Modified Xiaoyaosan Alleviates Depression-like Behaviors by Regulating Activation of Hippocampal Microglia Cells in Rat Model of Juvenile Depression / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Baihuan Xiaoyao Decoction （Xiaoyaosan added with Lilii Bulbus and Albiziae Cortex） in alleviating depression-like behaviors of juvenile rats by regulating the polarization of microglia. MethodSixty juvenile SD rats were randomized into normal control， model， fluoxetine， and low-， medium-， and high-dose （5.36， 10.71， 21.42 g·kg-1， respectively） Baihuan Xiaoyao decoction groups. The rat model of juvenile depression was established by chronic unpredictable mild stress （CUMS）. The sucrose preference test （SPT） was carried out to examine the sucrose preference of rats. Forced swimming test （FST） was carried out to measure the immobility time of rats. The open field test （OFT） was conducted to measure the total distance， the central distance， the number of horizontal crossings， and the frequency of rearing. Morris water maze （MWM） was used to measure the escape latency and the number of crossing the platform. The immunofluorescence assay was employed to detect the expression of inducible nitric oxide synthase （iNOS， the polarization marker of M1 microglia） and CD206 （the polarization marker of M2 microglia）. Real-time polymerase chain reaction was employed to determine the mRNA levels of iNOS， CD206， pro-inflammatory cytokines ［tumor necrosis factor （TNF）-α， interleukin （IL）-1β， and IL-6］ and anti-inflammatory cytokines （IL-4 and IL-10） in the hippocampus. Western blotting was employed to determine the protein levels of iNOS and CD206 in the hippocampus. The levels of IL-4 and IL-6 in the hippocampus were detected by enzyme-linked immunosorbent assay. ResultCompared with the normal control group， the model rats showed a reduction in sucrose preference （P<0.05）， an increase in immobility time （P<0.05）， decreased motor and exploratory behaviors （P<0.05）， and weakened learning and spatial memory （P<0.05）. In addition， the model rats showed up-regulated mRNA and protein levels of iNOS and mRNA levels of IL-1β， IL-6， and TNF-α （P<0.05）. Compared with the model group， Baihuan Xiaoyao decoction increased the sucrose preference value （P<0.05）， shortened the immobility time （P<0.01）， increased the motor and exploratory behaviors （P<0.05）， and improved the learning and spatial memory （P<0.01）. Furthermore， the decoction down-regulated the positive expression and protein level of iNOS， lowered the levels of TNF-α， IL-1β， and IL-6 （P<0.01）， promoted the positive expression of CD206， and elevated the levels of IL-4 and IL-10 （P<0.01） in the hippocampus of the high dose group. Moreover， the high-dose Baihuan Xiaoyao decoction group had higher sucrose preference value （P<0.01）， shorter immobility time （P<0.01）， longer central distance （P<0.01）， stronger learning and spatial memory （P<0.01）， higher positive expression and protein level of iNOS （P<0.01）， lower levels of TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01）， lower positive expression and mRNA level of iNOS （P<0.05）， and higher levels of IL-4 and IL-10 （P<0.05， P<0.01） than the fluoxetine group. ConclusionBaihuan Xiaoyao decoction can improve the depression-like behavior of juvenile rats by inhibiting the M1 polarization and promoting the M2 polarization of microglia in the hippocampus.

Correlación entre escalas visuales de atrofia entorrinal y temporomesial con volumetría hipocampal / Correlation between visual scales of entorhinal and temporomesial atrophy with hippocampal volumetry

Resumen Objetivo: En pacientes con enfermedad de Alzheimer (EA) se han descrito cambios neuropatológicos tempranos en la corteza entorrinal, que anteceden el compromiso temporomesial. La evaluación de la atrofia hipocampal mediante escalas visuales y volumetría son herramientas útiles en la valoración de pacientes con deterioro cognitivo. Nuestro objetivo es establecer la correlación entre la evaluación visual de la atrofia de la corteza entorrinal (ACE), la atrofia temporomesial (ATM) y el volumen hipocampal. Material y métodos: Estudio retrospectivo de corte transversal. Se incluyeron pacientes con queja cognitiva y resonancia magnética (RM) cerebral. Se utilizaron escalas visuales de ACE y ATM. Se midió el volumen hipocampal mediante el software volBrain 1.0. Resultados: Se incluyeron 48 pacientes, 31 eran mujeres (64,6%). Mediana de edad: 76,5 (RIQ: 69-83). La correlación entre las escalas visuales ACE y la ATM del lado derecho fue de 0,67 p < 0,0001) y del lado izquierdo de 0,69 (p < 0,0001). Encontramos correlación negativa moderada entre la ACE y el volumen hipocampal, del lado derecho fue de –0,59 (p < 0,0001) y del lado izquierdo de –0,42 (p = 0,003). Conclusión: La escala de ACE muestra moderada correlación con la escala de ATM y con el volumen hipocampal. Su uso podría aportar información valiosa para valoración de trastornos cognitivos.

Abstract Objective: In patients with Alzheimer’s disease (AD), early neuropathological changes in the entorhinal cortex have been described, which precede temporomesial involvement. The evaluation of hippocampal atrophy using visual scales and volumetry are useful tools in the assessment of patients with cognitive impairment. Our objective is to establish the correlation between the visual evaluations of entorhinal cortex atrophy (ECA), temporomesial atrophy (TMA), and hippocampal volume. Material and methods: Retrospective cross-sectional study. Patients with cognitive complaint and brain magnetic resonance imaging (MRI) were included. ACE and TMA visual scales were used. Hippocampal volume was measured using the volBrain 1.0 software. Results: Forty-eight patients were included, 31 were women (64.6%). Median age was 76.5 (IQR: 69-83). The correlation between ECA and TMA on the right side was 0.67 (p < 0.0001) and on the left side was 0.69 (p < 0.0001). We found a negative moderate correlation between ECA and hippocampal volume, on the right side it was –0.59 (p < 0.0001) and on the left side it was –0.42 (p = 0.003). Conclusion: The ECA scale shows high correlation with the TMA scale and moderate correlation with hippocampal volume. Its use could provide valuable information for the assessment of cognitive disorders.

