Encefalitis autoinmune posherpética. Caso clínico pediátrico / Autoimmune post-herpes simplex encephalitis. A pediatric clinical case report

La encefalitis por virus herpes simple (VHS) es una causa frecuente de encefalitis grave y potencialmente fatal. La encefalitis autoinmune posherpética (EAPH) afecta a un porcentaje de los pacientes que han presentado encefalitis herpética (EH) y se caracteriza por la aparición de nuevos síntomas neurológico/psiquiátricos, y/o por el empeoramiento de los déficits adquiridos durante la infección viral dentro de un lapso temporal predecible. Se produce por un mecanismo no relacionado con el VHS, sino por fenómenos autoinmunes, y es susceptible de tratamiento con inmunomoduladores. Se presenta el caso de un varón de 5 años de edad con EAPH que requirió tratamiento inmunomodulador, de primera y segunda línea, con buena evolución y remisión de los síntomas.

Herpes simplex virus (HSV) encephalitis is a common cause of severe and potentially fatal encephalitis. Autoimmune post-herpes simplex encephalitis (AIPHSE) affects a percentage of patients who developed herpes simplex encephalitis (HSE) and is characterized by the onset of new neurological/psychiatric symptoms and/or worsening of deficits acquired during the herpes infection within a predictable time frame. It is caused by a mechanism not related to HSV, but by autoimmune conditions, and is susceptible to treatment with immunomodulators. Here we describe the case of a 5-year-old boy with AIPHSE who required first- and second-line immunomodulatory treatment, with an adequate course and remission of symptoms.

Secuelas cognitivas en encefalitis inmunomediadas: cohorte de pacientes en Argentina / Cognitive sequelae in immunomediated encephalitis: cohort of patients in Argentina

Resumen Introducción: Las encefalitis inmunomediadas son un desorden neurológico de origen autoinmune. Actual mente es escasa la descripción de las secuelas cognitivas crónicas. El objetivo del presente trabajo fue caracterizar la secuela cognitiva de diferentes tipos de encefalitis inmunomediadas en una cohorte de un centro único de Argentina. Métodos: Estudio prospectivo, observacional, trans versal, de pacientes en seguimiento en un hospital de la Ciudad de Buenos Aires, con diagnóstico de encefalitis inmunomediada probable y definitiva. Se evaluaron variables epidemiológicas, clínicas, paraclínicas y tra tamiento. Se determinó la secuela cognitiva a través de una evaluación neurocognitiva realizada a partir del año de la presentación clínica. Resultados: Fueron incluidos 15 pacientes, todos con resultado disminuido en al menos un test. La memoria fue el dominio más afectado. Aquellos que se encon traban bajo tratamiento inmunosupresor al momento de evaluarse presentaron menores resultados en el aprendizaje seriado (media -2.94; desvío estándar 1.54) versus los que se encontraban sin tratamiento (media -1.18; desvío estándar 1.40; p = 0.05) y en la prueba de reconocimiento (media -10.34; desvío estándar 8.02) ver sus sin tratamiento (media -1.39; desvío estándar 2.21; p = 0.003). Los pacientes con estatus epiléptico tuvieron resultados deficitarios en la prueba de reconocimiento (media -7.2; desvío estándar 7.91) en comparación a los que no lo tenían (media -1.47; desvío estándar 2.34; p = 0.05). Conclusión: Nuestros resultados demuestran que, a pesar del curso monofásico de la enfermedad, todos los pacientes presentan daño cognitivo persistente más allá del año del inicio del cuadro. Estudios prospectivos de mayor envergadura serían necesarios para confirmar nuestros hallazgos.

Abstract Introduction: Autoimmune encephalitis represents a group of immune-mediated neurological disorders. At present, the description of the chronic cognitive sequela is scarce. The objective of this study was to characterize the cognitive after effects of different types of autoimmune encephalitis in a cohort from a single center in Argentina. Methods: Prospective, observational, cross-sectional study of patients under follow-up at a hospital in Buenos Aires city, with a diagnosis of probable and definitive immune-mediated encephalitis. Epidemiological, clini cal, paraclinical and treatment related variables were evaluated. Cognitive sequela was determined through a neurocognitive evaluation performed at least a year after the clinical presentation. Results: Fifteen patients were included. All had di minished results in at least one test. Memory was the most affected domain. Patients who were under im munosuppressive treatment at the time of evaluation presented lower results in serial learning (mean -2.94; standard deviation 1.54) versus those who weren't under treatment (mean -1.18; standard deviation 1.40; p = 0.05). The same pattern was observed on the recognition test of treatment group (mean -10.34; standard deviation 8.02) versus treatment-free group (mean -1.39; standard deviation 2.21; p =0.003). Patients with status epilepticus had poorer results in the recognition test (mean -7.2; standard deviation 7.91) compared to those without it (mean -1.47; standard deviation 2.34; p = 0.05). Conclusion: Our results show that, despite the mo nophasic course of this disease, all patients had persis tent cognitive damage beyond the year of onset. Larger prospective studies are required to confirm our findings.

