Laminar Distribution of Neurochemically-Identified Interneurons and Cellular Co-expression of Molecular Markers in Epileptic Human Cortex / 神经科学通报·英文版

Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.

Functional Investigation of a GRIN2A Variant Associated with Rolandic Epilepsy / 神经科学通报·英文版

N-methyl-D-aspartate receptors (NMDARs), a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2A (a gene encoding the NMDAR GluN2A subunit) mutations in patients with epilepsy. Phenotypes of GRIN2A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2A mutation (c.1341T>A, p.N447K) from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizure-free with a combination of valproate and lamotrigine. Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293T cells revealed that the N447K mutation increased the NMDAR current density by ~1.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg inhibition. These results indicated that N447K is a gain-of-function mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue (N447A and N447E) did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447K as a novel mutation associated with epilepsy and validated its functional consequences in vitro. Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.

Efficacy and safety of cyclophosphamide as a sequential immunotherapy drug for anti-N-methyl-D-aspartate receptor encephalitis in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of cyclophosphamide as a second-line drug in the treatment of children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.</p><p><b>METHODS</b>Six children with anti-NMDAR encephalitis, who showed poor response to steroids and intravenous immunoglobulin, were given cyclophosphamide as a second-line immunotherapy. Follow-up was performed to evaluate the efficacy and safety of cyclophosphamide.</p><p><b>RESULTS</b>After first-line immunotherapy for 1-4 weeks, the six patients had reduced psychiatric symptoms, seizures, and involuntary movements; three patients had an improved level of consciousness and were able to make simple conversations. However, all the patients still showed slow response, as well as cortical dysfunction symptoms such as aphasia, alexia, agraphia, acalculia, apraxia, and movement disorders. The six patients continued to receive cyclophosphamide as a sequential therapy. They were able to answer simple questions 7 days after treatment. Three school-aged patients were able to make simple calculation, had greatly improved reading and writing ability, and almost recovered self-care ability 2-3 weeks later. The cognitive function of the six patients was almost restored to the level before the onset of disease, and their living ability returned to normal 2-3 months later. During the treatment period, there were no adverse reactions or abnormal results of routine blood test and liver and kidney function tests.</p><p><b>CONCLUSIONS</b>Children with anti-NMDAR encephalitis should be given appropriate immunotherapy as soon as possible. Cyclophosphamide as a sequential therapy has good efficacy and safety.</p>

Antiepileptic drug trials with greater attention to daily clinical practice and special epilepsy syndromes

Most of the present antiepileptic drug trials focus on efficacy and short-term safety with limited information relevant for daily clinical practice, such as spectrum of efficacy, effective dose, titration method, drug interactions, and long-term outcome. Antiepileptic drug trials more akin to daily clinical practice should also be emphasized in future trials. There are, limited randomized control trials for certain seizure types or epilepsy syndromes, such as Lennox-Gastaut syndrome and severe myoclonic epilepsy in infancy. The author proposed self-controlled “class S” study in patients who has well-defined epilepsy syndrome with homogeneity in evolution of illness and high frequency of seizures.

Expression changes of microtubule associated protein 1B in the brain of Fmr1 knockout mice / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To explore the regulatory effect of fragile X mental retardation protein (FMRP) on the translation of microtubule associated protein 1B (MAP1B).</p><p><b>METHODS</b>The expressions of MAP1B protein and MAP1B mRNA in the brains of 1-week and 6-week old fragile X mental retardation-1 (Fmr1) knockout (KO) mice were investigated by immunohistochemistry, Western blot, and in situ hybridization, with the age-matched wild type mice (WT) as controls.</p><p><b>RESULTS</b>The mean optical density (MOD) of MAP1B was significantly decreased in each brain region in KO6W compared with WT6W, whereas in KO1W, this decrease was only found in the hippocampus and cerebellum. MAP1B in 6-week mice was much less than that in 1-week mice of the same genotype. The results of Western blot and in situ hybridization showed that MAP1B protein and MAP1B mRNA were significantly decreased in the hippocampus of both KO1W and KO6W.</p><p><b>CONCLUSION</b>The decreased MAP1B protein and MAP1B mRNA in the Fmr1 knockout mice indicate that FMRP may positively regulate the expression of MAP1B.</p>

