond to electric pulses by resetting their phase, resulting in transient synchrony among receptors that encodes signal timing and location, but not waveform.These receptors were most sensitive to frequencies found only in the collective signals of groups of conspecifics, and this was correlated with increased behavioral responses to these frequencies.Our findings provide the first evidence for sensory coding through oscillatory synchrony.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Washington University in St. Louis, St. Louis, United States.

ABSTRACT
Adaptations to an organism's environment often involve sensory system modifications. In this study, we address how evolutionary divergence in sensory perception relates to the physiological coding of stimuli. Mormyrid fishes that can detect subtle variations in electric communication signals encode signal waveform into spike-timing differences between sensory receptors. In contrast, the receptors of species insensitive to waveform variation produce spontaneously oscillating potentials. We found that oscillating receptors respond to electric pulses by resetting their phase, resulting in transient synchrony among receptors that encodes signal timing and location, but not waveform. These receptors were most sensitive to frequencies found only in the collective signals of groups of conspecifics, and this was correlated with increased behavioral responses to these frequencies. Thus, different perceptual capabilities correspond to different receptor physiologies. We hypothesize that these divergent mechanisms represent adaptations for different social environments. Our findings provide the first evidence for sensory coding through oscillatory synchrony.

No MeSH data available.


Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.(A) The EOD rate over time in response to a single conspecific EOD (top) and a train of 10 conspecific EODs at constant 0.5-ms IPI in one P. tenuicauda. Stimuli were delivered at time = 0 s. We defined the baseline response as the average EOD rate between 4.8 s and 0.2 s before stimulus onset. We measured the maximum increase and decrease in EOD rate relative to baseline that occurred in a window starting 0.2 s before stimulus onset and ending 1.2 s after stimulus offset. (B) Same as A for one P. microphthalmus. (C) A normalized measure of EOD rate increases to constant IPI trains of conspecific EODs vs IPI during behavioral playback experiments for a species with oscillating receptors (P. tenuicauda) and a congeneric species with spiking receptors (P. microphthalmus). *, repeated-measures ANOVA, interaction between species and IPI, p < 0.01. (D) Same as C for EOD rate decreases. Each point represents the mean across fish and error bars represent S.E.M.DOI:http://dx.doi.org/10.7554/eLife.08163.011
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4522468&req=5

fig9: Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.(A) The EOD rate over time in response to a single conspecific EOD (top) and a train of 10 conspecific EODs at constant 0.5-ms IPI in one P. tenuicauda. Stimuli were delivered at time = 0 s. We defined the baseline response as the average EOD rate between 4.8 s and 0.2 s before stimulus onset. We measured the maximum increase and decrease in EOD rate relative to baseline that occurred in a window starting 0.2 s before stimulus onset and ending 1.2 s after stimulus offset. (B) Same as A for one P. microphthalmus. (C) A normalized measure of EOD rate increases to constant IPI trains of conspecific EODs vs IPI during behavioral playback experiments for a species with oscillating receptors (P. tenuicauda) and a congeneric species with spiking receptors (P. microphthalmus). *, repeated-measures ANOVA, interaction between species and IPI, p < 0.01. (D) Same as C for EOD rate decreases. Each point represents the mean across fish and error bars represent S.E.M.DOI:http://dx.doi.org/10.7554/eLife.08163.011

Mentions: If oscillating receptors facilitate detection of communication signals produced by a group of individuals, then species with oscillating receptors should exhibit selective behavioral responses to submillisecond IPIs, and species with spiking receptors should not. To test this hypothesis, we performed behavioral playback experiments in which we presented a single fish with a train of 10 conspecific EODs at constant IPIs (Figure 9).10.7554/eLife.08163.011Figure 9.Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.


Peripheral sensory coding through oscillatory synchrony in weakly electric fish.

Baker CA, Huck KR, Carlson BA - Elife (2015)

Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.(A) The EOD rate over time in response to a single conspecific EOD (top) and a train of 10 conspecific EODs at constant 0.5-ms IPI in one P. tenuicauda. Stimuli were delivered at time = 0 s. We defined the baseline response as the average EOD rate between 4.8 s and 0.2 s before stimulus onset. We measured the maximum increase and decrease in EOD rate relative to baseline that occurred in a window starting 0.2 s before stimulus onset and ending 1.2 s after stimulus offset. (B) Same as A for one P. microphthalmus. (C) A normalized measure of EOD rate increases to constant IPI trains of conspecific EODs vs IPI during behavioral playback experiments for a species with oscillating receptors (P. tenuicauda) and a congeneric species with spiking receptors (P. microphthalmus). *, repeated-measures ANOVA, interaction between species and IPI, p < 0.01. (D) Same as C for EOD rate decreases. Each point represents the mean across fish and error bars represent S.E.M.DOI:http://dx.doi.org/10.7554/eLife.08163.011
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522468&req=5

fig9: Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.(A) The EOD rate over time in response to a single conspecific EOD (top) and a train of 10 conspecific EODs at constant 0.5-ms IPI in one P. tenuicauda. Stimuli were delivered at time = 0 s. We defined the baseline response as the average EOD rate between 4.8 s and 0.2 s before stimulus onset. We measured the maximum increase and decrease in EOD rate relative to baseline that occurred in a window starting 0.2 s before stimulus onset and ending 1.2 s after stimulus offset. (B) Same as A for one P. microphthalmus. (C) A normalized measure of EOD rate increases to constant IPI trains of conspecific EODs vs IPI during behavioral playback experiments for a species with oscillating receptors (P. tenuicauda) and a congeneric species with spiking receptors (P. microphthalmus). *, repeated-measures ANOVA, interaction between species and IPI, p < 0.01. (D) Same as C for EOD rate decreases. Each point represents the mean across fish and error bars represent S.E.M.DOI:http://dx.doi.org/10.7554/eLife.08163.011
Mentions: If oscillating receptors facilitate detection of communication signals produced by a group of individuals, then species with oscillating receptors should exhibit selective behavioral responses to submillisecond IPIs, and species with spiking receptors should not. To test this hypothesis, we performed behavioral playback experiments in which we presented a single fish with a train of 10 conspecific EODs at constant IPIs (Figure 9).10.7554/eLife.08163.011Figure 9.Behavioral responses reveal tuning to submillisecond IPIs in a species with oscillating receptors.

Bottom Line: We found that oscillating receptors respond to electric pulses by resetting their phase, resulting in transient synchrony among receptors that encodes signal timing and location, but not waveform.These receptors were most sensitive to frequencies found only in the collective signals of groups of conspecifics, and this was correlated with increased behavioral responses to these frequencies.Our findings provide the first evidence for sensory coding through oscillatory synchrony.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Washington University in St. Louis, St. Louis, United States.

ABSTRACT
Adaptations to an organism's environment often involve sensory system modifications. In this study, we address how evolutionary divergence in sensory perception relates to the physiological coding of stimuli. Mormyrid fishes that can detect subtle variations in electric communication signals encode signal waveform into spike-timing differences between sensory receptors. In contrast, the receptors of species insensitive to waveform variation produce spontaneously oscillating potentials. We found that oscillating receptors respond to electric pulses by resetting their phase, resulting in transient synchrony among receptors that encodes signal timing and location, but not waveform. These receptors were most sensitive to frequencies found only in the collective signals of groups of conspecifics, and this was correlated with increased behavioral responses to these frequencies. Thus, different perceptual capabilities correspond to different receptor physiologies. We hypothesize that these divergent mechanisms represent adaptations for different social environments. Our findings provide the first evidence for sensory coding through oscillatory synchrony.

No MeSH data available.