Regulación del calcio por SERC-A antes de la enfermedad de Alzheimer y durante la misma / Calcium regulation by SERC-A before and during Alzheimer disease

Hay muchos factores implicados en la incidencia de la enfermedad de Alzheimer que, en combinación, terminan por impedir o dificultar las funciones neuronales normales. Actualmente, poco se conoce sobre la regulación del calcio, antes de la enfermedad y durante la misma. La inestabilidad interna de los niveles de calcio se asocia a un mayor riesgo vascular, condición prevalente en un gran número de individuos ya comprometidos por la enfermedad de Alzheimer. Esta revisión proporciona una reevaluación de los mecanismos moleculares de la ATPasa dependiente de Ca2+ del retículo sarcoendoplásmico (SERC-A) en la enfermedad y analiza los aspectos más destacados de la función de los canales de calcio dependientes de voltaje; de esta manera, se podrán abrir nuevas alternativas de tratamiento. Estos mecanismos de regulación son clínicamente relevantes, ya que se ha implicado la función irregular de SERC-A en diversas alteraciones de la función cerebral.

There are many factors involved in the incidence of Alzheimer's disease that, in combination, impede or hinder normal neuronal functions. Little is currently known about calcium regulation before and during the disease. Internal instability of calcium levels is associated with increased vascular risk, a prevalent condition in a high number of individuals already compromised by Alzheimer's disease. This review provides a reevaluation of the molecular mechanism of the sarcoendoplasmic reticulum calcium ATPase (SERC-A) in the disease and discusses salient aspects of voltage-gated calcium channel function; in these way new alternatives could be open for its treatment. These regulation mechanisms are clinically relevant since the irregular functions of SERC+A has been implicated in pathologies of brain function.

Recent research on cytokines associated with anti-N-methyl-D-aspartate receptor encephalitis / 中国当代儿科杂志

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune inflammatory disease of the central nervous system, and little is known about its immune mechanism at present. There is a lack of disease-related biomarkers in cerebrospinal fluid except anti-NMDAR antibody, which leads to delayed diagnosis and treatment in some patients. Therefore, there has been an increasing number of studies on related cytokines in recent years to assess whether they can be used as new biomarkers for evaluating disease conditions and assisting diagnosis and treatment. Current studies have shown that some cytokines may be associated with the progression of anti-NMDAR encephalitis, and this article reviews the research advances in such cytokines associated with anti-NMDAR encephalitis.

Exploring the effect of Tuina on the dendritic structure of spinal cord dorsal horn in rats with lumbar disc herniation based on NR2B/PSD-95 pathway / 针灸推拿医学（英文版）

Objective: To investigate the analgesic mechanism of Tuina (Chinese therapeutic massage) by observing the effect of the N-methyl-D-aspartate receptor subunit 2B (NR2B)/postsynaptic density-95 (PSD-95) pathway on the dendritic structure of spinal cord dorsal horn in rats with lumbar disc herniation. Methods: Fifty Sprague-Dawley rats were randomly divided into a blank group, a model group, a Tuina group, a blocker agent group, and a blocker agent + Tuina group. The sciatic nerve chronic constriction injury (CCI) model was prepared by the sciatic nerve ligation method. From the 4th day after modeling, rats in the Tuina group and the blocker agent + Tuina group were subject to daily Tuina intervention, and those in the blocker agent group and the blocker agent + Tuina group were daily intrathecally injected with NR2B blocker agent (MK-801). The spontaneous pain score was used to observe the pain behavior of all rats. The expression levels of NR2B and downstream PSD-95 were measured by immunohistochemistry, and the dendritic structure changes were observed by Golgi staining for rat spinal cord dorsal horn after 14 d of continuous intervention. Results: Compared with the blank group, the degree of rat spontaneous pain after CCI was elevated in both the model and the Tuina groups (P<0.01) and was reduced in the Tuina group after the Tuina intervention compared with the model group (P<0.05). Compared with the model group, the rat spontaneous pain level after blocking NR2B was reduced in both the blocker agent group and the blocker agent + Tuina group (P<0.05). The NR2B and PSD-95 protein levels were significantly higher in the model group compared with the blank group (P<0.01); the total number of dendritic branches was increased (P<0.01), and the total dendritic length became longer (P<0.01) in the spinal cord dorsal horn. The rat NR2B and PSD-95 protein levels were significantly decreased in the Tuina group compared with the model group (P<0.01); the total dendritic branch number was reduced (P<0.01) and the total length was shortened (P<0.01) in the spinal cord dorsal horn. After blocking NR2B, the expression levels of NR2B and downstream PSD-95 protein were significantly lower in both the blocker agent group and the blocker agent + Tuina group compared to the model group (P<0.01). The total branch number was significantly reduced (P<0.01), and the total length was significantly shortened (P<0.01) of the dendrites in the spinal cord dorsal horn. Conclusion: Tuina may exert an analgesic effect by remodeling the dendritic structure in the spinal cord dorsal horn in rats with lumbar disc herniation, and its mechanism may be related to the inhibition of NR2B/PSD-95 signaling pathway.

