Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron-glia interaction mediated by the C3-TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3-TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.
Animals ; Astrocytes/metabolism* ; Complement C3/metabolism* ; Epilepsy ; Mice ; Neurons/pathology* ; Status Epilepticus ; TRPV Cation Channels/metabolism*

Accumulating data have revealed that abnormal activity of the mTOR (mammalian target of rapamycin) pathway plays an important role in epileptogenesis triggered by various factors. We previously reported that pretreatment with perifosine, an inhibitor of Akt (also called protein kinase B), abolishes the rapamycin-induced paradoxical increase of S6 phosphorylation in a rat model induced by kainic acid (KA). Since Akt is an upstream target in the mTOR signaling pathway, we set out to determine whether perifosine has a preventive effect on epileptogenesis. Here, we explored the effect of perifosine on the model of temporal epilepsy induced by KA in rats and found that pretreatment with perifosine had no effect on the severity or duration of the KA-induced status epilepticus. However, perifosine almost completely inhibited the activation of p-Akt and p-S6 both acutely and chronically following the KA-induced status epilepticus. Perifosine pretreatment suppressed the KA-induced neuronal death and mossy fiber sprouting. The frequency of spontaneous seizures was markedly decreased in rats pretreated with perifosine. Accordingly, rats pretreated with perifosine showed mild impairment in cognitive functions. Collectively, this study provides novel evidence in a KA seizure model that perifosine may be a potential drug for use in anti-epileptogenic therapy.
Animals ; Anticonvulsants ; pharmacology ; Brain ; drug effects ; pathology ; Convulsants ; toxicity ; Disease Models, Animal ; Epilepsy, Temporal Lobe ; chemically induced ; pathology ; Kainic Acid ; toxicity ; Male ; Neurons ; drug effects ; pathology ; Phosphorylcholine ; analogs & derivatives ; pharmacology ; Protein Kinase Inhibitors ; pharmacology ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; chemically induced ; pathology

Temporal lobe epilepsy (TLE) is a common and severe neurological disorder which is often intractable. It can not only damage the normal structure and function of hippocampus, but also affect the neurogenesis in dentate gyrus (DG). It is well documented from researches on the animal models of TLE that after a latent period of several days, prolonged seizure activity leads to a dramatic increase in mitotic activity in the hippocampal DG. However, cell proliferation returns to baseline levels within 3-4 weeks after status epilepticus (SE). Meanwhile, there are two major abnormalities of DG neurogenesis, including the formation of hilar basal dendrites and the ectopic migration of newborn granule cells into the polymorphic cell layer, which may affect epileptogenesis and seizure onset. However, the specific contribution of these abnormalities to seizures is still unknown. In other words, whether they are anti-epileptic or pro-epileptic is still under heated discussion. This article systematically reviews current knowledge on neurogenesis and epilepsy based on the results of studies in recent years and discusses the possible roles of neurogenesis in epileptogenesis and pathologic mechanisms, so as to provide information for the potential application of neurogenesis as a new clinical therapeutic target for temporal lobe epilepsy.
Animals ; Brain ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Dendrites ; pathology ; Dentate Gyrus ; growth & development ; pathology ; Epilepsy, Temporal Lobe ; etiology ; pathology ; physiopathology ; Hippocampus ; growth & development ; pathology ; Humans ; Mitosis ; physiology ; Neurogenesis ; physiology ; Neurons ; pathology ; Seizures ; etiology ; physiopathology ; Status Epilepticus ; physiopathology

Adolescent ; Adult ; Anesthetics, Intravenous ; Electroencephalography ; Female ; Humans ; Hypothermia, Induced ; methods ; Male ; Prospective Studies ; Status Epilepticus ; pathology ; therapy ; Young Adult

2-Aminoadipic Acid ; analogs & derivatives ; analysis ; Aldehyde Dehydrogenase ; genetics ; Anticonvulsants ; therapeutic use ; Biomarkers ; analysis ; Brain ; pathology ; DNA Mutational Analysis ; Electroencephalography ; Epilepsy ; diagnosis ; drug therapy ; genetics ; Genetic Association Studies ; Humans ; Infant ; Infant, Newborn ; Magnetic Resonance Imaging ; Mutation, Missense ; Prognosis ; Pyridoxine ; therapeutic use ; Seizures ; diagnosis ; drug therapy ; genetics ; Status Epilepticus ; diagnosis ; drug therapy ; genetics

Anticonvulsants ; therapeutic use ; Brain ; pathology ; physiopathology ; Brain Waves ; physiology ; Child ; Electroencephalography ; Humans ; Landau-Kleffner Syndrome ; physiopathology ; Sleep ; physiology ; Sleep Stages ; physiology ; Status Epilepticus ; epidemiology ; etiology ; physiopathology ; therapy

We report on a 55-year-old man with alcoholic liver cirrhosis who presented with status epilepticus. Laboratory analysis showed markedly elevated blood ammonia. Brain magnetic resonance imaging (MRI) showed widespread cortical signal changes with restricted diffusion, involving both temporo-fronto-parietal cortex, while the perirolandic regions and occipital cortex were uniquely spared. A follow-up brain MRI demonstrated diffuse cortical atrophy with increased signals on T1-weighted images in both the basal ganglia and temporal lobe cortex, representing cortical laminar necrosis. We suggest that the brain lesions, in our case, represent a consequence of toxic effect of ammonia.
Ammonia/blood ; Atrophy/pathology ; Brain Diseases/blood/*diagnosis/*etiology ; Hepatic Encephalopathy/*complications ; Humans ; Liver Cirrhosis, Alcoholic/*complications ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Necrosis/pathology ; Status Epilepticus/pathology

OBJECTIVETo investigate the characteristics of microglial activation of hippocampus in experimental epileptic rats.

