NEST Conference 2022

Balance and adaptation in neuronal systems

K-4

24 Jun 2022, 12:00

25m

Virtual

Keynote Main track Keynote

Speaker

Anna Levina (University of Tübingen, Mathematisch-Naturwissenschaftliche Fakultät, Fachbereich Informatik, Germany)

Description

The balance of excitation and inhibition in neuronal circuits is essential for stable dynamics. This is probably why various brain regions show distinct and highly conserved ratios of excitatory and inhibitory neurons. However, it is unclear if biological neuronal networks with artificial ratios of inhibitory and excitatory neurons would exhibit changes in dynamics. Moreover, it is unclear whether the artificial ratios would jeopardize the balance of excitation and inhibition on a synaptic level. To investigate these questions, we recorded the Ca-activity of hippocampal cultures with various fractions
of inhibitory neurons. All cultures developed spontaneous network bursting. The cultures with various fractions of inhibitory neurons showed stable mean inter-burst intervals. However, the variance of inter-burst intervals grew with the number of inhibitory neurons. We reproduced the results of experiments in a model network of adaptive leaky integrate-and-fire neurons with different numbers of inhibitory neurons but the balanced numbers of excitatory and inhibitory synapses.
Overall, our results suggest that hippocampal cultures with various cellular compositions tend to maintain the balance of excitation and inhibition.

Acknowledgements

This work is supported by the Minerva Foundation (Grant Number 124041), the Clore Center for Biological Physics, the Israel Science Foundation (Grant Number 1385/16), the Bundesministeriums für Bildung und Forschung through the Tübingen AI Center (Förderkennzeichen: 01IS18039B), and the Sofja Kovalevskaja Award of Humboldt Foundation.

References

Sukenik, N., Vinogradov, O., Weinreb, E., Segal, M., Levina, A. and Moses, E., 2021. Neuronal circuits overcome imbalance in excitation and inhibition by adjusting connection numbers. /Proceedings of the National Academy of Sciences/, /118/(12), p.e2018459118.