Early-life epileptiform discharges exert both rapid and long-lasting effects on AMPAR subunit composition and distribution in developing neurons.
The perinatal period of brain is characterized by dynamic changes in structure and high propensity for epilepsy. Animal models have shown that alterations of AMPA receptor (AMPAR) assembly or function may be related to seizure-induced cell damage, long-lasting impairments in brain development and seizure threshold. However, effects of earlier epileptiform discharges on AMPAR composition and sub-cellular distribution remain understudied. In this study, we analyzed age-dependent variation of relative GluR1 and GluR2 protein levels in primary cultured rat cortical neurons at 7DIV, 12DIV, 17DIV and 21DIV. By inducing a single event of epileptiform activity at 6DIV, we tested the effects of early-life seizure-like insults on AMPAR subunit distribution. We found a significant increase in synaptosomal membrane GluR1 expression in magnesium-free (MGF) medium-treated neurons at each time point detected (p<0.05), while GluR2 expression increased at 7DIV, and declined at 17DIV and 21DIV respectively (p<0.05). That is, a trend of high GluR1 with much lower GluR2 expression on the surface membrane of epileptiform discharges experienced neurons over time in culture was presented. These findings in an in vitro model of early-life seizure may inform rodent models of epilepsy, as well as the cellular mechanism involved in epilepsy-associated brain dysfunction.
Jiang
Qian
Q
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
Wang
Jingmin
J
Wu
Ye
Y
Wu
Xiru
X
Qin
Jiong
J
Jiang
Yuwu
Y
D000704:Analysis of Variance; D000818:Animals; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D008274:Magnesium / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism; D013997:Time Factors
D008274:Magnesium; D018091:Receptors, AMPA; C104722:glutamate receptor ionotropic, AMPA 2