Epileptogénesis y corteza piriforme: entendiendo a la epilepsia del lóbulo temporal más allá del hipocampo / Epileptogenesis and the piriform cortex: understanding temporal lobe epilepsy beyond the hippocampus

Introducción: Con la experiencia de los registros electroencefalográficos invasivos y el fracaso quirúrgico después de la cirugía, se ha hecho evidente que la epilepsia del lóbulo temporal es mucho más compleja de lo que se creía, y en la actualidad es considerada una enfermedad de redes anatomofuncionales y no de lesiones estructurales. Contenido: La información neurofisiológica e imagenológica actual permite concluir que en esta epilepsia están involucradas varias redes neuronales temporales y extratemporales que contribuyen a la extensión de la zona epileptógena. Una forma de entender el concepto de red epiléptica en la epilepsia del lóbulo temporal es a partir del conocimiento de la corteza piriforme. Varios estudios clínicos han mostrado que en pacientes con epilepsia del lóbulo temporal asociada a esclerosis hipocampal existe una disfunción interictal del procesamiento olfatorio que es más significativa, en comparación con pacientes con epilepsia focal extrahipocampal y controles sanos. Esta alteración es, probablemente, la consecuencia de una red neuronal disfuncional que se extiende más allá del hipocampo y que afecta a otras estructuras cercanas, incluida la corteza piriforme. Conclusión: En este artículo llevamos a cabo una revisión narrativa de la literatura con el objetivo de establecer un vínculo entre la corteza piriforme y la epileptogénesis del lóbulo temporal, y demostramos que esta enfermedad es la consecuencia de una disfunción de redes neuronales que no depende exclusivamente de una anormalidad estructural en el hipocampo o en estructuras cercanas.

Introduction: With the experience of invasive EEG recordings and surgical failure after surgery, it has become clear that temporal lobe epilepsy is much more complex than previously thought, and currently, is conceptualized as a disease of anatomical networks instead of structural lesions. Content: The current neurophysiological and imaging information allows us to conclude that several temporal and extratemporal anatomical networks are involved in this type of epilepsy. One way of understanding the concept of the epileptic network in temporal lobe epilepsy is from the knowledge of the piriform cortex. Several clinical studies have shown that in patients with temporal lobe epilepsy associated with hippocampal sclerosis exists an interictal dysfunction of olfactory processing that is more significant compared to patients with focal extra-hippocampal epilepsy and healthy controls. This alteration is probably the consequence of a dysfunctional neural network that extends beyond the hippocampus and affects other nearby structures, including the piriform cortex. Conclusion: In this article, we carry out a narrative review of the literature with the aim of establishing a link between the piriform cortex and temporal lobe epileptogenesis, demonstrating that this disease is the consequence of a dysfunctional network that does not depend exclusively of a hippocampal structural abnormality.

Neuroestimulación del nervio vago, hipocampal y de núcleos anteriores y centromedianos del tálamo en epilepsia temporal: revisión de la literatura / Neurostimulation of the vagus nerve, hippocampal and anterior and centromedian nuclei of the thalamus in temporal epilepsy: literature review

Introducción: En pacientes con epilepsia del lóbulo temporal refractarios que no son candidatos a cirugía, se debe considerar la estimulación eléctrica cerebral como una opción. Contenido: La estimulación eléctrica cerebral es la administración directa de pulsos eléctricos al tejido nervioso que permite modular un sustrato patológico, interrumpir la manifestación clínica de las crisis y reducir la gravedad de estas. Así, dada la importancia de estos tratamientos para los pacientes con epilepsia del lóbulo temporal refractaria, se hace una revisión de cuatro tipos de estimulación eléctrica. La primera, la del nervio vago, es una buena opción en crisis focales y crisis generalizadas o multifocales. La segunda, la del hipocampo, es más útil en pacientes no candidatos a lobectomía por riesgo de pérdida de memoria, con resonancia magnética normal o sin esclerosis mesial temporal. La tercera, la del núcleo anterior, es pertinente principalmente en pacientes con crisis focales, pero debe realizarse con precaución en pacientes con alto riesgo de cambios cognitivos, como los ancianos, o en los que presentan alteración del estado de ánimo basal, y, por último, la del núcleo centromediano se recomienda para el tratamiento crisis focales en el síndrome de Rasmussen y crisis tónico-clónicas en el síndrome de Lennox-Gastaut. Conclusiones: El interés por la estimulación eléctrica cerebral ha venido aumentando, al igual que las estructuras diana en las cuales se puede aplicar, debido a que es un tratamiento seguro y eficaz en pacientes con epilepsia del lóbulo temporal para controlar las crisis, pues disminuye la morbimortalidad y aumenta la calidad de vida.

Introduction: In patients with refractory temporal lobe epilepsy who are not candidates for surgery, electrical brain stimulation should be considered as another option. Contents: Electrical brain stimulation is the direct administration of electrical pulses to nerve tissue that modulates a pathological substrate, interrupts the clinical manifestation of seizures, and reduces their severity. Thus, given the importance of these treatments for patients with refractory temporal lobe epilepsy, four types of electrical stimulation are reviewed. The first, vagus nerve stimulation, is a good option in focal seizures and generalized or multifocal seizures. The second, hippocampal stimulation, is more useful in patients who are not candidates for lobectomy due to the risk of memory loss, with normal MRI or without mesial temporal sclerosis. The third, the anterior nucleus, is mainly in patients with focal seizures, but with caution in patients at high risk of cognitive changes such as the elderly, or in those with baseline mood disturbance and, finally, the centromedian nucleus is recommended for the treatment of focal seizures in Rasmussen's syndrome and tonic-clonic seizures in Lennox-Gastaut syndrome. Conclusions: the interest in brain electrical stimulation has been increasing as well as the target structures in which it can be applied because it is a safe and effective treatment in patients with temporal lobe epilepsy to control seizures, decreasing morbidity and mortality and increasing quality of life

Role of Aluminium in Alzheimer’s disease: Ultrastructural Study in Rat Hippocampus

