Theta Oscillations Support Prefrontal-hippocampal Interactions in Sequential Working Memory / 神经科学通报·英文版

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.

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

HDAC2 Inhibits Hippocampal Neurogenesis and Impairs the Cognitive Function in Prenatally Stressed Adult Offspring / HDAC2 Inhibe la Neurogénesis del Hipocampo y Afecta la Función Cognitiva en la Descendencia Adulta Estresada Prenatalmente

SUMMARY: The objective of this study was to investigate the mechanism of prenatal stress on the cognitive function of offspring, and clarify the change of histone deacetylase 2 (HDAC2) expression in hippocampal neurons of offspring. 16 pregnant SD rats were randomly divided into control group and stress group, with eight rats in each group. The stress group received restrained stress from 15 to 21 days of pregnancy, while the control group did not receive any treatment. Anxiety-like behavior and spatial memory, learning and memory ability were detected in open field, elevated plus maze, novel object recognition test, and Barnes maze. Nissl staining was used to detect the function of hippocampal neurons. Western blot was used to detect the expression of HDAC2 protein in hippocampal neurons of adult offspring. Immunofluorescence staining was used to detect the expression of HDAC2 protein and hippocampal neurogenesis. The learning and memory ability of adult offspring was decreased. The prenatal stress damaged the function of hippocampal neurons , the expression of HDAC2 was down-regulated, and the number of neurons was reduced. Maternal prenatal stress can down- regulate the expression of HDAC2 in the hippocampus of offspring, inhibits hippocampal neurogenesis and impairs the cognitive function.

El objetivo de este estudio fue investigar el mecanismo del estrés prenatal en la función cognitiva de la descendencia y aclarar el cambio de la expresión de la histona desacetilasa 2 (HDAC2) en las neuronas del hipocampo de la descendencia. 16 ratas SD preñadas se dividieron aleatoriamente en un grupo de control y un grupo de estrés, con ocho ratas en cada grupo. El grupo de estrés recibió estrés durante 15 a 21 días de pre, preñez, mientras que el grupo de control no recibió ningún tratamiento. El comportamiento similar a la ansiedad y la memoria espacial, el aprendizaje y la capacidad de memoria se detectaron en campo abierto, laberinto en cruz elevado, prueba de reconocimiento de objetos novedosos y laberinto de Barnes. La tinción de Nissl se utilizó para detectar la función de las neuronas del hipocampo. Se utilizó Western blot para detectar la expresión de la proteína HDAC2 en las neuronas del hipocampo de la descendencia adulta. La tinción de inmunofluorescencia se utilizó para detectar la expresión de la proteína HDAC2 y la neurogénesis del hipocampo. La capacidad de aprendizaje y memoria de la descendencia adulta se redujo. El estrés prenatal dañó la función de las neuronas del hipocampo, se reguló negativamente la expresión de HDAC2 y se redujo el número de neuronas. El estrés prenatal materno puede regular a la baja la expresión de HDAC2 en el hipocampo de la descendencia, inhibe la neurogénesis del hipocampo y deteriora la función cognitiva.

A psicopatia e o criminoso nato: a modernização do positivismo criminológico / Psychopathy and the born criminal: the modernization of criminological positivism / Psicopatía y el criminal nato: la modernización del positivismo criminológico

O conceito de psicopatia é habitualmente associado a uma psicopatologia caracterizada pela falta de empatia, manipulação, agressividade, impulsividade, egocentrismo, crueldade e criminalidade. Já amplamente aceito pela comunidade científica, o conceito costuma ser utilizado em contextos jurídico-penais na validação de seu funcionamento punitivo. Dentre as concepções que alicerçaram o surgimento histórico desse conceito, destaca-se o papel do criminoso nato de Lombroso. Nesse sentido, este estudo buscou evidenciar como o conceito contemporâneo de psicopatia se firma enquanto modernização das concepções lombrosianas acerca do criminoso nato. Para isso, nos apoiamos na psicopatolologia para realizar um estudo comparativo entre as produções de Lombroso e as pesquisas contemporâneas acerca da psicopatia. Dentre as principais similaridades, destacamos a ênfase atribuída à suposta natureza criminal, etiologicamente decorrente de sua configuração orgânica. No mais, tais concepções também se assemelham no destaque de um déficit afetivo e moral, assim como na descrição da tendência a ser canhoto, egoísta, mentiroso, resistente à dor, narcisista, impulsivo, promíscuo, cruel, maléfico e inapto ao trabalho. Assim como fez Lombroso, as pesquisas acerca da psicopatia costumam ser realizadas com sujeitos já previamente criminalizados; condicionando uma seletividade étnico-racial e de classe. Descritos como sujeitos perigosos, incuráveis e intratáveis, ambas as concepções promovem a defesa do acirramento da punição jurídico-penal. Concluímos que a criminalidade nata de Lombroso continua a ser expressa no conceito de psicopatia, visto que as funções jurídico-penais e socioeconômicas de sua definição exercem o mesmo papel na legitimação científica da violência de Estado, encarceramento em massa e racismo estrutural.(AU)