METHODSMorphological changes and proliferation of OX-42 positive cells were compared at different time points after status of epilepticus (SE) in lithium-pilocarpine induced epileptic rats.

RESULTSOX-42 positive cells were activated after SE, which increased to a peak at 3-7 d and in a relatively stable state at 7-14 d; then gradually decreased after 14d and returned to slightly higher level than previously at 21 d.

CONCLUSIONInflammatory injury, microglial activation and cell proliferation are closely related after seizures, microglial activation may be an important mechanism in the inflammatory injury of epilepsy.

Animals ; Cell Proliferation ; Disease Models, Animal ; Hippocampus ; cytology ; pathology ; Male ; Microglia ; pathology ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; pathology

OBJECTIVETo study the possible protection of edaravone on neurons of the hippocampus after status convulsion (SC) and its effects on the expression of interleukin-1beta (IL-lbeta) in juvenile rats.

METHODSOne hundred and ninety-five juvenile male Sprague-Dawley rats were randomly divided into three groups: SC, edaravone pretreatment and normal saline control (control group). Each group was subdivided into five groups sacrificed at 4, 12, 24, 48 and 72 hrs after SC induction. SC model was prepared using lithium-pilocarpine. The edaravone pretreatment group received edaravone by intraperitoneal injection once daily three days before convulsion induction. Histopathologic changes in the hippocampus were viewed under a light microscope and an electron microscope. Expression of apoptosis cells was observed by TdT-mediated dUTP nick end labeling (TUNEL). Expression of IL-lbeta protein was determined by immunohistochemistry.

RESULTSUnder the electron microscrope, a small quantity of neurons showed karyopycnosis and endocytoplasmic reticulum (ER) expanded remarkably 24 hrs after SC induction; at 48 hrs the ER expanding was alleviated somewhat but mitochomdria swelling was more severe. The edaravone pretreatment group showed less severe neuronal changes compared with the SC group under the microscopes. The TUNEL positive cells in the hippocampus of the SC group were significantly more than those of the control group 12 hrs, and peaked at 48 hrs after SC induction. The edaravone pretreatment group showed decreased TUNEL positive cells in the hippocampus compared with the SC group, although the positive cells were more than those in the control group between 12 and 48 hrs after SC induction. The immunohistochemistry assay demonstrated that the expression of IL-lbeta in the hippocampus of the SC group increased significantly compared with that of the control group 12, 24, 48 and 72 hrs after SC induction. Edaravone pretreatment resulted in a significantly decreased IL-lbeta expression in the hippocampus as compared with the SC group.

CONCLUSIONSEdaravone pretreatment may decrease the IL-1beta expression and neuronal apoptosis in the hippocampus. This suggests that edaravone may have protective effects against the hippocampal damage caused by SC.

Animals ; Antipyrine ; analogs & derivatives ; pharmacology ; Hippocampus ; chemistry ; drug effects ; pathology ; ultrastructure ; Immunohistochemistry ; In Situ Nick-End Labeling ; Interleukin-1beta ; analysis ; Male ; Neurons ; drug effects ; Neuroprotective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; drug therapy ; metabolism ; pathology

OBJECTIVETo investigate the expression of the key marker of endoplasmic reticulum stress (ERS) IRE1 mRNA and neuronal apoptosis in the rat hippocampus after status convulsivus (SC), and the intervention effects of edaravone, a novel free radical scavenger.

METHODSSprague-Dawley (SD) rats aged 19-21 days were randomly assigned to three groups: normal control, SC and edaravone-treated SC. SC was induced in the later two groups. The two groups were subdivided into 5 groups sacrificed at 4, 12, 24, 48, and 72 hrs after SC induction. IRE1 mRNA expression in the hippocampus was detected by RT-PCR. Neuronal apoptosis was observed by TdT-mediated dUTP nick end labeling (TUNEL). The ultramicrostructural changes of neuron were observed by electron microscopy.

RESULTSIRE1 mRNA expression was obviously up-regulated 4 and 12 hrs after SC compared with the normal control group (P<0.01). IRE1 mRNA expression in the edaravone-treated SC group was notably higher than the untreated SC group 4, 12 and 24 hrs after SC and the normal control group (P<0.01). TUNEL positive cells in the hippocampus in the untreated SC group were significantly more than those in the normal control group (P<0.01). The number of TUNEL positive cells increased with the prolonged convulsion time. TUNEL positive cells in the edaravone-treated SC group were significantly reduced compared with those in the untreated SC group 12, 24, 48 and 72 hrs after SC (P<0.05 or P<0.01), but remained higher than the normal control group (P<0.05 or P<0.01). The peri-nucleus cell organ injuries were observed 4 hrs after SC and karyopycnosis and cytoplasm condensation were observed 12 hrs after SC in the SC and the edaravone-treated SC groups. The edaravone-treated SC group demonstrated less severe apoptosis than the untreated SC group.

CONCLUSIONSEdaravone may have neuroprotections against SC by an up-regulation of IRE1 expression. It might serve as an effective agent for reducing ERS in vivo.

Animals ; Antipyrine ; analogs & derivatives ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Disease Models, Animal ; Hippocampus ; drug effects ; metabolism ; ultrastructure ; In Situ Nick-End Labeling ; Male ; Membrane Proteins ; genetics ; Neurons ; drug effects ; ultrastructure ; Protein-Serine-Threonine Kinases ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; drug therapy ; metabolism ; pathology