Background: Exposure to high levels of aluminium (Al) leads to neurotoxicity. Hippocampus is one of the preferred sites of aluminium accumulation. Nevertheless, the role of Al in Alzheimer’s disease (AD) remains controversial and there is little proof directly interlinking Al to AD. Aims: The present study was undertaken to find out the occurrence of AD pathogenesis in Hippocampus under moderate aluminium exposure in rats. Materials and Methods: Adult rats were divided into control (C) and aluminium treated (E) groups having eight animal each. The rats in group E were exposed to aluminium 4.2 mg/kg body weight for three months with due approval from Institute Animal Ethics Committee. The hippocampus was processed for histopathological and electron microscopy observation. Results: Moderate Al intake produces significant reduction in the count of Pyramidal cells in hippocampus identified by shrunken cells as well as pyknosis in cell bodies. The differences between the cell numbers in all groups were found to be statistically significant (P < 0.05). Cornu Ammonis (CA) exhibited significantly reduced nissl bodies with a marked reduction in neuronal cell loss. Neurofibrillary tangle and plaques were not seen in the given dose of Al exposure. Electron microscopy from experimental group showed that the majority of neurons were disintegrating, the nuclear membrane has ruptured, and nucleoli appeared significantly distorted. The chromatin condensed and the mitochondria had disintegrated. Many vacuoles and lipofuscin sediment in cytoplasm, as compared to the control group noted. Conclusion: Present data demonstrated that moderate chronic aluminium exposure 4.2mg/kg body weight induced neurodegeneration in hippocampus but not significant for Alzheimer’s disease pathogenesis.

Rhinal and hippocampal event-related potentials as epileptogenic zone markers in the pre-surgical evaluation of temporal epilepsies: a systematic review / Potenciais evocados rinais e hipocampais como marcadores da zona epileptogênica na avaliação pré-cirúrgica das epilepsias temporais: uma revisão sistemática

Abstract Background Cognitive event-related potentials (ERPs) allow for lateralization of the epileptogenic zone (EZ) to estimate the reserve of memory in the contralateral non-epileptogenic hemisphere, and to investigate the prognosis of temporal lobe seizure control in unilateral temporal lobe epilepsy (TLE). Objective To define the accuracy of cognitive evoked anterior mesial temporal lobe (AMTL-N400) and P600 potentials in detecting the epileptogenic zone in temporal lobe epilepsy (TLE), and second, to evaluate the possibility of using them as markers of cognitive outcome. Methods The systematic review using Medline/PubMed, Embase, and Lilacs database was conducted in September 2021. Only articles published in English from 1985 to June 2021 were included. We searched for studies with: (1) depth intracranial electroencephalography (iEEG) recordings analysis of rhinal and hippocampal activity (2) correlations between ERP results obtained in the mesial temporal regions (AMTL-N400 and P600) and the epileptogenic zone. Results Six out of the seven studies included in this review defined the laterality of the epileptogenic zone (EZ) during presurgical investigation using ERPs. One study showed that the contralateral AMTL-N400 predicts seizure control. Another study found correlation between the amplitudes of the right AMTL-N400 and postoperative memory performance. Conclusions There is evidence that the reduced amplitude of the AMTL-N400 has high accuracy in identifying the epileptogenic zone, as it does in estimating the extent of seizure control and memory impairment in postoperative patients.

Resumo Antecedentes Potenciais relacionados a eventos (PREs) cognitivos permitem a lateralização da zona epileptogênica (ZE), estimar a reserva de memória no hemisfério contralateral não-epileptogênico, e estimar o prognóstico pós-operatório em pacientes com epilepsia do lobo temporal (ELT) unilateral quanto ao controle de crises. Objetivo Definir a acurácia dos potenciais evocados cognitivos do lobo temporal mesial anterior (LTMA-N400) e P600 na detecção da zona epileptogênica na epilepsia do lobo temporal (ELT), além de avaliar a possibilidade de usá-los como marcadores de desfecho cognitivo. Métodos A revisão sistemática foi realizada em setembro de 2021 usando as bases de dados Medline/PubMed, Embase e Lilacs. Apenas artigos publicados em inglês no período entre 1985 e junho de 2021 foram incluídos. Buscamos estudos com: (1) análises dos registros de electroencefalografia intracraniana (EEGi) da atividade rinal e hipocampal (2) correlações entre os resultados de PREs obtidos nas regiões temporais mesiais (AMTL-N400 e P600) e a zona epileptogênica. Resultados Seis dos sete estudos incluídos nesta revisão definiram a lateralidade da zona epileptogênica (ZE) durante a investigação pré-cirúrgica usando PREs. Um estudo mostrou que o AMTL-N400 contralateral prediz o controle das crises. Outro estudo encontrou correlação entre as amplitudes do AMTL-N400 direito e o desempenho da memória pós-operatória. Conclusões Há evidências de que a amplitude reduzida do AMTL-N400 tem alta precisão na identificação da zona epileptogênica, assim como na estimativa do prognóstico quanto ao controle de crises a longo prazo e prejuízo da memória em pacientes submetidos à cirurgia ressectiva.

Brain glucose hypometabolism and hippocampal inflammation in Goto-Kakizaki rats

Brain glucose hypometabolism and neuroinflammation are early pathogenic manifestations in neurological disorders. Neuroinflammation may also disrupt leptin signaling, an adipokine that centrally regulates appetite and energy balance by acting on the hypothalamus and exerting neuroprotection in the hippocampus. The Goto-Kakizaki (GK) rat is a non-obese type 2 diabetes mellitus (T2DM) animal model used to investigate diabetes-associated molecular mechanisms without obesity jeopardizing effects. Wistar and GK rats received the maintenance adult rodent diet. Also, an additional control group of Wistar rats received a high-fat and high-sugar diet (HFHS) provided by free consumption of condensed milk. All diets and water were provided ad libitum for eight weeks. Brain glucose uptake was evaluated by 2-deoxy-2-[fluorine-18] fluoro-D-glucose under basal (saline administration) or stimulated (CL316,243, a selective β3-AR agonist) conditions. The animals were fasted for 10-12 h, anesthetized, and euthanized. The brain was quickly dissected, and the hippocampal area was sectioned and stored at -80°C in different tubes for protein and RNA analyses on the same animal. GK rats exhibited attenuated brain glucose uptake compared to Wistar animals and the HFHS group under basal conditions. Also, the hippocampus of GK rats displayed upregulated leptin receptor, IL-1β, and IL-6 gene expression and IL-1β and the subunit of the transcription factor NF-κB (p-p65) protein expression. No significant alterations were detected in the hippocampus of HFHS rats. Our data indicated that a genetic predisposition to T2DM has significant brain deteriorating features, including brain glucose hypometabolism, neuroinflammation, and leptin signaling disruption in the hippocampal area.

