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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.


Clustering of IPI changes and analysis as a function of the time delay and the area under the quantile-quantile plot.If the IPIs discharged during the closed-loop stimulation sessions are shorter than those of the control sessions (top-left), the area under the qqplot curve are smaller than that for the case when IPIs from the 2 sessions come from similar IPI distributions (top-right). The area values for all 22 experiments where individually plotted against the time delays (bottom). The area values were clustered in 2 groups separated by a critical delay d = 100 ms, cluster A (blue crosses; n = 11) containing time delays from 5 ms to 100 ms (except d = 70 ms which was treated as an outlier) and cluster B (red circles; n = 10) from 100 ms to 280 ms. The areas in cluster A were smaller than those of cluster B.
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pone.0141007.g004: Clustering of IPI changes and analysis as a function of the time delay and the area under the quantile-quantile plot.If the IPIs discharged during the closed-loop stimulation sessions are shorter than those of the control sessions (top-left), the area under the qqplot curve are smaller than that for the case when IPIs from the 2 sessions come from similar IPI distributions (top-right). The area values for all 22 experiments where individually plotted against the time delays (bottom). The area values were clustered in 2 groups separated by a critical delay d = 100 ms, cluster A (blue crosses; n = 11) containing time delays from 5 ms to 100 ms (except d = 70 ms which was treated as an outlier) and cluster B (red circles; n = 10) from 100 ms to 280 ms. The areas in cluster A were smaller than those of cluster B.

Mentions: For all 22 experiments, we observed that there was an increase in the probability of firing shorter/longer IPIs for small/large delays, that is, fish were reacting differently depending on the delay. To further quantify these changes, we calculated the area under the qqplot curve (Fig 4 –top). If shorter IPIs were discharged and the IPI distributions were different in the closed-loop stimulation sessions as compared to the control ones, the area under the curve would be smaller (Fig 4 –top left) than those for the opposite case: similar IPIs and similar distribution (Fig 4 –top right). Hence, small areas mean that fish were affected, increasing their frequency by the activity-dependent stimuli, and large areas mean that they were less affected.


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

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

Clustering of IPI changes and analysis as a function of the time delay and the area under the quantile-quantile plot.If the IPIs discharged during the closed-loop stimulation sessions are shorter than those of the control sessions (top-left), the area under the qqplot curve are smaller than that for the case when IPIs from the 2 sessions come from similar IPI distributions (top-right). The area values for all 22 experiments where individually plotted against the time delays (bottom). The area values were clustered in 2 groups separated by a critical delay d = 100 ms, cluster A (blue crosses; n = 11) containing time delays from 5 ms to 100 ms (except d = 70 ms which was treated as an outlier) and cluster B (red circles; n = 10) from 100 ms to 280 ms. The areas in cluster A were smaller than those of cluster B.
© Copyright Policy
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4608794&req=5

pone.0141007.g004: Clustering of IPI changes and analysis as a function of the time delay and the area under the quantile-quantile plot.If the IPIs discharged during the closed-loop stimulation sessions are shorter than those of the control sessions (top-left), the area under the qqplot curve are smaller than that for the case when IPIs from the 2 sessions come from similar IPI distributions (top-right). The area values for all 22 experiments where individually plotted against the time delays (bottom). The area values were clustered in 2 groups separated by a critical delay d = 100 ms, cluster A (blue crosses; n = 11) containing time delays from 5 ms to 100 ms (except d = 70 ms which was treated as an outlier) and cluster B (red circles; n = 10) from 100 ms to 280 ms. The areas in cluster A were smaller than those of cluster B.
Mentions: For all 22 experiments, we observed that there was an increase in the probability of firing shorter/longer IPIs for small/large delays, that is, fish were reacting differently depending on the delay. To further quantify these changes, we calculated the area under the qqplot curve (Fig 4 –top). If shorter IPIs were discharged and the IPI distributions were different in the closed-loop stimulation sessions as compared to the control ones, the area under the curve would be smaller (Fig 4 –top left) than those for the opposite case: similar IPIs and similar distribution (Fig 4 –top right). Hence, small areas mean that fish were affected, increasing their frequency by the activity-dependent stimuli, and large areas mean that they were less affected.

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.