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1.
Article in Chinese | WPRIM | ID: wpr-1016443

ABSTRACT

ObjectiveTo investigate the effects of Lactobacillus rhamnosus GG (LGG)on microglia and Tau phosphorylation in the hippocampus of aged mice induced by anesthesia and surgery. MethodsA total of thirty 18-month-old C57BL/6J mice were randomly divided into three groups: control group, anesthesia surgery group, and anesthesia surgery + LGG group (10 mice/group). The aged mice were oral administered by NS or LGG 109 CFU 150 μL once a day for 20 days. Then anesthesia surgery group and anesthesia surgery +LGG group received anesthesia with isoflurane and exploratory laparotomy. The activation status of microglia in the hippocampus was detected by immunofluorescence staining 12 hours after surgery. IL-6 concentration changes was detected by ELISA. The expression changes of Tau protein phosphorylation site (Tau-pS202/pT205) and total Tau protein was detected by western blot. ResultsThe microglia in the hippocampus of the control group were in a resting state, and the concentration of inflammatory factor IL-6 was (82.08 ± 12.07) pg/mL in control group. Compared to the control group, the anesthesia surgery group showed microglial cell Microglia were activated, the concentration of inflammatory factors IL-6 increased significantly to (123.7±5.72) pg/mL (P=0.000), and the expression of phosphorylated Tau-pS202/pT205 increased the hippocampus (P=0.002). Compared to the anesthesia surgery group, the activated microglia were inhibited, the concentration of IL-6 decreased to (96.68±9.59) pg/mL (P=0.008), and the expression of phosphorylated Tau-pS202/pT205 reduced significantly in the AS+LGG group (P=0.002). While there were no significant changes in total Tau protein among 3 groups. ConclusionPreoperative administration of probiotic LGG can alleviate the activation of microglia, increased secretion of inflammatory factors, and increased Tau protein phosphorylation levels in the hippocampus of elderly mice caused by anesthesia surgery.

2.
Article in Chinese | WPRIM | ID: wpr-1012690

ABSTRACT

ObjectiveTo investigate the effects of epigallocatechin-3-gallate (EGCG) on learning and memory abilities of amygdala electrical kindling-induced epilepsy in rats and its mechanism. MethodMale SD rats were randomly divided into the normal group, model group, intervention group (model+25 mg·kg-1 EGCG), and EGCG group (25 mg·kg-1 EGCG). Rats in the EGCG group were only given EGCG intraperitoneal injection, those in the normal group were only given electrode implantation, and those in the other experimental groups were given amygdala electrical kindling stimulation to establish a chronic kindling epilepsy model. EGCG was injected intraperitoneally daily before electrical stimulation. Twenty-four hours after the last electrical stimulation, the escape latency and percentage of target quadrant were recorded by the Morris water maze. Twenty-four hours after the behavioral test, rats in each group were sacrificed by decapitation. The number of hippocampal neurons was observed by Nissl staining. The thickness of postsynaptic density in the hippocampus, synaptic cleft, length of active zone and the curvature of synaptic interface were observed by transmission electron microscopy (TEM). The expressions of synapse-related proteins synaptotagmin (Syt), postsynaptic density-95 (PSD-95) and Kalirin-7 in the hippocampus were examined by Western blot. ResultCompared with those in the normal group, the escape latency was significantly prolonged (P<0.05, P<0.01) and the target quadrant ratio was significantly decreased in the model group (P<0.05). The number of hippocampus neurons decreased significantly (P<0.01). The synaptic cleft of the hippocampus was widened significantly, and the length of active zone and the thickness of postsynaptic density were significantly decreased (P<0.05, P<0.01). The expressions of synapse-related proteins Syt, PSD-95 and Kalirin-7 in the hippocampus were significantly decreased (P<0.05,P<0.01). Compared with those in the model group, the escape latency was significantly shortened and the percentage of target quadrant was significantly increased in the intervention group (P<0.05, P<0,01). The number of hippocampal neurons significantly increased (P<0.01). The synaptic cleft of the hippocampus was significantly shortened, and the length of active zone and postsynaptic density were significantly increased (P<0.05, P<0.01). The expressions of synaptic related proteins Syt, PSD-95 and Kalirin-7 were significantly increased (P<0.05, P<0.01). ConclusionEGCG can effectively improve cognitive dysfunction after epilepsy. Its protective effect may be achieved by protecting the ultrastructure of hippocampal synapses and regulating the expressions of synapse-related proteins Syt, PSD-95 and Kalirin-7.