Psychopathy is usually associated with a psychopathology characterized by a lack of empathy, manipulation, aggressiveness, impulsivity, egocentrism, cruelty, and criminality. Widely accepted by the scientific community, this concept is often used in legal and criminal contexts to validate its punitive functioning. Among the conceptions that underpinned the historical emergence of psychopathy, Lombroso's born criminal stands out. Hence, this study analyzes how the contemporary concept of psychopathy updates Lombrosian conceptions about the born criminal. To do so, we rely on psychopathology to conduct a comparative study between Lombroso's work and contemporary research on psychopathy. Among the main similarities, we highlight the emphasis given to the supposed criminal nature, etiologically arising from its organic configuration. Moreover, such conceptions emphasize an affective and moral deficit, and describe a tendency toward left-handedness, selfishness, lying, pain-resistance, narcissism, impulsivity, promiscuousness, cruelty, maliciousness and unfitness for work. As did Lombroso, research on psychopathy is usually conducted with individuals who have already been criminalized, conditioning an ethnic-racial and class selectivity. By describing these subjects as dangerous, incurable and intractable, both conceptions advocate for increased legal and penal punishment. In conclusion, Lombroso's natural criminality continues to underpin the concept of psychopathy, since its legal-criminal and socioeconomic functions play the same role in scientifically legitimizing state violence, mass incarceration, and structural racism.(AU)

La psicopatía es un concepto generalmente asociado a una psicopatología que se caracteriza por la falta de empatía, la manipulación, agresividad, impulsividad, egocentrismo, crueldad y criminalidad. Ya ampliamente aceptado por la comunidad científica, este concepto se utiliza a menudo en contextos legales para validar su funcionamiento punitivo. Entre los conceptos que fundamentaron el surgimiento histórico de este concepto, destaca el papel del criminal nato de Lombroso. En este contexto, este estudio buscó mostrar cómo el concepto contemporáneo de psicopatía se establece como la modernización de las concepciones lombrosianas sobre el criminal nato. Para eso, se utiliza la psicopatología para realizar un estudio comparativo entre las producciones de Lombroso y la investigación contemporánea sobre psicopatía. Entre las principales similitudes, destaca el énfasis atribuido a su supuesta naturaleza criminal, resultado etiológico de su configuración orgánica. Además, estas concepciones también son similares al resaltar un déficit afectivo y moral, así como al describir la tendencia a ser zurdo, egoísta, mentiroso, resistente al dolor, narcisista, impulsivo, promiscuo, cruel, malévolo e inadecuado para el trabajo. Como hizo Lombroso, los estudios sobre psicopatía se suelen realizar con sujetos que ya han sido criminalizados; condicionando una selectividad étnica, racial y de clase. Calificados como sujetos peligrosos, incurables e intratables, ambas concepciones promueven la defensa del aumento de la pena legal. Se concluye que la criminalidad nata de Lombroso continúa expresándose en el concepto de psicopatía, ya que las funciones penales y socioeconómicas de su definición juegan el mismo papel en la legitimación científica de la violencia estatal, encarcelamiento masivo y racismo estructural.(AU)

Formononetin improves cognitive behavior in aging rats with chronic unpredictable mild in hippocampal tissue stress by blocking the NF-κB pathway and inhibiting the release of inflammatory factors / 细胞与分子免疫学杂志