Effect of silibinin and trans-chalcone in an Alzheimer's disease-like model generated by insulin amyloids

Amyloid fibrils are characteristic of several disorders including Alzheimer's disease (AD), with no cure or preventive therapy. Diminishing amyloid deposits using aromatic compounds is an interesting approach toward AD treatment. The present study examined the anti-fibrillogenic effects of silibinin and trans-chalcone in vitro, in vivo, and in silico on insulin amyloids. In vitro incubation of insulin at 37°C for 24 h induced amyloid formation. Addition of trans-chalcone and silibinin to insulin led to reduced amounts of fibrils as shown by thioflavin S fluorescence and Congo red absorption spectroscopy, with a better effect observed for silibinin. In vivo bilateral injection of fibrils formed by incubation of insulin in the presence or absence of silibinin and trans-chalcone or insulin fibrils plus the compounds in rats' hippocampus was performed to obtain AD characteristics. Passive avoidance (PA) test showed that treatment with both compounds efficiently increased latency compared with the model group. Histological investigation of the hippocampus in the cornu ammonis (CA1) and dentate gyrus (DG) regions of the rat's brain stained with hematoxylin-eosin and thioflavin S showed an inhibitory effect on amyloid aggregation and markedly reduced amyloid plaques. In silico, a docking experiment on native and fibrillar forms of insulin provided an insight onto the possible binding site of the compounds. In conclusion, these small aromatic compounds are suggested to have a protective effect on AD.

Clinical application of LinaTech linear accelerator VenusX to hippocampal protection in whole-brain radiotherapy / 中华放射医学与防护杂志

Objective:To compare the dosimetric differences between the VenusX accelerator with an orthogonal dual-layer multi-leaf collimator (MLC) and the Varian′s CLINAC IX and EDGE accelerators with a single-layer MLC for hippocampus protection in the whole-brain radiotherapy (WBRT).Methods:Forty patients with multiple brain metastases admitted to the Radiotherapy Department of the Shanghai General Hospital from June 2021 to February 2023 were selected in this study. Three whole-brain treatment plans were designed based on the above three accelerators for each patient. Under the same prescription dose, radiation field, and plan constraints, the three plans were compared in terms of the dosimetric differences in target volumes, hippocampi, and adjacent organs at risk (OARs), as well as the execution efficiency.Results:For the planning target volume (PTV), there were statistically significant differences in approximate maximum dose ( D2) between the VenusX and IX plans ( t = 4.94, P < 0.05), in approximate minimum dose ( D98) between the VenusX and EDGE plans ( t = 5.98, P < 0.05), in the target conformity indices (CIs) between VenusX plan and EDGE plans, and between the VenusX and IX plans ( t = -6.84, -14.30; P < 0.05), and dose homogeneity indices (HIs) between the VenusX and IX plans ( t = 3.48, P < 0.05). For OARs, the maximum doses ( Dmax) and average doses ( Dmean) to bilateral hippocampi of the VenusX plan were lower than those of the EDGE and IX plans ( t = 8.59-17.11, P < 0.05); the maximum doses ( Dmax) to bilateral lenses, bilateral optic nerves, and optic chiasma of the VenusX plan were lower than those of the other two plans ( t = 2.10-20.80, P < 0.05); and the differences between the maximum doses ( Dmax) to the brain stem of the VenusX and EDGE plans were statistically significant ( t = 3.86, P < 0.05). In terms of plan execution efficiency, the number of machine jumps (MU) and the treatment time of the VenusX plan were higher than those of the EDGE and IX plans, with statistically significant differences ( t = -56.48, -56.90, P < 0.05). Conclusions:The doses to target volumes of the three treatment plans all meet the prescription requirements, and the VenusX plan outperforms the EDGE and IX plans in the protection of OARs. Despite the reduced execution efficiency, the VenusX plan shortens the actual treatment time by improving the dosage rate, thus meeting the clinical requirements.

Flavonoid compounds improve hippocampal neuro-genesis and cognitive dysfunction in mice / 中国药理学与毒理学杂志

OBJECTIVE To investigate the improve-ment functions of flavonoid compounds on temozolomide(TMZ)-,aging-or AD model-induced dysregulation of hip-pocampal NSC lineage progression,retardancy of den-dritic spine maturation in new-born neurons,as well as impairment of hippocampal-related learning and memory.METHODS We applied 30-week-old neural stem cell(NSC)specific promoter Nestin-GFP and NestinCreERT2:Rosa26-LSL-tdTomato transgenic mice and 16-week-old AD model 5XFAD transgenic mice,together with hippo-campal microinjection(ih),endogenous fluorescence trac-ing and immunofluorescent staining.RESULTS Both fla-vonoid compound A and its functional derivative flavo-noid compound B dose-dependently improved TMZ-,aging-or AD-induced defects of hippocampal NSC lin-eage progression and the maturation of dendritic spines of newborn neurons,thereby improving hippocampus related learning and memory.CONCLUSION This paper provides a new idea and treatment strategy for the devel-opment of new flavonoids that can promote neurogene-sis for neurodegenerative diseases and aging.