3.
Neuroscience Bulletin ; (6): 147-156, 2024.
Article in English | WPRIM | ID: wpr-1010679

ABSTRACT

The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation. This stereoelectroencephalography (SEEG) study investigated how the dorsolateral prefrontal cortex (DLPFC) interacts with the hippocampus in the online processing of sequential information. Twenty patients with epilepsy (eight women, age 27.6 ± 8.2 years) completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus. Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise (random trials) than to maintain ordered lines (ordered trials) before recalling the orientation of a particular line. First, the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC (3-10 Hz). In particular, the hippocampal theta power increase correlated with the memory precision of line orientation. Second, theta phase coherences between the DLPFC and hippocampus were enhanced for ordering, especially for more precisely memorized lines. Third, the theta band DLPFC → hippocampus influence was selectively enhanced for ordering, especially for more precisely memorized lines. This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.


Subject(s)
Adult , Female , Humans , Young Adult , Male , Epilepsy , Hippocampus , Memory, Short-Term , Mental Recall , Prefrontal Cortex , Theta Rhythm
4.
Article in English | WPRIM | ID: wpr-1010595

ABSTRACT

5-Hydroxytryptamine (5-HT) type 3 receptor (5-HT3R) is the only type of ligand-gated ion channel in the 5-HT receptor family. Through the high permeability of Na+, K+, and Ca2+ and activation of subsequent voltage-gated calcium channels (VGCCs), 5-HT3R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system (CNS). 5-HT3Rs are widely expressed in the medial prefrontal cortex (mPFC), amygdala (AMYG), hippocampus (HIP), periaqueductal gray (PAG), and other brain regions closely associated with anxiety reactions. They have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions. 5-HT3Rs mediate the activation of the cholecystokinin (CCK) system in the AMYG, and the γ‍-aminobutyric acid (GABA) "disinhibition" mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons (IINs). In contrast, a 5-HT3R-induced GABA "disinhibition" mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects. 5-HT2R-mediated regulation of anxiety reactions are also activated by 5-HT3R-activated 5-HT release in the HIP and PAG. This provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT3Rs. However, given the circuit specific modulation of 5-HT3Rs on emotion, systemic use of 5-HT3R agonism or antagonism alone seems unlikely to remedy anxiety, which deeply hinders the current clinical application of 5-HT3R drugs. Therefore, the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.


Subject(s)
Serotonin , Receptors, Serotonin, 5-HT3 , Anxiety , Neurons , gamma-Aminobutyric Acid
5.
Article in Chinese | WPRIM | ID: wpr-1006554