Objective To investigate the effects of formononetin (FMN) on cognitive behavior and inflammation in aging rats with chronic unpredictable mild stress (CUMS). Methods SD rats aged about 70 weeks were divided into healthy control group, CUMS model group, CUMS combined with 10 mg/kg FMN group, CUMS combined with 20 mg/kg FMN group and CUMS combined with 1.8 mg/kg fluoxetine hydrochloride (Flu) group. Except for healthy control group, other groups were stimulated with CUMS and administered drugs for 28 days. Sugar water preference, forced swimming experiment and open field experiment were used to observe the emotional behavior of rats in each group. HE staining was used to observe the pathological injury degree of brain equine area. The contents of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were detected by the kit. The apoptosis was tested by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) in the brain tissue. The levels of tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS) and interleukin 6 (IL-6) in peripheral blood were measured by ELISA. Western blot analysis was used to detect Bcl2, Bcl2 associated X protein (BAX), cleaved caspase-9, cleaved caspase-3, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and phosphorylated nuclear factor κB p65 (p-NF-κB p65) in brain tissues. Results Compared with CUMS model group, sugar water consumption, open field activity time, open field travel distance and swimming activity time significantly increased in the CUMS combined with 20 mg/kg FMN group and the CUMS combined with 1.8 mg/kg Flu group. The number of new outarm entry increased significantly, while the number of initial arm entry and other arm entry decreased significantly. The pathological damage of brain equine area was alleviated, and the contents of 5-HT and 5-HIAA were significantly increased. The ratio of BAX/Bcl2 and the expression of cleaved caspase-9 and cleaved caspase-3 protein as well as the number of apoptotic cells were significantly decreased. The contents of TNF-α, iNOS and IL-6 were significantly decreased. The protein levels of TLR4, MyD88 and p-NF-κB p65 were significantly decreased. Conclusion FMN can inhibit the release of inflammatory factors by blocking NF-κB pathway and improve cognitive and behavioral ability of CUMS aged rats.

Resveratrol improves cognitive function in severely burned rats by inhibiting hippocampal NF-κB/JNK pathway / 细胞与分子免疫学杂志

Objective To investigate the protective effect of resveratrol (RSV) on improving cognitive function in severely burned rats and its possible mechanism. Methods 18 male SD rats aged 18-20 months were randomly divided into 3 groups: control group, model group and RSV group, with 6 rats in each group. After successful modeling, the rats in RSV group were gavaged once daily with RSV (20 mg/kg). Meanwhile, the rats in control group and model group were gavaged once daily with an equal volume of sodium chloride solution. After 4 weeks, the cognitive function of all rats was estimated by Step-down Test. The concentration of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) protein in serum of rats were detected by ELISA. The expression of IL-6, TNF-α mRNA and protein were estimated by real-time PCR and Western blotting. The apoptosis of hippocampal neurons was tested by terminal deoxynuclectidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). The expression of nuclear transcription factor-κB (NF-κB)/c-Jun N-terminal kinase (JNK) pathway-related proteins in hippocampus were assessed by Western blotting. Results Compared with the rats in model group, rats in RSV group exhibited improved cognitive function. Consistently, the rats in RSV group had a reduced concentration of TNF-α and IL-6 in serum, decreased mRNA and protein expressions of TNF-α and IL-6 in hippocampus, and decreased apoptosis rate and relative expression of p-NF-κB p65/NF-κB p65 and p-JNK/JNK in hippocampal neurons. Conclusion RSV alleviates inflammatory response and hippocampal neuronal apoptosis by inhibiting NF-κB/JNK pathway, thereby improving cognitive function in severely burned rats.

Therapeutic effect and mechanism of Xiaoyao Kangai Jieyu Recipe on mice with breast cancer related depression through regulating COX pathway / 中国中药杂志

