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Delay-Dependent Response in Weakly Electric Fish under Closed-Loop Pulse Stimulation.

Forlim CG, Pinto RD, Varona P, Rodríguez FB - PLoS ONE (2015)

Bottom Line: In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals.Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics.We also discuss the implications of these findings in the context of information processing in weakly electric fish.

View Article: PubMed Central - PubMed

Affiliation: Laboratório Fenômenos Não-Lineares, Instituto de Física, Universidade de São Paulo, São Paulo, Brazil.

ABSTRACT
In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals. Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics. To investigate how the inter pulse intervals vary in response to external stimuli, we compare the response to a simple closed-loop stimulation protocol and the signals generated without electrical stimulation. The activity-dependent stimulation protocol explores different stimulus delivery delays relative to the fish's own electric discharges. We show that there is a critical time delay in this closed-loop interaction, as the largest changes in inter pulse intervals occur when the stimulation delay is below 100 ms. We also discuss the implications of these findings in the context of information processing in weakly electric fish.

No MeSH data available.


IPI changes depend on the stimulus time delay.Quantile-quantile plot of IPIs during control and the closed-loop stimulation sessions for 4 different experiments. The black line represents the reference line y = x, slope = 1. Top-left–the IPIs from the control session and stimulus session with time delay d = 10 ms came from different distributions. Most of the points (blue) were under the reference line indicating that IPIs discharged during the stimulus session were shorter than those of the control session in the range from 50 ms to 375 ms. Bottom-left–The IPIs discharged during the 2 sessions come from similar distribution, IPIs discharged during the stimulus session were ~20ms shorter in a range from 15 to 200 ms. Top-right–IPIs ranging 60 ms to 150 ms came from similar distributions in the control session and in the closed-loop stimulation session. For longer IPIs (>150 ms), the control session presented always shorter IPIs than those of the closed-loop stimulation session, the opposite happened to IPIs shorter than 60 ms. Bottom-right–IPIs from both sessions came from shifted distributions.
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pone.0141007.g003: IPI changes depend on the stimulus time delay.Quantile-quantile plot of IPIs during control and the closed-loop stimulation sessions for 4 different experiments. The black line represents the reference line y = x, slope = 1. Top-left–the IPIs from the control session and stimulus session with time delay d = 10 ms came from different distributions. Most of the points (blue) were under the reference line indicating that IPIs discharged during the stimulus session were shorter than those of the control session in the range from 50 ms to 375 ms. Bottom-left–The IPIs discharged during the 2 sessions come from similar distribution, IPIs discharged during the stimulus session were ~20ms shorter in a range from 15 to 200 ms. Top-right–IPIs ranging 60 ms to 150 ms came from similar distributions in the control session and in the closed-loop stimulation session. For longer IPIs (>150 ms), the control session presented always shorter IPIs than those of the closed-loop stimulation session, the opposite happened to IPIs shorter than 60 ms. Bottom-right–IPIs from both sessions came from shifted distributions.

Mentions: To quantify the changes in the IPI distributions between control and stimulus sessions, we show the quantile-quantile plots (qqplot) [35], in Fig 3, a well-known statistics tool to measure differences in distributions from 2 datasets in Fig 3, for 4 different experiments (presented in Fig 2). If the qqplot curve show points that are not forming a straight line, the IPIs from the stimulus sessions and control sessions come from different IPI distributions, that is, the closed-loop stimulation session largely affected the fish.


Delay-Dependent Response in Weakly Electric Fish under Closed-Loop Pulse Stimulation.

Forlim CG, Pinto RD, Varona P, Rodríguez FB - PLoS ONE (2015)

IPI changes depend on the stimulus time delay.Quantile-quantile plot of IPIs during control and the closed-loop stimulation sessions for 4 different experiments. The black line represents the reference line y = x, slope = 1. Top-left–the IPIs from the control session and stimulus session with time delay d = 10 ms came from different distributions. Most of the points (blue) were under the reference line indicating that IPIs discharged during the stimulus session were shorter than those of the control session in the range from 50 ms to 375 ms. Bottom-left–The IPIs discharged during the 2 sessions come from similar distribution, IPIs discharged during the stimulus session were ~20ms shorter in a range from 15 to 200 ms. Top-right–IPIs ranging 60 ms to 150 ms came from similar distributions in the control session and in the closed-loop stimulation session. For longer IPIs (>150 ms), the control session presented always shorter IPIs than those of the closed-loop stimulation session, the opposite happened to IPIs shorter than 60 ms. Bottom-right–IPIs from both sessions came from shifted distributions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608794&req=5

pone.0141007.g003: IPI changes depend on the stimulus time delay.Quantile-quantile plot of IPIs during control and the closed-loop stimulation sessions for 4 different experiments. The black line represents the reference line y = x, slope = 1. Top-left–the IPIs from the control session and stimulus session with time delay d = 10 ms came from different distributions. Most of the points (blue) were under the reference line indicating that IPIs discharged during the stimulus session were shorter than those of the control session in the range from 50 ms to 375 ms. Bottom-left–The IPIs discharged during the 2 sessions come from similar distribution, IPIs discharged during the stimulus session were ~20ms shorter in a range from 15 to 200 ms. Top-right–IPIs ranging 60 ms to 150 ms came from similar distributions in the control session and in the closed-loop stimulation session. For longer IPIs (>150 ms), the control session presented always shorter IPIs than those of the closed-loop stimulation session, the opposite happened to IPIs shorter than 60 ms. Bottom-right–IPIs from both sessions came from shifted distributions.
Mentions: To quantify the changes in the IPI distributions between control and stimulus sessions, we show the quantile-quantile plots (qqplot) [35], in Fig 3, a well-known statistics tool to measure differences in distributions from 2 datasets in Fig 3, for 4 different experiments (presented in Fig 2). If the qqplot curve show points that are not forming a straight line, the IPIs from the stimulus sessions and control sessions come from different IPI distributions, that is, the closed-loop stimulation session largely affected the fish.

Bottom Line: In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals.Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics.We also discuss the implications of these findings in the context of information processing in weakly electric fish.

View Article: PubMed Central - PubMed

Affiliation: Laboratório Fenômenos Não-Lineares, Instituto de Física, Universidade de São Paulo, São Paulo, Brazil.

ABSTRACT
In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals. Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics. To investigate how the inter pulse intervals vary in response to external stimuli, we compare the response to a simple closed-loop stimulation protocol and the signals generated without electrical stimulation. The activity-dependent stimulation protocol explores different stimulus delivery delays relative to the fish's own electric discharges. We show that there is a critical time delay in this closed-loop interaction, as the largest changes in inter pulse intervals occur when the stimulation delay is below 100 ms. We also discuss the implications of these findings in the context of information processing in weakly electric fish.

No MeSH data available.