ABSTRACT

ObjectiveTo explore the mechanism of Wenyang Jieyu prescription in regulating hippocampal neuron apoptosis and improving synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 (PD0) were randomly assigned into a control group (n=10) and a modeling group (n=50). Maternal separation combined with restraint stress was adopted to establish the mouse model of depression, and the modeled mice were randomized into model, Wenyang prescription, Jieyu prescription, Wenyang Jieyu prescription, and fluoxetine groups (n=10) on the weaning day (PD21). From PD21 to PD111, the mice were fed with the diets mixed with corresponding medicines. The sucrose preference test, open field test, O-maze test, and novel object recognition test were then conducted to evaluate the depression, memory, and learning abilities of mice. Immunohistochemistry (IHC) was employed to measure the atomic absorbance (AA) of postsynaptic density protein 95 (PSD95) in the hippocampus. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling (TUNEL) was employed to detect the apoptosis of hippocampal neurons. Western blot was employed to determine the protein levels of brain-derived neurotrophic factor (BDNF), phosphorylated tyrosine kinase receptor B/tyrosine kinase receptor B (p-TrkB/TrkB), phosphorylated protein kinase B/protein kinase B (p-Akt/Akt), phosphorylated mammalian target of rapamycin/mammalian target of rapamycin (p-mTOR/mTOR), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), cysteinyl aspartate-specific proteinase-3 (Caspase-3), synaptophysin (Syn), and PSD95. ResultCompared with the control group, the modeling decreased the sucrose preference rate, time spent in central zone within 5 min, total movement distance, time spent in the open arm, and cognition index (P<0.01). Furthermore, it decreased the expression of PSD95, increased the neuron apoptosis in the hippocampus (P<0.01), down-regulated the protein levels of BDNF, p-TrkB/TrkB, p-Akt/Akt, p-mTOR/mTOR, Bcl-2, PSD95, and Syn (P<0.01), and up-regulated the protein levels of Bax and Caspase-3 (P<0.05) in the hippocampus. Compared with the model group, Wenyang Jieyu prescription and fluoxetine increased the sucrose preference rate, time spent in central zone within 5 min, total movement distance, time spent in the open arm, and cognition index (P<0.05, P<0.01). Moreover, the drugs increased the expression of PSD95, reduced the neuron apoptosis (P<0.01), up-regulated the protein levels of BDNF, p-TrkB/TrkB, p-Akt/Akt, p-mTOR/mTOR, Bcl-2, PSD95, and Syn (P<0.01), and down-regulated the protein levels of Bax and Caspase-3 (P<0.01). ConclusionWenyang Jieyu prescription outperformed Wenyang prescription and Jieyu prescription in the treatment of the depressive behavior induced by maternal separation combined with restraint stress in mice. It exerted the therapeutic effect by reducing the hippocampal neuron apoptosis and improving the synaptic plasticity via the BDNF/Akt/mTOR pathway.

6.
Article in Chinese | WPRIM | ID: wpr-1006267

ABSTRACT

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.

7.
Dement. neuropsychol ; 18: e20230015, 2024. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1557680

ABSTRACT

ABSTRACT. The immediate early gene exhibits activation markers in the nervous system consisting of ARC, EGR-1, and c-Fos and is related to synaptic plasticity, especially in the hippocampus. Immediate early gene expression is affected by physical exercise, which induces direct ARC, EGR-1, and c-Fos expression. Objective: To assess the impact of exercise, we conducted a literature study to determine the expression levels of immediate early genes (ARC, c-Fos, and EGR-1). Methods: The databases accessed for online literature included PubMed-Medline, Scopus, and ScienceDirect. The original English articles were selected using the following keywords in the title: (Exercise OR physical activity) AND (c-Fos) AND (Hippocampus), (Exercise OR physical activity) AND (ARC) AND (Hippocampus), (Exercise OR physical activity) AND (EGR-1 OR zif268) AND (Hippocampus). Results: Physical exercise can affect the expression of EGR-1, c-Fos, and ARC in the hippocampus, an important part of the brain involved in learning and memory. High-intensity physical exercise can increase c-Fos expression, indicating neural activation. Furthermore, the expression of the ARC gene also increases due to physical exercise. ARC is a gene that plays a role in synaptic plasticity and regulation of learning and memory, changes in synaptic structure and increased synaptic connections, while EGR-1 also plays a role in synaptic plasticity, a genetic change that affects learning and memory. Overall, exercise or regular physical exercise can increase the expression of ARC, c-Fos, and EGR-1 in the hippocampus. This reflects the changes in neuroplasticity and synaptic plasticity that occur in response to physical activity. These changes can improve cognitive function, learning, and memory. Conclusion: c-Fos, EGR-1, and ARC expression increases in hippocampal neurons after exercise, enhancing synaptic plasticity and neurogenesis associated with learning and memory.