This study aimed to investigate the intervention effect and mechanism of Xiaoyao Kangai Jieyu Recipe(XKJR) on hip-pocampal microglia and neuronal damage in mice with breast cancer related depression. The mouse model of breast cancer related depression was established by inoculation of 4T1 breast cancer cells in axilla and subcutaneous injection of corticosterone(30 mg·kg~(-1)). The successfully modeled mice were randomly divided into a model group, a positive drug group(capecitabine 60 mg·kg~(-1)+fluoxetine 19.5 mg·kg~(-1)), and XKJR group(19.5 mg·kg~(-1) crude drug), with 6 in each group. Another 6 normal mice were taken as a normal group. The administration groups were given corresponding drugs by gavage, while the normal and model groups were given an equal volume of distilled water, once a day for 21 consecutive days. The depressive behavior of mice was assessed by glucose consumption test, open field test and novelty-suppressed feeding test. Hematoxylin and eosin(HE) staining and tumor suppression rate were used to evaluate the changes of axillary tumors. The mRNA expressions and the relative protein expressions of interleukin-1β(IL-1β), interleukin-18(IL-18), cyclooxyganese-2(COX-2) and glutamyl-prolyl-tRNA synthetase(EPRs) in the hippocampus of mice were determined by quantitative real-time polymerase chain reaction(qRT-PCR) and immunohistochemistry, respectively. Immunofluorescence was performed to detect the mean fluorescence intensity of CD11b, a marker of hippocampal microglia activation. Nissler staining and transmission electron microscopy were employed to observe the morphological changes and the ultramorphological changes of hippocampal neurons, respectively. The experimental results indicated that compared with the normal group, the model group had reduced glucose consumption and lowered number of total activities in open field test(P<0.05, P<0.01), prolonged first feeding latency in no-velty-suppressed feeding test(P<0.01), and significant depression-like behavior; the contents of IL-1β, IL-18, COX-2, and EPRs in hippocampus were increased(P<0.05, P<0.01), with hippocampal microglia activation and obvious neuronal damage. Compared with the model group, the positive drug group and the XKJR group presented an improvement in depressive behaviors, a decrease in the contents of IL-1β, IL-18, COX-2 and EPRs in hippocampus, and an alleviation in the activation of hippocampal microglia and neuronal damage; the tumor suppression rates of positive drug and XKJR were 40.32% and 48.83%, respectively, suggesting a lower tumor growth rate than that of the model group. In summary, XKJR may improve hippocampal microglia activation and neuronal damage in mice with breast cancer related depression through activating COX signaling pathway.

Antidepressant mechanism of Shenling Kaixin Granules based on BDNF/TrkB/CREB pathway / 中国中药杂志

To investigate the antidepressant mechanism of Shenling Kaixin Granules(SLKX) in treating chronic unpredictable mild stress(CUMS) model rats. Ninety male SD rats were randomly divided into control group, model group, Shugan Jieyu Capsules(110 mg·kg~(-1)) group and SLKX low-(90 mg·kg~(-1)), medium-(180 mg·kg~(-1)), and high-dose(360 mg·kg~(-1)) groups. Depression rat model was replicated by CUMS method. After treatment, the behavioral changes of rats were evaluated by sugar preference, open field, elevated cross maze and forced swimming experiments. The contents of interleukin 1 beta(IL-1β), tumor necrosis factor α(TNF-α), brain-derived neurotrophic factor(BDNF) and 5-hydroxytryptamine(5-HT) in serum were determined by enzyme linked immunosorbent assay(ELISA), and the activities of superoxide dismutase(SOD) and catalase(CAT) in hippocampal CA1 region were also detected. Pathological changes in hippocampal CA1 region were detected by hematoxylin-eosin(HE) staining, and Western blot was used to determine the expression of nerve growth factor(NGF), BDNF, phospho-tyrosine kinase receptor(p-TrkB)/TrkB, phospho-cAMP-response element binding protein(p-CREB)/CREB, nuclear factor E2 related factor 2(Nrf2), heme oxygenase 1(HO-1), B-cell lymphoma-2(Bcl-2)/Bcl-2 associated X protein(Bax) and caspase-3 in hippocampal CA1 region. RESULTS:: showed that compared with the control group, the model group had decreased sugar preference, reduced number of entries and time spent in the center of open field and shortened total distance of movement, reduced number of entries and proportion of time spent in open arm, and increased number and time of immobility in forced swimming experiment. Additionally, the serum contents of IL-1β and TNF-α and the expression of caspase-3 were higher, while the contents of BDNF and 5-HT, the activities of SOD and CAT in hippocampal CA1 region, the expressions of NGF, BDNF, p-TrkB/TrkB, p-CREB/CREB, HO-1 and Bcl-2/Bax, and the Nrf2 nuclear translocation were lower in model group than in control group. Compared with the conditions in model group, the sugar preference, the number of entries and time spent in the center of open, total distance of movement, and the number of entries and proportion of time spent in open arm in treatment groups were increased while the number and time of immobility in forced swimming experiment were decreased; the serum contents of IL-1β and TNF-α and the expression of caspase-3 were down regulated, while the contents of BDNF and 5-HT, the activities of SOD and CAT in hippocampal CA1 region, the expressions of NGF, BDNF, p-TrkB/TrkB, p-CREB/CREB, HO-1, Bcl-2/Bax, and Nrf2 nuclear translocation were enhanced. In conclusion, SLKX might regulate the Nrf2 nucleus translocation by activating BDNF/TrkB/CREB pathway, lower oxidative stress damage in hippocampus, inhibit caspase-3 activity, and reduce apoptosis of hippocampal nerve cells, thereby playing an antidepressant role.