Advances in relapse risk factors of anti-N-methyl-D-aspartate receptor encephalitis / 中华神经科杂志

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis mediated by anti-NMDAR antibody. Current studies have found that most patients with anti-NMDAR encephalitis have a good prognosis after immunotherapy and tumor therapy, but there are still 4.5%-36.4% patients with relapse. It is important to identify the risk factors for the prevention of relapse. This article aims to review the relapse risk factors of NMDAR encephalitis in order to provide help for the prevention of relapse.

Abnormal topology of cortical thickness covariance network and altered functional connectivity in patients with anti-N-methyl-D-aspartate receptor encephalitis / 中华行为医学与脑科学杂志

Objective:To explore the changes in topological attributes of structural covariance network based on cortical thickness and the brain functional activities in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis by graph theory and functional connectivity (FC) analyses, and to investigate whether these changes were correlated to cognitive impairment.Methods:A total of 33 patients with anti-NMDAR encephalitis from Department of Neurology of the First Affiliated Hospital of Guangxi Medical University(patient group) and 35 healthy controls(control group) with matched gender, age, and education were included from July 2018 to November 2021.All subjects received cognitive function assessments, structural and functional magnetic resonance imaging scans.Structural covariance networks were constructed in the two groups based on cortical thickness values and topological characteristics of networks were computed.A non-parametric permutation test which repeated 1 000 times was used to compare the characteristics of the networks between the two groups.Brain regions with abnormal topology were defined as region of interest(ROI), and FC values in global brain level were calculated.SPM 12 and RESTplus were used to identify the brain regions with significant differences in FC values between the two groups.Finally, Spearman correlation analysis between FC values of significant brain regions and cognitive scores were performed by SPSS 24.0.Results:The cognitive score of patients with anti-NMDAR encephalitis (27.0(23.5, 28.0)) was lower than that in control group(29.0(27.0, 30.0)) ( Z=-3.029, P=0.002). Graph theory analysis found that the patients showed significantly increased clustering coefficients ( P=0.004) and decreased global efficiency ( P=0.004) compared with healthy controls.Moreover, the nodal efficiency of left ventral posterior cingulate cortex (vPCC) and right dorsal posterior cingulate cortex (dPCC), as well as the nodal degree centrality of left vPCC and left polar planum of superior temporal gyrus (ppSTG) in patient group were significantly decreased ( P<0.05, FDR corrected) compared with control group.FC analysis showed the increased FC values between left vPCC and posterior cerebellum (MNI: x=6, y=-66, z=-21), as well as between left ppSTG and anterior cerebellum (MNI: x=6, y=-54, z=-12) (GRF corrected, voxel level P<0.001, cluster level P<0.05) in patient grooup.The FC values between left vPCC and posterior cerebellum were negatively correlated with the cognitive scores ( r=-0.403, P=0.020). Conclusion:Patients with anti-NMDAR encephalitis show abnormal topology of structural covariance network based on cortical thickness and altered FC values, some of which are correlated to cognition and may be the underlying neural mechanism of cognitive impairment in patients with anti-NMDAR encephalitis.

Encefalitis inmunomediada en un niño con antecedente de infección por SARS-CoV-2 n / Immune-mediated encephalitis in a child with a history of SARS-CoV-2 infectio

Las encefalitis son cuadros clínicos frecuentes en la edad pediátrica. Pueden dividirse en aquellas causadas por la infección del sistema nervioso central y en las de etiología inmunomediada (algunas de las cuales pueden ser para- o posinfecciosas). En marzo de 2020 la Organización Mundial de la Salud declaró la pandemia por el coronavirus de tipo 2 del síndrome respiratorio agudo grave (SARS-CoV-2, por su sigla en inglés). Los reportes pediátricos de enfermedad por dicho agente describen una amplia gama de manifestaciones clínicas: compromiso respiratorio, gastrointestinal, síntomas neurológicos, entre otros; y el síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-C). Describimos el caso de un niño de 2 años con diagnóstico de encefalitis por anticuerpos antirreceptor N-metil-d-aspartato (anti-NMDAR), en quien se comprobó, mediante serología, una infección reciente por SARS-CoV-2. La presencia de marcadores serológicos positivos para SARS-CoV-2 en un paciente que presentó encefalitis por anticuerpos anti-NMDAR podría interpretarse como una asociación temporal, estableciéndose la posibilidad de que el virus haya actuado como gatillo de una enfermedad autoinmunitaria.