Effects of Erastin on depressive- and anxiety-like behavior and the expression of hippocampal ferroptosis-related proteins in rats / 中华行为医学与脑科学杂志

Objective:To explore the effects of intrahippocampal injection of ferroptosis inducer Erastin on depressive- and anxiety-like behavior and the expression of ferroptosis-related proteins in rats.Methods:Forty 6-week-old healthy male Sprague-Dawley rats were randomly divided into five groups ( n=8/group): Control group, Erastin low-dose(200 ng/μL) group, Erastin medium-dose(400 ng/μL) group, Erastin high-dose group(600 ng/μL) and lipopolysaccharide (LPS, 10 μg/L) group.After the intrahippocampal injection of Erastin(2.5 μL per side), body weight, and behavioral tests, including sucrose preference test (SPT), forced swimming test (FST), open field test (OFT), and elevated plus maze (EPM), were performed to evaluate depressive- and anxiety-like phenotypes from the fourth day after injection.The levels of ferroptosis-related proteins and mRNA, including glutathione peroxidase 4 (GPX4), cyclo-oxygenase 2 (COX2), ferritin heavy polypeptide 1 (FTH1), long-chain fatty acyl-CoA synthetase 4 (ACSL4), solute carrier family 7 member 11 (SLC7A11) were measured using real-time quantitative PCR and Western blot analysis.SPSS 22.0 software was used for statistical analysis.One-Way ANOVA was used for multi-group comparison, and LSD was used for further pound-wise comparison. Results:(1)Body weight and behavioral tests: there were no statistically significant differences in baseline body weight and behavioral tests in these groups ( F=0.02-1.15, all P>0.05). After intrahippocampal injection, compared with the control group, medium-dose Erastin induced depression-like behaviors in rats more significantly, as indicated by reduced bodyweight ((245.20±5.24)g, (267.45±13.16)), sucrose preference in SPT ((32.14±8.51)%, (68.17±13.67)%), central time in OFT ((6.01±2.57)s, (16.49±7.21)s), percentage of time in open arm in EPM ((5.00±3.83)%, (19.63±5.91)%) and increased immobility time in FST ((37.00±7.58)s, (12.50±5.51)s) and percentage of time in closed arm in EPM ((89.43±4.77)%, (59.96±9.91)%), and there were statistically significant differences in these groups (all P<0.05). (2)The expression of ferroptosis-related indicators: after intrahippocampal injection, the expression of mRNA ( F=2.23, 8.37, 2.91, 7.60, 3.16, all P<0.05) and protein ( F=3.31, 40.13, 8.52, 3.70, 70.79, all P<0.05) of FTH1, GPX4, SLC7A11, COX2 and ACSL4 in hippocampus were statistically significant differences in the 5 groups.The mRNA and protein levels of FTH1, GPX4 and SLC7A11 in Erastin medium-dose group were lower than those in the control group (all P<0.05), while the mRNA and protein levels of COX2 and ACSL4 were higher than those in the control group (all P<0.05). Conclusion:Intrahippocampal microinjection of Erastin(400 ng/μL) can induce ferroptosis in hippocampus of rats and can also induce depressive-like behaviors in rats.

Effects of human umbilical cord mesenchymal stem cells exosomes on hippocampal microglia polarization and neuronal apoptosis in depressed model mice / 中华行为医学与脑科学杂志

Objective:To investigate the effects of human umbilical cord mesenchymal stem cells exosomes (hucMSC-Exo) on depression-like behavior and polarization dynamic transition of hippocampal microglia in chronic unpredictable mild stress(CUMS) mice.Methods:The hucMSC was isolated, cultured, and the 5th generation hucMSC-Exo was extracted by ultracentrifugation and identified.Biological markers of CD9 and CD63 of hucMSC-Exo were detected by Western blot.A total of 12 SPF grade male C57BL/6J mice were randomly selected to establish depression model by CUMS method at the same time, and relevant behavioral experiments, including opening field test (OFT) and forced swimming test (FST) were used to detect changes of depression-like behavior in CUMS mice. After modeling, 12 mice were randomly divided into two groups, with 6 mice in each group. One group of mice was the exosome treatment group (CUMS+ Exo group) after stereotactic brain injection of hucMSC-Exo in the hippocampus, and the other group was the CUMS group. The expression of inflammatory signals in the hippocampus of mice in both groups were detected by micro PET/CT scanning technique. The proportion of M2-type microglia and M1-type microglia in the hippocampus of mice was detected by tissue immunofluorescence. β3-tubulin immunofluorescence staining was used to detect the length changes of neuronal axons in the depressed cell model constructed with corticosterone (CORT). EdU staining was used to detect neuronal proliferation. TUNEL staining was used to observe the apoptosis of neurons in the hippocampus of mice.Statistical analysis was conducted by GraphPad 8.0 software, and t-test was used for inter group comparison. Results:Under the electron microscope, hucMSC-Exo showed typical " double-layer cup-like" small vesicle-like changes and the particle diameter was about 100 nm.Western blot confirmed the expression of lconic proteins of CD9 and CD63. In the micro PET/CT scans, the uptake of [18F]DPA-714 in the CUMS+ Exo group was lower than that of the CUMS group, and the difference was statistically significant ((0.91±0.02)g/mL, (0.81±0.05)g/mL, t=4.54, P=0.001 1). In the opening field test, the percentage of central path length ((3.40±0.44)%, (5.17±0.90)%, t=4.33, P=0.001 5) and the time spent on the central path ((7.04±0.60)s, (10.22±1.41)s, t=6.02, P=0.000 1) in CUMS+ Exo group were higher than those in CUMS group, while the total distances of the two groups were not statistically significant ( t=0.48, P>0.05). In the forced swimming test, the immobility time in the CUMS+ Exo group was less than that in the CUMS group ((152.33±7.28) s, (133.50±4.32) s, t=5.45, P=0.000 3). In tissue immunofluorescence experiments, compared with the CUMS group, the proportion of M2-type microglia of hippocampus in the CUMS+ Exo group((0.33±0.04), (0.59±0.12), t=5.11, P=0.000 5)increased and the proportion of M1-type microglia ((0.56±0.06), (0.41±0.03), t=5.15, P=0.000 4) decreased in the CUMS+ Exo group. β3-tubulin-labeled immunofluorescence results showed an increase of neuronal axon length in the CORT+ Exo group compared with that in the CORT group((3.99±0.99) μm, (6.76±1.11) μm, t=6.10, P=0.000 1). The results of cell proliferation test showed an increase of proliferation rate in the CORT+ Exo group compared with that in the CORT group((0.74±0.07), (0.64±0.03), t=3.32, P=0.001 8). In the TUNEL staining experiment, the apoptosis rate of neurons in the hippocampal region of mice in the CUMS+ Exo group was lower than that of CUMS group ((0.24±0.04), (0.39±0.04), t=6.11, P=0.000 1). Conclusion:hucMSC-Exo can promote the conversion of M1 polarized microglia to M2 type microglia to alleviate depression-like behavior and reduce neuronal apoptosis in CUMS mice.

