Epileptiform postsynaptic currents in primary culture of rat cortical neurons: Calcium mechanisms
- 88 Downloads
In this study we demonstrate that the primary culture of rat cortical neurons is a convenient model for investigations of epileptogenesis mechanisms and specifically, of the postsynaptic epileptiform currents (EC) reflecting periodical asynchronous glutamate release. In particular, we have revealed that in primary culture of cortical neurons EC can appear spontaneously or can be triggered by the withdrawal of magnesium block of NMDA receptor channels or by shutting down GABAergic inhibition. EC were found to depend on intracellular calcium oscillations. The secondary calcium release from intracellular stores was needed for EC synchronization. EC were suppressed by the influences causing either neuronal calcium overload or decrease of intracellular calcium concentration. Calcium entry into neurons in the case of NMDA receptor hyperactivation or in the case of calcium ionophore ionomycin treatment eliminated EC. The suppression of EC also occurred after a decrease of intracellular calcium concentration induced by BAPTA loaded into the neurons or by stimulation of calcium removal from cells via Na+/Ca2+ exchanger by 1 nM ouabain. Partial dependence of EC on action potential generation was found. Thus, EC in neurons are activated by intracellular periodic calcium waves within a limited concentration window.
Keywordsepileptiform currents primary culture neurons cortex calcium ouabain
Unable to display preview. Download preview PDF.
- 4.Sibarov D.A., Antonov S.M. 2013. The features of postsynaptic currents in primary culture of rat cortical neurons. Ros. Fiziol. Zh. (Rus.). 99(6), 763–775.Google Scholar
- 10.Katz B. 1966. Nerve, muscle and synapse. McGraw Hill Text.Google Scholar
- 11.Zefirov A.L., Cheranov S.Yu. 2000. The molecular mechanisms of quantum mediator secretion in the synapse. Usp. Fiziol. Nauk (Rus.). 31(3), 3–22.Google Scholar
- 14.Myme C.I.O., Sugino K., Turrigiano G.G., Nelson S.B. The NMDA-to-AMPA ratio at synapses onto layer 2/3 pyramidal neurons is conserved across prefrontal and visual cortices. J. Neurophysiol. 90(2), 771–779.Google Scholar
- 15.Mironova E.V., Lukina A.A., Brovtsyna N.B., Krivchenko A.I., Antonov S.M. 2006. Glutamate receptors types defining neurotoxic glutamate action on rat cortex neurons. Zh. Evol. Biokhim. Fiziol. (Rus.). 42, 559–566.Google Scholar
- 31.Sun D.A., Sombati S., Blair R.E., DeLorenzo R.J. Long-lasting alterations in neuronal calcium homeostasis in an in vitro model of stroke-induced epilepsy. Cell Calcium. 35(2), 155–163.Google Scholar
- 35.Blaustein M.P. 1993. Physiological effects of endogenous ouabain: Control of intracellular Ca2+ stores and cell responsiveness. Am. J. Physiol. Cell. Physiol. 264, C1367–C1387.Google Scholar