Encephalitis are frequent clinical pictures in pediatric age. They can be divided into those caused by infection of the central nervous system and those of immune-mediated etiology (some of which may be para- or post-infectious). In March 2020, the WHO declared a SARS-CoV-2 pandemic. Pediatric reports of disease caused by this agent describe a wide range of clinical manifestations: respiratory and gastrointestinal compromise, neurological symptoms, among others; and a multisystemic inflammatory syndrome in children associated with COVID-19 (MIS-C).We describe the case of a 2-year-old boy with a diagnosis of anti-NMDAR antibody encephalitis, in whom a recent SARSCoV-2 infection was serologically proven. The presence of positive serological markers for SARS-CoV-2 in a patient who presented encephalitis due to anti-NMDAR antibodies could be interpreted as a temporal association; establishing the possibility that the virus has acted as a trigger for an autoimmune disease

Manejo de Encefalitis anti-NMDAR con Rituximab: Reporte de caso en un Hospital Público de Lima, Perú

Introducción: La encefalitis autoinmune comprende un amplio espectro de desórdenes inmunológicos, entre ellos el anti-NMDAR es el más frecuente. El manejo de esta patología es complejo debido a múltiples circunstancias. Reporte de caso: Mujer de 19 años que inicia cuadro subagudo con trastorno conductual y neurológico asociado: Alucinaciones, heteroagresividad, mutismo acinético, crisis epilépticas, discinesias orofaciales, fiebre y arritmia cardiaca transitoria reportada. La resonancia fue normal, el EEG registró ondas delta brush, Los estudios de LCR y séricos fueron negativos para causas secundarias. Se inició tratamiento con Aciclovir, medicamento anticrisis y psicofármacos, posteriormente se inicia metilprednisolona con inmunoglobulina sin respuesta satisfactoria. Inicia tratamiento con Rituximab presentando una respuesta favorable. El panel en LCR fue positivo a NMDA. Se indica control con desescalamiento progresivo de medicamentos anticrisis y psicofármacos. Conclusión: Es importante reconocer tempranamente las manifestaciones clínicas de esta entidad para así realizar un manejo oportuno que podría mejorar el pronóstico.

Introduction: Autoimmune encephalitis comprises a wide spectrum of immunological disorders, among them anti-NMDAR is the most frequent. The management of this pathology is complex due to multiple circumstances. Case report: A 19-year-old woman who started a subacute clinical picture with associated behavioral and neurological disorder: hallucinations, heteroaggressiveness, akinetic mutism, epileptic seizures, orofacial dyskinesias, fever and reported transient cardiac arrhythmia. MRI was normal, EEG recorded delta brush waves, CSF and serum studies were negative for secondary causes. Treatment was started with Acyclovir, an anti-crisis drug, and psychotropic drugs, later methylprednisolone with immunoglobulin was started without a satisfactory response. She starts treatment with Rituximab presenting a favorable response. The CSF panel was positive for NMDA. Control with progressive de-escalation of anti-crisis medications and psychotropic drugs is indicated. Conclusion: It is important to recognize early the clinical manifestations of this entity in order to carry out timely management that could improve the prognosis.

Encefalitis anti-receptor NMDA: un diagnóstico a considerar / Anti- receptor NMDA encephalitis, a diagnosis to consider

Resumen Las encefalitis son trastornos inflamatorios cerebrales, secundarias a diferentes procesos patológicos que incluyen causas infecciosas y autoinmunes. En los últimos años se han estudiado los procesos autoinmunes involucrados, con una creciente identificación de casos donde presenta una amplia variedad de síntomas neurológicos y psiquiátricos que suelen dificultar el diagnóstico oportuno. Por tanto, esta es una revisión narrativa que describe los principales aspectos de la encefalitis por anticuerpos contra el receptor de N-metil-D-aspartato (NMDAR), su patogénesis (mecanismo que comparte con los trastornos psicóticos), diagnóstico y presentación clínica; aspectos que destacan la importancia de una evaluación exhaustiva de las manifestaciones psiquiátricas en el ámbito clínico.

Abstract Encephalitis are inflammatory brain disorders that are secondary to different pathological processes that include infectious and autoimmune causes. In recent years, the autoimmune processes involved have been studied with an increment in the identification of cases that present a wide variety of neurological and psychiatric symptoms, which often make their timely diagnosis difficult. This is a narrative review that describes the main aspects of encephalitis caused by antibodies against the N-methyl-D-aspartate receptor (NMDAR), its pathogenesis (mechanism shared with psychotic disorders), diagnosis, and clinical presentation; these are aspects that highlight the importance of a thorough evaluation of psychiatric manifestations in the clinical setting.