Construction of an acute toxoplasma encephalitis mouse model by the stereotaxic surgery with RH toxoplasma trophozoites / 西安交通大学学报(医学版)

【Objective】 To construct an acute toxoplasma encephalitis mouse model by observing the pathological changes in the hippocampus of mice infected with Toxoplasma gondii strain RH. 【Methods】 The quantitative RH Toxoplasma gondii (100, 500, and 1 000 trophozoites) were injected into the hippocampal CA1 region of mice by the stereotaxic surgery; the survival status of mice was observed. Giemsa staining was used to observe the changes of toxoplasma in mouse ascites and brain tissue homogenates. Nissl staining and HE staining were used to observe the pathological changes of hippocampal nerve tissue. The distribution of Toxoplasma gondii in brain tissue was observed by immunohistochemical ABC method. 【Results】 The RH Toxoplasma gondii infected mice showed obvious symptoms such as arched back, bristling hair, abdominal distension, subtle tremor and hemiplegia on the fourth day of infection. The survival of mice in 100 trophozoites group was longer, no trophozoites of Toxoplasma gondii were found in ascites, a few pseudocysts were found in brain tissue homogenates after infected for 96 hours, and more trophozoites were found after death. Nysl staining and HE staining showed more tissue necrosis foci and loss of nerve cells in CA1 area after infected 144 h. The injury aggravated with the prolongation of infection time. Toxoplasma trophozoites were found in ascites and brain homogenates of mice in 500 and 1000 trophozoites groups. Nissl staining revealed neuronal loss and massive necrosis in the hippocampus. HE staining showed necrosis and inflammatory cell infiltration. The brain tissue injury significantly aggravated compared with 100 trophozoites group. The distribution of Toxoplasma gondii in the necrotic foci was confirmed by immunohistochemistry. 【Conclusion】 The survival of 100 trophozoite mice infected with Toxoplasma gondii strain RH was longer, and the pathological changes of brain tissue gradually aggravated. The damage was relatively confined to the brain tissue, and the mice showed typical symptoms of toxoplasma encephalitis. Therefore, the mouse model of acute toxoplasma encephalitis can be constructed by localized infection of 100 toxoplasma trophozoites, which can lay a foundation for future research on the mechanism of toxoplasma injury to cranial nerves.

Subchronic Administration of High-dose Monosodium Glutamate Causes Spatial Memory Dysfunction and Structural Deficits of Rat Hippocampus

@#Introduction: The toxicity of high concentration monosodium glutamate (MSG) has become a controversial issue because of its inconsistent results in human and animal studies. This present study aims to evaluate the effect of subchronic high-doses oral administration of MSG on spatial memory performance and hippocampal pyramidal cells number. Methods: This study involved twenty-eight male Wistar rats, which were divided into a control group of NaCl 0.9% and three intervention groups of MSG 1.0 mg/g bodyweight (M1), 2.0 mg/g bodyweight (M2), and 4.0 mg/g bodyweight (M3) for 30 days. Statistical analysis used a One-way ANOVA test. Results: The result showed significant differences in spatial memory on the Morris Water Maze (MWM) test, including path length (p = 0.020) and escape latency (p = 0.011) according to general linear model repeated measurement analysis. The mean difference of estimated hippocampal pyramidal cells total number among the groups showed volume (p = 0.001), numerical density (p = 0.590), and cells number (p = 0.004). Furthermore, Post-Hoc analysis in both spatial memory and hippocampal pyramidal cells showed that the increasing MSG dose from 1.0 to 4.0 mg/g bodyweight led to a decrease in the results of spatial memory performance on the MWM test and a decrease in hippocampal cells. Conclusion: The present study has provided novel quantitative data that subchronic administration of high-dose MSG caused deleterious effects on the spatial memory function and the volume and number of hippocampal pyramidal cells.

Role of Homer1a/mGluR5 signaling pathway in cognitive dysfunction induced by sleep deprivation in aged rats / 中华麻醉学杂志

Objective:To evaluate the role of Homer1a/metabotropic glutamate receptor 5 (mGluR5) signaling pathway in sleep deprivation-induced cognitive dysfunction in aged rats.Methods:One hundred and four SPF healthy male Sprague-Dawley rats, aged 22-24 months, weighing 320-360 g, were divided into 4 groups ( n=26 each) using a random number table method: normal control group (group Control), sleep deprivation+ vehicle group (group SD+ Vehicle), sleep deprivation+ mGluR5 forward allosteric agent CDPPB group (group SD+ CDPPB), and sleep deprivation+ mGluR5 antagonist MPEP group (group SD+ MPEP). A 48-h sleep deprivation model was developed by sleep-deprived rod method. At the beginning of developing the model and 24 h after developing the model, CDPPB 10 mg/kg, MPEP 10 mg/kg and the equal volume of 1% Tween 80 were intraperitoneally injected in group SD+ CDPPB, group SD+ MPEP and group SD+ Vehicle, respectively.Morris water maze and novel object recognition tests were conducted to evaluate cognitive function after development of the model. The expression of Homer1a and mGluR5 in the hippocampus was detected by Western blot, the dendritic spine density in the hippocampal CA1 region was detected by Golgi staining, and the field excitatory postsynaptic potential (fEPSP) slope in the hippocampal CA1 region was detected by isolated electrophysiology. Results:Compared with Control group, the number of crossing the original platform, time of staying at the target quadrant, and novel object recognition index at 1 and 24 h after training were significantly decreased, the expression of Homer1a in the hippocampus was up-regulated, the expression of mGluR5 in the hippocampus was down-regulated, and the density of dendritic spine and fEPSP slope in the hippocampal CA1 region were decreased in group SD+ Vehicle ( P<0.05). Compared with group SD+ Vehicle, the number of crossing the original platform, time of staying at target quadrant, and novel object recognition index at 1 and 24 h after training were significantly increased, the expression of mGluR5 in hippocampus was up-regulated, and the density of dendritic spines and fEPSP slope in the hippocampal CA1 region were increased in group SD+ MPEP( P<0.05), and no statistically significant change was found in the parameters mentioned above in group SD+ CDPPB ( P>0.05). Conclusions:Sleep deprivation impairs the synaptic plasticity of hippocampal neurons by regulating Homer1a/mGluR5 signaling pathway, and thus mediating the process of cognitive dysfunction in aged rats.