RESUMO. O gene precoce imediato (GPI) exibe marcadores de ativação no sistema nervoso constituídos por ARC, EGR-1 e c-Fos e está relacionado à plasticidade sináptica, especialmente no hipocampo. A expressão do GPI é afetada pelo exercício físico, que induz a expressão direta de ARC, EGR-1 e c-Fos. Objetivo: Para avaliar o impacto do exercício físico, realizamos um estudo de literatura para determinar os níveis de expressão dos GPIs (ARC, c-Fos e EGR-1). Métodos: A base de dados utiliza literatura on-line, PubMed-Medline, Scopus e ScienceDirect. O artigo original em inglês usa as seguintes palavras-chave em seu título: (Exercise) AND (c-Fos) AND (Hippocampus), (Exercise) AND (ARC) AND (Hippocampus), (Exercise) AND (EGR-1) AND (Hippocampus). Resultados: O exercício físico pode afetar a expressão de EGR-1, c-fos e ARC no hipocampo, uma parte importante do cérebro envolvida na aprendizagem e na memória. O exercício físico aumenta a expressão do gene c-Fos; sua alta intensidade pode aumentar a expressão de c-Fos, indicando ativação neural. Além disso, a expressão do gene ARC aumentou devido ao exercício físico, onde ARC é um gene que desempenha um papel na plasticidade sináptica e na regulação da aprendizagem e da memória, nas mudanças na estrutura sináptica e no aumento das conexões sinápticas, enquanto o EGR-1 também desempenha um papel na plasticidade sináptica, uma mudança genética que afeta o aprendizado e a memória. De maneira geral, o exercício físico regular pode aumentar a expressão de ARC, c-fos e EGR-1 no hipocampo. Isso reflete as mudanças na neuroplasticidade e na plasticidade sináptica que ocorrem em resposta à atividade física. Essas mudanças podem melhorar a função cognitiva, o aprendizado e a memória. Conclusão: A expressão de c-Fos, EGR-1 e ARC aumenta após o exercício físico nos neurônios do hipocampo, para aumentar a plasticidade sináptica, a neurogênese associada ao aprendizado e à memória.

8.
Rev. argent. radiol ; 87(4): 149-154, dic. 2023. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1529632

ABSTRACT

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.

9.
Acta neurol. colomb ; 39(3)sept. 2023.
Article in Spanish | LILACS | ID: biblio-1533500

ABSTRACT

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


Subject(s)
Anterior Thalamic Nuclei , Intralaminar Thalamic Nuclei , Epilepsy, Temporal Lobe , Vagus Nerve Stimulation , Electric Stimulation , Hippocampus
10.
Acta neurol. colomb ; 39(3)sept. 2023.
Article in Spanish | LILACS | ID: biblio-1533501

ABSTRACT

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.


Subject(s)
Smell , Temporal Lobe , Piriform Cortex , Hippocampus , Epilepsies, Partial
11.
Article | IMSEAR | ID: sea-225633

ABSTRACT

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.

12.
Arq. neuropsiquiatr ; 81(5): 492-501, May 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1447401

ABSTRACT

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.