A critical review and update on autoimmune encephalitis: understanding the alphabet soup / Revisão crítica e atualizações em encefalites autoimunes: entendendo a sopa de letrinhas

ABSTRACT Autoimmune encephalitis (AE) comprises a group of diseases mediated by antibodies against neuronal cell surface or synaptic antigens, such as ion channels or neurotransmitter receptors. New clinical syndromes and their associated antibodies were and are still being characterized over the last two decades. The fact that their main clinical features are interdisciplinary, - encompassing neuropsychiatric symptoms, cognitive dysfunction, epileptic seizures, movement and sleep disorders - has led to a surge of interest in this field. Some of these diseases present with a well-defined syndrome, being recognizable on clinical grounds. Correct diagnosis is important since AE are potentially treatable diseases, despite their severity. On the other hand, an increasing number of neuronal antibodies being described casts doubt upon the way we should utilize antibody testing and interpret results. In this article we review, summarize and update the current knowledge on antibody mediated encephalitis.

RESUMO As encefalites autoimunes compreendem um grupo de doenças mediadas por anticorpos contra antígenos de superfície neuronal ou sinapse, como canais iônicos ou receptores de neurotransmissores. Novas síndromes clínicas e os anticorpos a elas associados foram e ainda estão sendo caracterizados ao longo das últimas duas décadas. Dado que suas principais características clínicas são interdisciplinares, isto é, incluem -se sintomas neuropisquiátricos, disfunção cognitiva, crises epilépticas, distúrbio do movimento e do sono, há uma grande onda de interesse sobre esse campo de conhecimento. Algumas dessas doenças apresentam-se com uma síndrome bem definida, sendo possível reconhecê-las clinicamente. Diagnosticá-las corretamente é importante uma vez que se trata de doenças potencialmente tratáveis apesar da gravidade que lhes é característica. Por outro lado, o número crescente de anticorpos sendo descritos causam dúvida frequente sobre qual o melhor teste a solicitar e como interpretá-los. Nós aqui apresentamos uma revisão atualização resumida do conhecimento atual sobre as encefalites mediadas por anticorpos.

Encefalitis por anticuerpos contra el receptor N-metil-D-aspartato secundaria a teratoma ovárico en una paciente pediátrica / Encephalitis due to antibodies against the N-methyl-D-aspartate receptor secondary to ovarian teratoma in a pediatric patient

La encefalitis por anticuerpos contra el receptor N-metilD-aspartato es un proceso inmunomediado en el que autoanticuerpos se dirigen contra la subunidad GluN1 del receptor de glutamato del sistema nervioso central. Se caracteriza por la aparición aguda o subaguda de síntomas psiquiátricos, como confusión, pérdida de la memoria a corto plazo, cambios de conducta, catatonía, seguidos por manifestaciones neurológicas, tales como convulsiones, alteraciones del movimiento, disfunciones autonómicas, coma y depresión respiratoria. Es grave y potencialmente mortal. Su asociación con teratoma de ovario como síndrome paraneoplásico fue descrita en mujeres jóvenes. En la población pediátrica, es mucho menos frecuente y se reporta en comunicaciones de 1 o 2 pacientes y en series de pocos casos. Se presenta una paciente de 13 años con encefalitis paraneoplásica por anticuerpos contra el receptor N-metil-Daspartato, secundaria a un teratoma ovárico maduro.

The encephalitis due to antibodies against the N-methylD-aspartate receptor is a process immune-mediated in which antibodies are directed against the GluN1 subunit of the glutamate receptor in the central nervous system. It is characterized by an acute or subacute onset of psychiatric symptoms such as confusion, short-term memory loss, behavioral changes, catatonia followed by neurological manifestations such as seizures, movement disturbances, autonomic dysfunctions, coma, and respiratory depression. It is serious and life threatening. Its association with ovarian teratoma as a paraneoplastic syndrome was described in youngwomen. In the pediatric population it is much less frequent and is reported in publications of one or two patients and in series of few cases. We present a 13-year-old patient with encephalitis paraneoplastic due to antibodies against the N-methyl-Daspartate receptor, secondary to a mature ovarian teratoma.

More than teen angst: A case of ovarian teratoma presenting as anti-N-methyl-d-aspartate receptor encephalitis / Philippine Journal of Obstetrics and Gynecology

@#A 17‑year‑old nulligravid presented with labile mood, insomnia, and hyper‑productive speech for 2 days, which progressed to seizures. Cerebrospinal fluid was positive for anti‑N‑methyl‑d‑aspartate (NMDA) receptor antibodies. Despite immunotherapy and seizure prophylaxis, she had status epilepticus and rapid decrease in sensorium. She was placed on ventilatory support and was admitted in the intensive care unit. On the 44th hospital day, an incidental finding of an ovarian teratoma was seen on abdominal computed tomography scan. She underwent right salpingo‑oophorectomy, which revealed an immature teratoma. The absence of an intensive care admission and prompt surgery and immunotherapy are known predictors of good outcome in anti‑NMDA receptor (NMDAR) encephalitis, with improvement seen in 80% of patients. Because most ovarian teratomas are only diagnosed as an incidental finding, anti‑NMDAR encephalitis with a concurrent ovarian teratoma should be suspected in young females presenting with sudden‑onset neuropsychiatric symptoms, to provide the timely intervention necessary for a good prognosis.