Effects of post-traumatic stress disorder on the excitability of glutamatergic and GABAergic neurons in dorsal and ventral hippocampus in mice / 生理学报

The purpose of this study was to investigate the effects of post-traumatic stress disorder (PTSD) on electrophysiological characteristics of glutamatergic and GABAergic neurons in dorsal hippocampus (dHPC) and ventral hippocampus (vHPC) in mice, and to elucidate the mechanisms underlying the plasticity of hippocampal neurons and memory regulation after PTSD. Male C57Thy1-YFP/GAD67-GFP mice were randomly divided into PTSD group and control group. Unavoidable foot shock (FS) was applied to establish PTSD model. The spatial learning ability was explored by water maze test, and the changes in electrophysiological characteristics of glutamatergic and GABAergic neurons in dHPC and vHPC were examined using whole-cell recording method. The results showed that FS significantly reduced the movement speed, and enhanced the number and percentage of freezing. PTSD significantly prolonged the escape latency in localization avoidance training, shortened the swimming time in the original quadrant, extended the swimming time in the contralateral quadrant, and increased absolute refractory period, energy barrier and inter-spike interval of glutamatergic neurons in dHPC and GABAergic neurons in vHPC, while decreased absolute refractory period, energy barrier and inter-spike interval of GABAergic neurons in dHPC and glutamatergic neurons in vHPC. These results suggest that PTSD can damage spatial perception of mice, down-regulate the excitability of dHPC and up-regulate the excitability of vHPC, and the underlying mechanism may involve the regulation of spatial memory by the plasticity of neurons in dHPC and vHPC.

Progress in application of adult endogenous neurogenesis in brain injury repair / 生理学报

Persistent neurogenesis exists in the subventricular zone (SVZ) of the ventricles and the subgranular zone (SGZ) of the dentate gyrus of the hippocampus in the adult mammalian brain. Adult endogenous neurogenesis not only plays an important role in the normal brain function, but also has important significance in the repair and treatment of brain injury or brain diseases. This article reviews the process of adult endogenous neurogenesis and its application in the repair of traumatic brain injury (TBI) or ischemic stroke, and discusses the strategies of activating adult endogenous neurogenesis to repair brain injury and its practical significance in promoting functional recovery after brain injury.

Effects of Yizhi Tiaoshen acupuncture on learning and memory function and the expression of phosphorylated tau protein in the hippocampus of Alzheimer's disease model rats / 中国针灸