Effect of edaravone on ERK-CREB signaling pathway in hippocampus of aged rats with postoperative cognitive dysfunction / 中华麻醉学杂志

Objective:To evaluate the effect of edaravone on the extracellular signal-regulated kinase (ERK)-cAMP responsive element binding protein (CREB) signaling pathway in the hippocampus of aged rats with postoperative cognitive dysfunction (POCD).Methods:Sixty SPF healthy male Sprague-Dawley rats, aged 20 months, weighing 650-700 g, were divided into 4 groups ( n=15 each) using a random number table method: control group (group C), POCD group (group P), edaravone group (group E) and ERK inhibitor group (group I). The rats received laparotomy under 3% sevoflurane anesthesia to prepare POCD model in P, E and I groups. Edaravone 3 mg/kg was intraperitoneally injected at 30 min before operation in E and I groups, ERK inhibitor PD98059 0.3 mg/kg was injected via the tail vein in group I. The open field test was performed at 3 days after operation to evaluate the spontaneous activity of rats, then Morris water maze test was performed to evaluate the cognitive function of rats on 3-7 days after operation. The rats were sacrificed after the end of Morris water maze test, and hippocampal tissues were obtained for determination of the expression of phosphorylated ERK (p-ERK), phosphorylated CREB (p-CREB), synaptophysin and postsynaptic density protein 95 (PSD-95) (by Western blot) and dendrite length and density of dendrites in hippocampal CA1 area (using Golgi staining). Results:Compared with group C, the escape latency was significantly prolonged after operation, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was down-regulated, and the dendritic length and density of hippocampal neurons were reduced in group P ( P<0.05). Compared with group P, the escape latency was significantly shortened, the number of crossing the original platform was increased, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was up-regulated, and the dendritic length and density of hippocampal neurons were increased in group E ( P<0.05). Compared with group E, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was down-regulated, the dendritic length of hippocampal neurons was shortened, and the density of hippocampal neurons was decreased in group I( P<0.05). Conclusions:The mechanism by which edaravone improves POCD may be related to activating ERK/CREB signaling pathway and changing synaptic plasticity in hippocampal CA1 region in aged rats.

Effect of sleep fragmentation on postoperative cognitive dysfunction and hippocampal glutamatergic metabolism in aged mice anesthetized with isoflurane / 中华麻醉学杂志

Objective:To evaluate the effect of sleep fragmentation on postoperative cognitive dysfunction (POCD) and hippocampal glutaminergic metabolism in aged mice anesthetized with isoflurane.Methods:Forty healthy SPF-grade male C57BL/6J mice, aged 18 months, weighing 20-30 g, were divided into 4 groups ( n= 10 each) by the random number table method: normal control group (group C), sleep fragmentation group (group SF), isoflurane anesthesia/surgery group (group I/S), and sleep fragmentation plus isoflurane anesthesia/surgery group (group SF+ I/S). Group C did not received any treatment. Group SF received sleep fragmentation for 24 h. The right carotid artery exposure was performed under isoflurane anesthesia in group I/S. Group SF+ I/S received isoflurane anesthesia/right carotid artery exposure at 24 h after sleep fragmentation. The metabolic levels of glutamate (Glu), glutamine (Gln), Glu/Gln complex (Glx), and N-acetylaspartate (NAA) and their ratio to creatine (Cr) were measured by in vivo 9.4T hydrogen proton magnetic resonance spectroscopy at 2 h after anaesthesia. Y maze and Morris water maze tests were used to evaluate the cognitive function at 1-7 days after surgery. The mice were sacrificed after the behavioral testing, brain tissues were immediately obtained, and the number of Nissl bodies and density of dendritic spines in the hippocampal CA1 region were measured by Nissl staining and Golgi staining, respectively. Results:Compared with group C, the percentage of exploration time and shuttle times at the novel arm were significantly decreased, the number of crossing the original platform was decreased, the time of stay at the target quadrant was shortened, the ratios of Glu/Cr, Gln/Cr and Glx/Cr in the hippocampal CA1 region were increased, and the ratio of NAA/Cr was decreased, and the number of Nissl bodies and density of dendritic spines were decreased in SF, I/S and SF+ I/S groups ( P<0.05). Compared with group SF and group I/S, the percentage of exploration time and shuttle times at the novel arm were significantly decreased, the number of crossing the original platform was decreased, the time of stay at the target quadrant was shortened, the ratios of Glu/Cr and Glx/Cr in hippocampal CA1 region was increased, the ratio of NAA/Cr was decreased, and the number of Nissl bodies and density of dendritic spines were decreased in group SF+ I/S ( P<0.05). Conclusions:Sleep fragmentation exacerbates POCD in aged mice anesthetized with isoflurane, and the mechanism is related to nerve injury induced by abnormality in hippocampal glutaminergic metabolism excitability.

Role of orphan nuclear receptor Nur77 in tunicamycin-induced injury to hippocampal neurons of mice: relationship with endoplasmic reticulum stress / 中华麻醉学杂志

Objective:To evaluate the role of orphan nuclear receptor Nur77 in tunicamycin(TM)-induced injury to hippocampal neurons and the relationship with endoplasmic reticulum stress in mice.Methods:Mouse HT22 cells were divided into 4 groups ( n=10 each) using a random number table method: control group (C group), Nur77 specific agonist Csn-B group (Csn-B group), endoplasmic reticulum stress inducer TM group (TM group), and TM+ Csn-B group. Cells in C group were cultured for 24 h under normal condition. In Csn-B group, Csn-B at a final concentration of 10 μg/ml was added to the culture medium, and the cells were incubated for 24 h. In TM group, TM at a final concentration of 200 ng/ml was added to the culture medium and the cells were incubated for 24 h to induce cell endoplasmic reticulum stress injury. Cells in TM+ Csn-B group were pretreated with Csn-B at a final concentration of 10 μg/ml for 15 min, then TM at a final concentration of 200 ng/ml was added, and the cells were co-incubated for 24 h. The cell viability was examined by CCK-8 assay kit after treatment in each group. The expression of endoplasmic reticulum stress-related protein CCAAT/enhancer-binding protein homologous protein (CHOP), glucose regulated protein 78 (GRP78)and apoptosis-associated protein Bcl-2, Bax, caspase-3 and cleaved-caspase-3 was detected by Western blot. Results:Compared with C group, the cell viability was significantly decreased, and the expression of CHOP, GRP78, Bax and cleaved-caspase-3 was up-regulated, and the expression of Bcl-2 and caspase-3 was down-regulated in TM group ( P<0.05 or 0.01). Compared with TM group, the cell viability was significantly increased, the expression of CHOP, GRP78, Bax and cleaved-caspase-3 was down-regulated, and the expression of Bcl-2 and caspase-3 was up-regulated in TM+ Csn-B group ( P<0.05 or 0.01). Conclusions:Orphan nuclear receptor Nur77 is involved in TM-induced injury to hippocampal neurons, which is related to activation of the endoplasmic reticulum stress in mice.