Effects of subchronic exposure to benzoɑpyrene on memory function and mRNA expressions of NMDA receptors in different brain regions in rats / 环境与职业医学

Background The altered expressions of hippocampal N-methyl-D-aspartate (NMDA) receptors induced by benzo[ɑ]pyrene (BaP) causes short-term spatial learning and memory impairment in humans and animals, but whether BaP causes alterations of NMDA receptor subunits in other brain regions and the associated neurotoxic mechanism is still essentially unknown. Objective To observe the mRNA expressions of NR1, NR2A, and NR2B of NMDA receptor subunits in different brain regions in SD rat model with subchronic exposure to BaP, and to provide a basis for in-depth study of the mechanism of BaP-induced neurotoxicity. Methods Forty male SD rats were selected and randomly divided into a control group and 1.00, 2.50, and 6.25 mg·kg−1 BaP exposure groups with 10 rats in each group. The exposure rats received intraperitoneal injection of BaP every other day for 90 d.The average latency to platform, the average total distance, and the duration spent in previous quadrant were measured by the Morris Water Maze. Real-time fluorescence quantitative PCR was used to detect the mRNA expressions of NR1, NR2A, and NR2B in hippocampus, cortex, cerebellum, and striatum of rats. Results The average latency to platform and the average total distance in the 2.50 and 6.25 mg·kg−1 BaP groups were significantly prolonged compared with the control group (P<0.05), and the duration that rats spent in previous quadrant in the 6.25 mg·kg−1 BaP group was significantly shortened (P<0.05). Compared with the control group, the mRNA expressions of NR1 and NR2B in the hippocampus in the 2.50 and 6.25 mg·kg−1 BaP groups were significantly reduced (P<0.05), and the NR2A mRNA expression in the hippocampus in the 6.25 mg·kg−1 BaP group was significantly reduced (P<0.05); the mRNA expressions of NR1 and NR2B in the cortical tissue in the 6.25 mg·kg−1 BaP group were significantly reduced (P<0.05), and the mRNA expression of NR2A in the cortical tissue in the 1.00 mg·kg−1 BaP group was reduced; the mRNA expression of NR2B in the cerebellar tissue in the 6.25 mg·kg−1 BaP group was significantly reduced (P<0.05); there were no differences in the mRNA expressions of NMDA receptor subunits in the striatum tissue (P>0.05). Conclusion Subchronic BaP exposure can cause short-term spatial learning and memory impairment in rats, which may be related to the down-regulation of mRNA expressions of NR1, NR2A, and NR2B in hippocampus, changes of mRNA expressions of NR1, NR2A, and NR2B in cortical area, and the down-regulation of NR2B mRNA expression in cerebellum.

Transcranial direct current stimulation for the relief of neuropathic pain in rats and the underlying mechanism / 中华物理医学与康复杂志

Objective:To observe any therapeutic effect of repeated transcranial direct current stimulation (tDCS) on rats modeling neuropathic pain and explore possible mechanisms.Methods:Forty adult male Sprague-Dawley rats were randomly divided into a normal group ( n=10), a sham operation group ( n=10), a treatment group ( n=10) and a sham treatment group ( n=10). A model of chronic constriction injury of the sciatic nerve was established in the latter two groups. Fourteen days after the modeling, the treatment group was given tDCS for 8 consecutive days, while the sham treatment group received sham stimulation, and the other 2 groups did not receive any intervention. Von Frey and hotplate tests were used to test the rats′ pain thresholds 1 day before, as well as 14 and 22 days after the surgery (i.e., 8 days after the end of the treatment). Spinal cord tissue samples were taken to detect the protein expressions of N-methyl-D-aspartic acid receptor 2B, gamma-aminobutyric acid receptor types A (GABA a-R) and B (GABA b-R) using western blotting. Results:On the 14th day after the operation the average 50% MWT and WTL values of the sham treatment and treatment groups had decreased significantly compared with the sham operation group. By the 22nd day the average 50% MWT and WTL values of the treatment group were significantly higher than those of the sham treatment group, but there was no significant change in the treatment group′s average WTL between the 21st and 22nd days. On the 22nd day after the operation the average NR2B-NMDA-R level of the sham treatment group were significantly higher than that of the sham operation group, while the average GABA a-R and GABA b-R levels were significantly lower. At the same time point the treatment group′s average NR2B-NMDA-R level had decreased significantly compared to the sham treatment group, while the average GABA a-R level had increased significantly. There was no significant difference in average GABA b-R level between the treatment group and the sham treatment group at that point. On the 22nd day there was also no significant difference in the average NR2B-NMDA-R level between the treatment group and the sham operation group. Conclusions:Repeated tDCS can effectively relieve neuropathic pain. The relief of hyperalgesia is more significant than that of mechanical allodynia. A possible mechanism may be the down-regulation of spinal NR2B-NMDA-R to normal levels and modest up-regulation of GABA a-R.