13.
Acta Anatomica Sinica ; (6): 375-382, 2023.
Article in Chinese | WPRIM | ID: wpr-1015200

ABSTRACT

Objective To investigate the effect and mechanism of astrocytes on the proliferation of neural stem cells (NSCs) in adult and juvenile hippocampus microenvironment. Methods Hippocampal astrocytes were isolated and cultured from 5 female SD rats at day 1 and week 30 postnatal, respectively; Embryonic hippocampus NSCs was isolated and cultured from 1 SD rat at day 15 of gestation; Conditioned astrocyte culture medium(CM) was collected for NSCs culture; Flow cytometry and CCK-8 were used to detect the proliferation of NSCs cultured in CM. Colony stimulating factor 1 (CSF-1) with differential expression was screened by mass spectrometry after cultured astrocyte CM. Western blotting and ELISA were used to verify the result of mass spectrometry. Immunofluorescence, flow cytometry and CCK-8 were used to detect the proliferation of NSCs treated with different concentrations of CSF-1 recombinant protein (20 μg/ L, 100 μg/ L, 1 mg/ L and 5 mg/ L). Results Compared with the adult group, the CM of hippocampal astrocytes in the young group could promote the proliferation of NSCs(P<0. 01); Compared with the conditioned medium of hippocampal astrocytes in the juvenile group, the expression of CSF-1 in the hippocampus of the elder group was significantly up-regulated(P<0. 01); At 20 μg/ L, CSF-1 promoted the proliferation of NSCs(P<0. 01), and 5 mg/ L CSF-1 inhibited significantly the proliferation of NSCs(P<0. 01). Conclusion The secretion of CSF-1 by astrocytes in hippocampal microenvironment can regulate the proliferation of NSCs with the development of the times.

14.
Acta Anatomica Sinica ; (6): 689-694, 2023.
Article in Chinese | WPRIM | ID: wpr-1015175

ABSTRACT

Objective To observe the potential mechanism of electroacupuncture regulating the erythropoietin-producing hepatocellular receptor B2/erythropoietin-producing hepatocellular receptor-interacting B2/big mitogen-activated protein kinase 1(EphB2/EphrinB2/BMK1) signaling pathway to improve neural damage in vascular dementia rats. Methods Eighty SD male adult rats were randomly divided into a sham surgery group, a model group, a non acupoint electroacupuncture group, a nimodipine group, and an electroacupuncture three needle group. The vascular dementia rat model was made by the modified Pulsinelli four vessel occlusion method. After grouping, the rats in each group were subjected to water maze test, HE staining, Nissl staining, and transmission electron microscopy(TEM) to observe the pathological changes in the hippocampal CA1 area, and the expression of EphB2 and BMK1 in the hippocampal CA1 area was detected by immunohistochemistry; Detection of EphB2 and BMK1 protein expression in rat hippocampal CA1 region was detected by Western blotting. Results Compared with the model group, the escape latency of vascular dementia rats treated with electroacupuncture and nimodipine decreased (P0.05). Compared with the nimodipine group, the expression of EphB2 and BMK1 in the hippocampal CA1 region of rats in the electroacupuncture Zhisanzhen group significantly increased (P<0.05). Conclusion Electroacupuncture may improve the damage of hippocampal neurons in vascular dementia rats by increasing the expression of EphB2 and BMK1 in the CA1 region of the hippocampus, thereby improving the learning and memory of vascular dementia rats.

15.
Acta Anatomica Sinica ; (6): 620-627, 2023.
Article in Chinese | WPRIM | ID: wpr-1015163

ABSTRACT

[Abstract] Objective To elucidate the important role of Nogo-A in climacteric neurodegeneration such as memory impairment by observing memory function and the expression of Nogo-A in hippocampus and striatum of rats under low estrogen condition. Methods Fouthy-five female SD rats were divided into sham operation group, ovariectomized group and ovariectomized estrogen treatment group with 15 rats in each group. Medication was given 2 weeks after ovariectomized. Estrogen treatment group was subcutaneously injected in groin with estrogen [25 μg/ (kg.d)] dissolved in sterile sesame oil. The sham operation group and the ovariectomized group were given the same amount of aseptic sesame oil. Samples were collected after 6 weeks of drug treatment. The difference of memory function of rats in three groups was observed by conditioned fear training experiment, and the expression of Nogo-A in hippocampus and striatum was observed by immunohistochemistry and Western blotting. Results Compared with the sham and estrogen treatment group, memory function in ovariectomized group decreased significantly and the number of Nogo-A positive neurons in hippocampus and striatum of ovariectomized rats was significantly higher than that of sham operation group (P 0. 05). The result of immunoblotting was consistent with the above-mentioned immunohistochemical result. Conclusion The increased expression of Nogo-A in hippocampus and striatum under low estrogen condition may be one of the key reasons for memory impairment in climacteric women.

