Membrane potential depolarization causes alterations in neuron arrangement and connectivity in cocultures

Brain and Behavior

Nurdan Özkucur²  Kyle P. Quinn²  Jin C. Pang¹  Chuang Du²  Irene Georgakoudi²  Eric Miller¹  Michael Levin³ 

[1] Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts;Department of Biomedical Engineering, Tufts University, Medford, Massachusetts;Biology Department, Tufts University, Medford, Massachusetts

关键词: Automated cluster analysis;    cell resting membrane potential;    connectivity;    cortical neurons;    neuron assemblies;   

DOI  :  10.1002/brb3.295

来源: Wiley

【 摘 要 】

Abstract

Background

The disruption of neuron arrangement is associated with several pathologies. In contrast to action potentials, the role of resting potential (V_mem) in regulating connectivity remains unknown.

Methods

Neuron assemblies were quantified when their V_mem was depolarized using ivermectin (Ivm), a drug that opens chloride channels, for 24 h in cocultures with astrocytes. Cell aggregation was analyzed using automated cluster analysis methods. Neural connectivity was quantified based on the identification of isolated somas in phase-contrast images using image processing. V_mem was measured using voltage-sensitive dyes and whole-cell patch clamping. Immunocytochemistry and Western blotting were used to detect changes in the distribution and production of the proteins.

Results

Data show that V_mem regulates cortical tissue shape and connectivity. Automated cluster analysis methods revealed that the degree of neural aggregation was significantly increased (0.26 clustering factor vs. 0.21 in controls, P ≤ 0.01). The number of beta-tubulin III positive neural projections was also significantly increased in the neural aggregates in cocultures with Ivm. Hyperpolarized neuron cells formed fewer connections (33% at 24 h, P ≤ 0.05) compared to control cells in 1-day cultures. Glia cell densities increased (33.3%, P ≤ 0.05) under depolarizing conditions.

Conclusion

V_mem can be a useful tool to probe neuronal cells, disease tissues models, and cortical tissue arrangements.

【 授权许可】

CC BY   
© 2014 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.