Recent advance in experimental animal models of anti-N-methyl-D-aspartate receptor encephalitis / 中华神经科杂志

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis mediated by anti-NMDAR antibody. At present, the pathogenesis of the disease is not completely clear, and reliable animal models are of great significance for the study of its pathogenesis and pathophysiological process. The authors reviewed the reports of anti-NMDAR encephalitis′s animal models in recent years, and discussed the advantages and limitations of each model, in order to provide a more suitable animal model for further research on anti-NMDAR encephalitis.

Role of NMDA receptors in sevoflurane anesthesia-caused necroptosis in hippocampal neurons of aged mice / 中华麻醉学杂志

Objective:To evaluate the role of N-methyl-D-aspartate receptors (NMDA receptors) in sevoflurane anesthesia-caused necroptosis in hippocampal neurons of aged mice.Methods:Ninety clean-grade healthy male C57BL/6 mice, aged 18 months, weighing 27-30 g, were divided into 3 groups ( n=30 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S) and sevoflurane anesthesia plus NMDA receptor antagonist memantine hydrochloride group (group S+ M). Mice inhaled 3% sevoflurane for 2 h for 3 consecutive days in S group and S+ M group, and memantine hydrochloride 20 mg/kg was intraperitoneally injected at 1 h before each inhalation of sevoflurane in S+ M group.Mice only inhaled pure oxygen for 2 h in group C. Ten mice of each group were selected on 1 day before anesthesia and 3 and 7 days after anesthesia to perform Morris water maze test.The mice were sacrificed immediately after Morris water maze test, and hippocampus was removed for microscopic examination of pathological changes (with a light microscope) and for determination of the necroptosis rate of neurons and cytoplasmic free calcium concentration([Ca 2+ ] i)(by flow cytometry), and expression of NMDA receptor subtypes GluN2A, GluN2B and receptor-interacting protein kinase 1 (RIP1) (by Western blot). Results:Compared with group C, the escape latency was significantly prolonged, and the frequency of crossing the original platform was decreased, and the [Ca 2+ ] i and neuronal necroptosis rate in the hippocampus were increased at each time point after anesthesia, and the expression of GluN2A, GluN2B and RIP1 was up-regulated( P<0.05), and the pathologic changes were accentuated in S group and S+ M group.Compared with group S, the escape latency was significantly shortened, and the frequency of crossing the original platform was increased, and the [Ca 2+ ] i and neuronal necroptosis rate in the hippocampus were decreased at each time point after anesthesia, and the expression of GluN2A, GluN2B and RIP1 was down-regulated ( P<0.05), and the pathologic changes were attenuated in group S+ M. Conclusions:NMDA receptors are involved in the process of cognitive dysfunction induced by sevoflurane anesthesia in aged mice, and the mechanism may be related to the promotion of necrptosis in hippocampal neurons.

Diffusion tensor imaging in assessment of structural brain networks in patients with anti-N-methyl-D-aspartate receptor encephalitis / 中华放射学杂志

Objective:To explore the alteration of structural network, cognitive scores in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, as well as the relationship between cognitive impairment and changes of structural networks in patients with NMDAR encephalitis.Methods:This study was a retrospective study. A total of 39 patients with anti-NMDAR encephalitis were recruited as the autoimmune encephalitis group (AE group) from the First Affiliated Hospital of Chongqing Medical University between September 2012 to December 2019, and 32 healthy volunteers with normal results of routine head MR examinations and no history of central nervous system diseases were recruited as the health control group (HC group). There were 16 males and 23 females, aged from 13 to 66 (34±15) years, with duration of disease from 11 to 110 (31±20) days in AE group, and there were 16 males and 23 females, aged from 13 to 66 (34±15) years in HC group. All subjects underwent diffusion tensor imaging (DTI) scan and cognitive function evaluation. The brain structural networks of two groups were constructed by deterministic fiber tracking techniques, and the differences of global topological properties [clustering coefficient (C p), shortest path length (L p), local efficiency (E loc), global efficiency (E glob), normalized C p (γ), normalized L p (λ), small-worldness (σ)] and local topological properties between two groups were analyzed by the graph theory approch. The correlations between characteristics of brain structural networks and cognitive function scores were further analyzed. Results:There was no significant difference in age and gender distribution between the AE group and HC group ( P>0.05). The C p [0.005(0.004, 0.007)], γ (1.76±0.13), λ (0.51±0.03) and σ value (1.57±0.13) of AE group were decreased when compared with HC group [the values were 0.007(0.004,0.017), 2.13±0.63, 0.55±0.06 and 1.73±0.36 each] ( Z=-939.00, t=-3.58, t=-4.16, t=-2.58, P<0.05). Compared with HC group, nodal efficiencies in the left middle frontal gyrus (orbital part), left and right supplementary motor areas, left olfactory cortex, left gyrus rectus, bilateral insula, left postcentral gyrus, left paracentral lobule and right heschl gyrus were changed ( P<0.05). There were five identical hub regions which contains the left middle occipital gyrus, bilateral supplementary motor areas and precuneus in both groups. However, in the AE group, three hub regions of the left middle occipital gyrus and bilateral middle temporal gyrus were reduced, and the left precentral gyrus was increased as hub region. The nodal efficiencies of the left supplementary motor areas ( r=0.393, P=0.013), right supplementary motor areas ( r=0.384, P=0.016) and left paracentral lobule ( r=0.356, P=0.026) were positively correlated with the montreal cognitive assessment scores. Conclusion:The white matter is extensively impaired in anti-NMDAR encephalitis patients and the changes of topological properties in several brain regions are correlated with cognitive decline.

