TRPC3 mediates hyperexcitability and epileptiform activity in immature cortex and experimental cortical dysplasia.

Abstract

Neuronal hyperexcitability plays an important role in epileptogenesis. Conditions of low extracellular calcium (Ca) or magnesium (Mg) can induce hyperexcitability and epileptiform activity with unclear mechanisms. Transient receptor potential canonical type 3 (TRPC3) channels play a pivotal role in neuronal excitability and are activated in low-Ca and/or low-Mg conditions to depolarize neurons. TRPC3 staining was highly enriched in immature, but very weak in mature, control cortex, whereas it was strong in dysplastic cortex at all ages. Depolarization and susceptibility to epileptiform activity increased with decreasing Ca and Mg. Combinations of low Ca and low Mg induced larger depolarization in pyramidal neurons and greater susceptibility to epileptiform activity in immature and dysplastic cortex than in mature and control cortex, respectively. Intracellular application of anti-TRPC3 antibody to block TRPC3 channels and bath application of the selective TRPC3 inhibitor Pyr3 greatly diminished depolarization in immature control and both immature and mature dysplastic cortex with strong TRPC3 expression. Epileptiform activity was initiated in low Ca and low Mg when synaptic activity was blocked, and Pyr3 completely suppressed this activity. In conclusion, TRPC3 primarily mediates low Ca- and low Mg-induced depolarization and epileptiform activity, and the enhanced expression of TRPC3 could make dysplastic and immature cortex more hyperexcitable and more susceptible to epileptiform activity.

DOI: 10.1152/jn.00607.2013

Extracted Key Phrases

8 Figures and Tables

Statistics

02004006008002014201520162017
Citations per Year

78 Citations

Semantic Scholar estimates that this publication has 78 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Zhou2014TRPC3MH, title={TRPC3 mediates hyperexcitability and epileptiform activity in immature cortex and experimental cortical dysplasia.}, author={Fu-Wen Zhou and S. N. Roper}, journal={Journal of neurophysiology}, year={2014}, volume={111 6}, pages={1227-37} }