OBJECTIVE@#To observe the effects of Yizhi Tiaoshen (benefiting mental health and regulating the spirit) acupuncture on learning and memory function, and the expression of phosphorylated tubulin-associated unit (tau) protein in the hippocampus of Alzheimer's disease (AD) model rats, and explore the effect mechanism of this therapy on AD.@*METHODS@#A blank group and a sham-operation group were randomly selected from 60 male SD rats, 10 rats in each one. AD models were established in the rest 40 rats by the intraperitoneal injection of D-galactose and okadaic acid in the CA1 region of the bilateral hippocampus. Thirty successfully-replicated model rats were randomly divided into a model group, a western medication group and an acupuncture group, 10 rats in each one. In the acupuncture group, acupuncture was applied to "Baihui" (GV 20), "Sishencong" (EX-HN 1), "Neiguan" (PC 6), "Shenmen" (HT 7), "Xuanzhong" (GB 39) and "Sanyinjiao" (SP 6); and the needles were retained for 10 min. Acupuncture was given once daily. One course of treatment was composed of 6 days, with the interval of 1 day; the completion of treatment included 4 courses. In the western medication group, donepezil hydrochloride solution (0.45 mg/kg) was administrated intragastrically, once daily; it took 7 days to accomplish one course of treatment and a completion of intervention was composed of 4 courses. Morris water maze (MWM) and novel object recognition test (NORT) were used to assess the learning and memory function of the rats. Using HE staining and Nissl staining, the morphological structure of the hippocampus was observed. With Western blot adopted, the protein expression of the tau, phosphorylated tau protein at Ser198 (p-tau Ser198), protein phosphatase 2A (PP2A) and glycogen synthase kinase-3β (GSK-3β) in the hippocampus was detected.@*RESULTS@#There were no statistical differences in all of the indexes between the sham-operation group and the blank group. Compared with the sham-operation group, in the model group, the MWM escape latency was prolonged (P<0.05), the crossing frequency and the quadrant stay time in original platform were shortened (P<0.05), and the NORT discrimination index (DI) was reduced (P<0.05); the hippocampal cell numbers were declined and the cells arranged irregularly, the hippocampal neuronal structure was abnormal and the numbers of Nissl bodies decreased; the protein expression of p-tau Ser198 and GSK-3βwas increased (P<0.05) and that of PP2A decreased (P<0.05). When compared with the model group, in the western medication group and the acupuncture group, the MWM escape latency was shortened (P<0.05), the crossing frequency and the quadrant stay time in original platform were increased (P<0.05), and DI got higher (P<0.05); the hippocampal cell numbers were elevated and the cells arranged regularly, the damage of hippocampal neuronal structure was attenuated and the numbers of Nissl bodies were increased; the protein expression of p-tau Ser198 and GSK-3β was reduced (P<0.05) and that of PP2A was increased (P<0.05). There were no statistically significant differences in the above indexes between the acupuncture group and the western medication group (P>0.05).@*CONCLUSION@#Acupuncture therapy of "benefiting mental health and regulating the spirit" could improve the learning and memory function and alleviate neuronal injure of AD model rats. The effect mechanism of this therapy may be related to the down-regulation of GSK-3β and the up-regulation of PP2A in the hippocampus, and then to inducing the inhibition of tau protein phosphorylation.

Effects of electroacupuncture on rats with cognitive impairment: An iTRAQ-based proteomics analysis / 中西医结合学报

OBJECTIVE@#The study explores the effects of electroacupuncture (EA) at the governing vessel (GV) on proteomic changes in the hippocampus of rats with cognitive impairment.@*METHODS@#Healthy male rats were randomly divided into 3 groups: sham, model and EA. Cognitive impairment was induced by left middle cerebral artery occlusion in the model and EA groups. Rats in the EA group were treated with EA at Shenting (GV24) and Baihui (GV20) for 7 d. Neurological deficit was scored using the Longa scale, the learning and memory ability was detected using the Morris water maze (MWM) test, and the proteomic profiling in the hippocampus was analyzed using protein-labeling technology based on the isobaric tag for relative and absolute quantitation (iTRAQ). The Western blot (WB) analysis was used to detect the proteins and validate the results of iTRAQ.@*RESULTS@#Compared with the model group, the neurological deficit score was significantly reduced, and the escape latency in the MWM test was significantly shortened, while the number of platform crossings increased in the EA group. A total of 2872 proteins were identified by iTRAQ. Differentially expressed proteins (DEPs) were identified between different groups: 92 proteins were upregulated and 103 were downregulated in the model group compared with the sham group, while 142 proteins were upregulated and 126 were downregulated in the EA group compared with the model group. Most of the DEPs were involved in oxidative phosphorylation, glycolipid metabolism and synaptic transmission. Furthermore, we also verified 4 DEPs using WB technology. Although the WB results were not exactly the same as the iTRAQ results, the expression trends of the DEPs were consistent. The upregulation of heat-shock protein β1 (Hspb1) was the highest in the EA group compared to the model group.@*CONCLUSION@#EA can effect proteomic changes in the hippocampus of rats with cognitive impairment. Hspb1 may be involved in the molecular mechanism by which acupuncture improves cognitive impairment.