Comparison of Behavioral and Histological Changes between Pilocarpine-Induced Temporal Epilepsy Model and Pentylenetetrazole Kindling Absence Model in Rats / 中国康复理论与实践

@#ObjectiveTo investigate and compare the behavioral changes, neuron loss of hippocampus and mossy fiber sprouting between pilocarpine-induced status epilepticus (SE) model and pentylenetetrazole (PTZ) kindling model in rats.MethodsAfter two different epilepsy models were made, Vedio was adopted to observe the behavioral changes. Nissl staining and Neo-timms' staining were separately used to observe and compare the neuron loss of hippocampus and mossy fiber sprouting in the dentate gyrus (DG) at different time points during epileptogenisis.ResultsNo recurrent spontaneous seizure, no neuron loss and no mossy fiber sprouting were found in PTZ kindling model; whereas obvious neuron loss was found in CA1, CA3 of hippocampus and hilus of DG, and mossy fiber sprouting were found in pilocarpine model in parallel with recurrent spontaneous seizures. ConclusionPTZ kindling model resembles absence epilepsy in human, while pilocarpine-induced status epilepticus model resembles chronic temporal epilepsy in human. Neuron loss and mossy fiber sprouting may play an important role in epileptogenisis. Pilocarpine-induced epilepsy model can be regarded as an ideal chronic temporal epilepsy model.

Immunohistochemical investigation of voltage-gated potassium channel-interacting protein 1 in normal rat brain and Pentylenettrazole-induced seizures / 神经科学通报·英文版

Objective To explore the possible role of voltage-gated potassium channel-interacting protein 1 (KChIP1) in the pathogenesis of epilepsy. Methods Sprague Dawley female adult rats were treated with pentylenettrazole (PTZ) to develop acute and chronic epilepsy models. The approximate coronal sections of normal and epilepsy rat brain were processed for immunohistochemistry. Double-labeling confocal microscopy was used to determine the coexistence of KChIP1 and gamma-aminobutyric acid (GABA). Results KChIP1 was expressed abundantly throughout adult rat brain. KChIP1 is highly co-localize with GABA transmitter in hippocampus and cerebral cortex. In the acute PTZ-induced convulsive rats, the number of KChIP1-postive cells was significantly increased especially in the regions of CA1 and CA3 (P < 0.05); whereas the chronic PTZ-induced convulsive rats were found no changes. The number of GABA-labeled and co-labeled neurons in the hippocampus appeared to have no significant alteration responding to the epilepsy-genesis treatments. Conclusion KChIP1 might be involved in the PTZ-induced epileptogenesis process as a regulator to neuronal excitability through influencing the properties of potassium channels. KChIP1 is preferentially expressed in GABAergic neurons, but its changes did not couple with GABA in the epileptic models.

Changes of amino acid content in hippocampus of epileptic rats treated with volatile oil of Acorus tatarinowii / 中国中药杂志

<p><b>OBJECTIVE</b>To study the changes of excitatory and inhibitory amino acid content in hippocampus of epileptic rats treated with volatile oil of A. tatarinowii, and explore the possible antiepiletic mechanism.</p><p><b>METHOD</b>The volatile oil was extracted through Supercritical-CO2 Fluid Extraction (SFE-CO2), and epileptic models were built up by kainic acid (KA) lateral ventricle injection. The content of amino acid in hippocampus of epileptic rats treated with volatile oil was calculated.</p><p><b>RESULT</b>The content of GABA increased and Glu decreased prominently (P < 0.05) after volatile oil 35 mg x kg(-1) intraperitoneal injection.</p><p><b>CONCLUSION</b>The volatile oil of A. tatarinowii can modulate the balance of excitatory and inhibitory amino acid in epileptic rats, thereby exerting its antiepileptic effect.</p>