16.
Chinese Pharmacological Bulletin ; (12): 380-386, 2023.
Article in Chinese | WPRIM | ID: wpr-1013866

ABSTRACT

Aim To investigate the effects of total saponins from Trillium tschonoskii maxim(TST)on cognitive impairment and mitochondrial autophagy in aging rats induced by D-galactose(D-gal). Methods Male SD rats were randomly divided into normal control group,model group(D-gal,subcutaneous injection),intervention group(TST,low,medium and high dose groups by intragastric administration),with 10 rats in each group,and administered for 6 weeks. Morris water maze was used to evaluate the cognitive function. HE and Nissl staining were used to test the hippocampal and brain cortex morphology. Immunohistochemistry staining was applied to detect the localization expression of Pink1 and Parkin. Western blot was employed to detect the expressions of Pink1,Parkin,LC3-Ⅱ,p62 and Beclin1. Results Compared with the normal control group,the escape latency time was prolonged and the number of crossing platform decreased in D-gal model group(P<0.05). The number of neurons in hippocampus significantly decreased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly decreased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 were markedly reduced,while the expression of p62 was significantly raised(P<0.05). Compared with D-gal model group,the escape latency time of TST dose groups was shortened,the Times of crossing the platform was more,and the time of staying in the platform quadrant increased(P<0.05). The number of neurons in hippocampus significantly increased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly increased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 in hippocampus were apparently up-regulated,while the protein expression of p62 was evidently down-regulated(P<0.05). Conclusions TST has neuroprotective effects on the learning and memory capacities in aging rats induced by D-gal,which may be related to the increasing levels of Pink1,Parkin,LC3-Ⅱ and Beclin1 proteins and the activation of mitochondrial autophagy.

17.
Chinese Pharmacological Bulletin ; (12): 315-325, 2023.
Article in Chinese | WPRIM | ID: wpr-1013859

ABSTRACT

Aim To observe the effect of thalidomide on the learning and memory ability and hippocampal tissue proteome of Alzheimer's disease(AD)mice,to screen the differential proteins of thalidomide in preventing and treating AD,the pathways involved in regulation,and to explore its possible mechanism. Methods The experimental mice were randomly divided into blank control group,model group,and thalidomide high and low dose groups. The drugs were administered by gavage every day for 21 days. After the administration,Morris water maze test was used to evaluate the learning and memory abilities of the mice,HE staining and Nissl staining were used to observe the pathological tissue morphology of the mouse hippocampus,ELISA was employed to detect the mitochondrial respiratory chain enzyme complex in mouse brain,and the Label-free proteomics method was used to screen different groups of hippocampal proteome proteins. Results The results of the Morris water maze showed that compared with the model group,the escape latency time of the drug group was significantly reduced,and the number of crossing the platform significantly increased(P<0.05). Thalidomide administration could improve the morphological structure of neurons in hippocampus,and could increase the activity of the mitochondrial respiratory chain complex ,Ⅱ, and of the brain tissues of AD mice(P<0.05). A total of 4 378 differential proteins were identified,which had a significant regulatory effect on the expression of 580 proteins in hippocampus of AD mice(P<0.05). Energy metabolism may jointly participate in the regulation of neurodegeneration pathways-changes in pathways such as various diseases and Alzheimer's disease. Conclusions Thalidomide can significantly improve the learning and memory function of AD model mice induced by Aβ

