Lethargic (lh/lh) mice, which function as an animal model of absence seizures, have spontaneous seizures that have behavioral and electrographic features and anticonvulsant sensitivity similar to those of human absence seizures. Antagonists of the gamma-aminobutyric acidB (GABAB) receptor suppressed these seizures in lethargic mice, whereas agonists of GABAB receptors exacerbated them. Furthermore, GABAB receptor binding and synaptically evoked GABAB receptor-mediated inhibition of N-methyl-D-aspartate responses were selectively increased in lh/lh mice. Therefore, enhanced GABAB receptor-mediated synaptic responses may underlie absence seizures in lh/lh mice, and GABAB receptor antagonists hold promise as anticonvulsants for absence seizures.

Expression of the immediate-early gene c-fos has been advanced as a marker of neuronal activity in the adult nervous system. We sought to test the validity of c-fos mRNA expression as a marker of neuronal activity during seizures and to elucidate specific neurotransmitter receptors whose activation was necessary for seizure-evoked c-fos mRNA expression. We correlated c-fos mRNA expression, measured with in situ hybridization, with kindled seizure-induced firing of hippocampal dentate granule cells or substantia nigra pars compacta and pars reticulata neurons. We found that the occurrence of seizure-evoked synchronous action potentials during the seizure exhibited a perfect qualitative correlation with the presence of c-fos mRNA expression in the granule cells 30 min following the seizure (Fisher's exact test, p = 0.002). However, there was no quantitative correlation between the number of seizure-induced population action potentials and the magnitude of c-fos mRNA expression in the granule cells. In the substantia nigra, where neuronal populations have previously been demonstrated to exhibit synchronous firing during kindled seizures, no induction of c-fos mRNA was detected in either pars compacta or pars reticulata. Pretreatment with antagonists of the NMDA subtype of glutamate receptor selectively and markedly decreased seizure-induced c-fos mRNA expression in the dentate granule cells, despite increasing the number of granule cell population action potentials. These findings illustrate the complexity of the relationship between c-fos induction and neuronal burst firing during kindled seizures.(ABSTRACT TRUNCATED AT 250 WORDS)

Despite growing evidence that Long noncoding RNAs (lncRNAs) can regulate gene expression and widely take part in autoimmune and inflammatory diseases, our knowledge of systemic lupus erythematosus (SLE)-related lincRNAs remains limited. In this study, we aimed to explore the contribution of the lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) to the pathogenesis of SLE. PBMCs were obtained from SLE patients and healthy donors. The expression levels of MALAT-1 were measured by quantitative PCR. Small interfering RNA (siRNA) was then used to knock down the expression of MALAT1 in order to determine the role of MALAT1 in the expression levels of IL-21 and SIRT1 signaling pathway in primary monocytes of SLE patients. Here, we found MALAT-1 expression was abnormally increased in SLE patients and predominantly expressed in human monocytes. Additionally, silencing MALAT-1 significantly reduced the expression of IL-21 in primary monocytes of SLE patients. Furthermore, MALAT-1 exerts its detrimental effects by regulating SIRT1 signaling. Our results demonstrate that MALAT-1 is the key regulatory factor in the pathogenesis of SLE and provides potentially novel target for therapeutic intervention.