Molecular Mechanism of Wendantang Against Schizophrenia in Rats： An Exploration Based on miRNA-219， NR2B， DISC1 and CaMKⅡγ / 中国实验方剂学杂志

ObjectiveTo study the effects of Wendantang on the expression of miRNA-219， N-methyl-D-aspartate receptor 2B （NR2B）， disrupted in schizophrenia 1 （DISC1）， and Ca2+/calmodulin-dependent protein kinase Ⅱγ （CaMKⅡγ） in the frontal lobe of rats with schizophrenia. MethodSixty rats were randomly divided into six groups， namely normal group， model group， high-， medium-， and low-dose Wendantang groups， and clozapine group， with 10 rats in each group. Rats in high-， medium-， and low-dose Wendantang groups were intragastric with 40， 20， and 10 g·kg-1 Wendantang， and the ones in clozapine group were intragastric with 0.02 g·kg-1 clozapine， those in normal and model group were intragastric with equal volume of normal saline， once a day. After 21 days of administration， rats in all groups except for the normal group were injected with 0.6 mg·kg-1 dizocilpine maleate （MK-801） into the left abdominal cavity for inducing acute schizophrenia. The stereotypic behavior and ataxia in rats were scored according to SAMS and HOFFMAN criteria. The morphological changes in the prefrontal cortex were observed by hematoxylin-eosin （HE） staining. The protein expression levels of NR2B, DISC1 and CaMKⅡγ in the frontal lobe was detected by Western blot. The mRNA expression levels of miRNA-219 was detected by real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）. ResultCompared with normal group， the model group exhibited significantly increased stereotypic behavior and ataxia scores （P<0.01）， karyopyknosis and karyolysis in most neurons of the prefrontal cortex， and down-regulated NR2B， DISC1， and CaMKⅡγ protein expression （P<0.01） and miRNA-219， NR2B， DISC1， and CaMKⅡγ mRNA expression （P<0.01）. Compared with model group， Wendantang high-， medium-， and low-doses group lowered the scores of stereotypic behavior and ataxia at 50， 60 mmin（P<0.05，P<0.01）. In high- and medium-dose Wendantang groups， the neurons in the prefrontal cortex were densely arranged. The karyopyknosis and karyolysis were alleviated to varying degrees. The NR2B protein expression in the frontal lobe was up-regulated （P<0.01）. In the medium- and low-dose Wendantang groups， the DISC1 protein expression in the frontal lobe was up-regulated （P<0.05，P<0.01）. Wendantang at each dose significantly increased the CaMKⅡγ protein expression （P<0.05） and miRNA-219， NR2B， DISC1， and CaMKⅡγ mRNA expression in the frontal lobe （P<0.05，P<0.01）. ConclusionWendantang improves the scores of stereotypical behavior and ataxia， relieves the karyopyknosis and karyolysis of neurons in the prefrontal cortex， and increases the expression levels of miRNA-219， NR2B， DISC1， and CaMKⅡγ of rats with schizophrenia， so as to alleviate the schizophrenic-like symptoms and schizophrenia.

Advances in N-methyl-D-aspartate Receptor Signaling Pathway and Mechanism of the Pathway-mediated Apoptosis / 中国医学科学院学报

N-methyl-D-aspartate receptor (NMDAR),an important ionic glutamate receptor and a ligand and voltage-gated ion channel characterized by complex composition and functions and wide distribution,plays a key role in the pathological and physiological process of diseases or stress states.NMDAR can mediate apoptosis through different pathways such as mitochondrial and endoplasmic reticulum damage,production of reactive oxygen species and peroxynitrite,and activation of mitogen-activated protein kinase and calpain.This paper reviews the structure,distribution,and biological characteristics of NMDAR and the mechanisms of NMDAR-mediated apoptosis.