18.
Chinese Pharmacological Bulletin ; (12): 1073-1077, 2023.
Article in Chinese | WPRIM | ID: wpr-1013783

ABSTRACT

Aim To investigate the effect of astaxanthin (ASTA) on the blood brain barrier (BBB) injury and cognitive disorders in mice induced by hyperglycemia and the possible mechanism. Methods db/db mice aged eight weeks were administered ASTA (5, 10, 20 mg • kg

19.
Chinese Pharmacological Bulletin ; (12): 1787-1793, 2023.
Article in Chinese | WPRIM | ID: wpr-1013723

ABSTRACT

Aim To explore the inhibitory effect of Buyang Huanwu Decoction on the inflammatory response in the hippocampus of brain tissues of CIRI rats by regulating SIRT1 and the underlying mechanism. Methods The middle cerebral artery embolization (MCAO) model was prepared in rats and divided into sham operation group (Sham), model group (MCAO/R), Buyang Huanwu Decoction group (BYHWT),and BYHWT + SIRT1 inhibitor group (BYHWT + EX527). Zea Longa was used to detect the neurological function score of rats in each group; TTC staining was used to determine the volume of cerebral infarction; HE staining was used to observe the pathological damage of the hippocampus; Western blot was used to detect the expression levels of SIRT1 and IL-6; immunohistochemistry was used to detect TNF-α, IL-1β expression level. Results Compared with the sham group,the neurological function score of the MCAO/R group increased (P < 0.05); the volume of cerebral infarction increased (P < 0.05); the nerve cells in hippocampus were severely damaged, arranged disorderly, and the nucleus was broken; Western blot showed that the expression of SIRT1 decreased, IL-6 expression increased (P <0.05); immunohistochemistry showed that TNF-α,IL-1β expression increased (P < 0.05). Compared with the MCAO/R group, the neurological function score of the BYHWT group decreased (P <0.05); the volume of cerebral infarction decreased (P < 0.05); the damage of nerve cells in hippocampus was reduced; Western blot showed that the expression of SIRT1 increased and IL-6 expression decreased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression decreased (P < 0.05). Compared with the BYHWT group, the neurological function score of the BYHWT + EX527 group increased (P < 0.05); the volume of cerebral infarction was raised (P <0.05); the damage of nerve cells in hippocampus was aggravated; Western blot showed that the expression of SIRT1 decreased and IL-6 expression increased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression increased (P < 0.05). Conclusions Preliminary discussion of Buyang Huanwu Decoction can activate SIRT1 in hippocampus of rat brain tissues to reduce the inflammatory response after CIRI and play a role in brain protection.

20.
Acta Pharmaceutica Sinica B ; (6): 3708-3727, 2023.
Article in English | WPRIM | ID: wpr-1011150

ABSTRACT

The formation of learning and memory is regulated by synaptic plasticity in hippocampal neurons. Here we explored how gestational exposure to dexamethasone, a synthetic glucocorticoid commonly used in clinical practice, has lasting effects on offspring's learning and memory. Adult offspring rats of prenatal dexamethasone exposure (PDE) displayed significant impairments in novelty recognition and spatial learning memory, with some phenotypes maintained transgenerationally. PDE impaired synaptic transmission of hippocampal excitatory neurons in offspring of F1 to F3 generations, and abnormalities of neurotransmitters and receptors would impair synaptic plasticity and lead to impaired learning and memory, but these changes failed to carry over to offspring of F5 and F7 generations. Mechanistically, altered hippocampal miR-133a-3p-SIRT1-CDK5-NR2B signaling axis in PDE multigeneration caused inhibition of excitatory synaptic transmission, which might be related to oocyte-specific high expression and transmission of miR-133a-3p. Together, PDE affects hippocampal excitatory synaptic transmission, with lasting consequences across generations, and CDK5 in offspring's peripheral blood might be used as an early-warning marker for fetal-originated learning and memory impairment.

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