Effect of electroacupuncture on calcium homeostasis in hippocampal neurons of mice with sepsis-associated encephalopathy / 中华麻醉学杂志

Objective:To investigate the effect of electroacupuncture on calcium homeostasis in hippocampal neurons of mice with sepsis-associated encephalopathy (SAE).Methods:Twenty-four healthy male C57BL/6J mice, weighing 18-22 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (Sham group), SAE group, SAE plus electroacupuncture group (SAE+ EA group), and SAE plus sham electroacupuncture group (SAE+ SEA group). The virus carrying calcium ion (Ca 2+ ) fluorescent probes was injected and then an optical fiber was implanted into the hippocampal CA1 area to record the fluorescence signals of Ca 2+ . SAE was induced by cecal ligation and puncture in anesthetized mice at 3 weeks after administration. Starting from 3 days before surgery, Baihui and bilateral Quchi and bilateral Zusanli acupoints were stimulated for 30 min per day for 7 consecutive days in SAE+ EA group. In SAE+ SEA group, electroacupuncture was performed at the points 0.2 mm lateral to the corresponding acupoints without electrical stimulation. Open field tests were conducted at 5 days after surgery to record the number of rearing and changes in related Ca 2+ signals in hippocampal CA1 neurons. Novel object recognition tests were conducted at 6-7 days after surgery to record the recognition time and changes in related Ca 2+ signals in hippocampal CA1 neurons. Mice were sacrificed after the end of behavioral testing on 7 days after surgery, and brain tissues ipsilateral to the optical fiber implant were obtained and the fluorescence intensity of Ca 2+ in the hippocampal CA1 neurons was acquired using a fluorescent microscope. Results:Compared with Sham group, the number of rearing and amplitudes of related Ca 2+ signals in hippocampal CA1 neurons while rearing were significantly decreased in SAE group and SAE+ SEA group ( P<0.05), and no statistically significant changes were found in the parameters mentioned above in SAE+ EA group ( P>0.05), and the recognition index and amplitudes of related Ca 2+ signals while recognizing were significantly deceased, and the fluorescence intensity of Ca 2+ in hippocampal CA1 neurons was increased in SAE, SAE+ EA and SAE+ SEA groups ( P<0.05). Compared with SAE group and SAE+ SEA group, the number of rearing and amplitudes of related Ca 2+ signals in hippocampal CA1 neurons while rearing were significantly increased, the recognition index and amplitudes of related Ca 2+ signals in hippocampal CA1 neurons while recognizing were increased, and the fluorescence intensity of Ca 2+ in hippocampal CA1 neurons was decreased in SAE+ EA group ( P<0.05). There were no statistically significant differences in the parameters mentioned above between SAE group and SAE+ SEA group ( P>0.05). Conclusions:The mechanism by which electroacupuncture alleviates SAE may be related to regulation of Ca 2+ homeostasis in hippocampal neurons of mice.

Effect of surgery under propofol anesthesia during mid-pregnancy on cognitive function and hippocampal HDAC2-CREB-NR2B signaling pathway in offspring rats / 中华麻醉学杂志

Objective:To evaluate the effect of surgery under propofol anesthesia during mid-pregnancy on the cognitive function and hippocampal histone deacetylase 2 (HDAC2)-cAMP response element-binding protein (CREB)-N-methyl-D-aspartate (NMDA) receptor 2B subunit (NR2B)-containing NMDA receptor (NR2B) signaling pathway in the offspring rats.Methods:Thirty healthy Sprague-Dawley rats at 14 days of gestation were divided into 3 groups ( n=10 each) using a random number table method: propofol anesthesia group (P group), surgery under propofol anesthesia group (S group) and control group (C group). In S group, propofol 20 mg/kg was injected via the caudal vein, and then propofol was continuously infused at a rate of 20 mg·kg -1·h -1 to maintain anesthesia for 4 h, and exploratory laparotomy was performed. Group P received no exploratory laparotomy and the other treatments were similar to those previously described in group S. The equal volume of normal saline was given instead in group C. The learning and memory of the offspring rats was assessed using Morris water maze test on postnatal day 30. The expression of HDAC2, phosphorylated CREB (p-CREB), NR2B, brain-derived neurotriphic factor (BDNF) and phosphorylated tyrosine kinase B (p-TrkB) in offspring′s hippocampi was evaluated by Western blot. Apoptosis in hippocampal neurons was detected by TUNEL staining. Results:Compared with group C, the escape latency was significantly prolonged, the frequency of crossing the original platform was decreased, the time spent in the second quadrant was shortened, the expression of HDAC2 was up-regulated, the expression of p-CREB, NR2B, BDNF and p-TrkB was down-regulated, and the apoptosis rate of the hippocampal neurons was increased in P and S groups ( P<0.05). Compared with P group, the escape latency was significantly prolonged, the frequency of crossing the original platform was decreased, the time spent in the second quadrant was shortened, the expression of HDAC2 was up-regulated, the expression of p-CREB, NR2B, BDNF and p-TrkB was down-regulated, and the apoptosis rate of the hippocampal neurons was increased in S group ( P<0.05). Conclusions:Surgery under propofol anesthesia during mid-pregnancy can decrease the cognitive function of offspring rats, and the mechanism is related to the regulation of HDAC2-CREB-NR2B signaling pathway and the promotion of apoptosis in hippocampal neurons.