Neural Correlates of Spatial Navigation in Primate Hippocampus / 神经科学通报·英文版

The hippocampus has been extensively implicated in spatial navigation in rodents and more recently in bats. Numerous studies have revealed that various kinds of spatial information are encoded across hippocampal regions. In contrast, investigations of spatial behavioral correlates in the primate hippocampus are scarce and have been mostly limited to head-restrained subjects during virtual navigation. However, recent advances made in freely-moving primates suggest marked differences in spatial representations from rodents, albeit some similarities. Here, we review empirical studies examining the neural correlates of spatial navigation in the primate (including human) hippocampus at the levels of local field potentials and single units. The lower frequency theta oscillations are often intermittent. Single neuron responses are highly mixed and task-dependent. We also discuss neuronal selectivity in the eye and head coordinates. Finally, we propose that future studies should focus on investigating both intrinsic and extrinsic population activity and examining spatial coding properties in large-scale hippocampal-neocortical networks across tasks.

Contextual Fear Learning and Extinction in the Primary Visual Cortex of Mice / 神经科学通报·英文版

Fear memory contextualization is critical for selecting adaptive behavior to survive. Contextual fear conditioning (CFC) is a classical model for elucidating related underlying neuronal circuits. The primary visual cortex (V1) is the primary cortical region for contextual visual inputs, but its role in CFC is poorly understood. Here, our experiments demonstrated that bilateral inactivation of V1 in mice impaired CFC retrieval, and both CFC learning and extinction increased the turnover rate of axonal boutons in V1. The frequency of neuronal Ca2+ activity decreased after CFC learning, while CFC extinction reversed the decrease and raised it to the naïve level. Contrary to control mice, the frequency of neuronal Ca2+ activity increased after CFC learning in microglia-depleted mice and was maintained after CFC extinction, indicating that microglial depletion alters CFC learning and the frequency response pattern of extinction-induced Ca2+ activity. These findings reveal a critical role of microglia in neocortical information processing in V1, and suggest potential approaches for cellular-based manipulation of acquired fear memory.

Zuogui Jiangtang Jieyu Decoction promotes neural stem cell self-renewal and activates Shh signaling in the hippocampal dentate gyrus of diabetic rats with depression / 南方医科大学学报

OBJECTIVE@#To investigate the effect of Zuogui Jiangtang Jieyu Decoction (ZJJ) on Shh signaling and self-renewal of neural stem cells in the hippocampal dentate gyrus of diabetic rats with depression.@*METHODS@#Diabetic rat models with depression were randomly divided into model group, positive drug (metformin + fluoxetine) group, and low-, medium-, and high-dose ZJJ groups (n=16), with normal SD rats as the control group. The positive drugs and ZJJ were administered by gavage, and the rats in the control and model groups were given distilled water. After the treatment, blood glucose level was detected using test strips, and behavioral changes of the rats were assessed by forced swimming test and water maze test. ELISA was used to examine the serum level of leptin; The expressions of nestin and Brdu proteins in the dentate gyrus of the rats were detected using immunofluorescence assay, and the expressions of self-renewal marker proteins and Shh signaling proteins were detected using Western blotting.@*RESULTS@#The diabetic rats with depression showed significantly increased levels of blood glucose and leptin (P < 0.01) and prolonged immobility time in forced swimming test (P < 0.01) and increased stage climbing time with reduced stage seeking time and stage crossings in water maze test (P < 0.01). The expressions of nestin and Brdu in the dentate gyrus, the expressions of cyclin D1, SOX2, Shh, Ptch1, Smo in the hippocampus and the nuclear expression of Gli-1 were decreased (P < 0.01) while hippocampal Gli-3 expression was increased significantly (P < 0.01) in the rat models. Treatment of rat models with high-dose ZJJ significantly reduced the blood glucose (P < 0.01) and leptin level (P < 0.05) and improved their performance in behavioral tests (P < 0.01). The treatment also obviously increased the expressions of nestin, Brdu, cyclin D1, SOX2, Shh, Ptch1, and Smo and the nuclear expression of Gli-1 in the dentate gyrus (P < 0.01) and reduced hippocampal expression of Gli-3 (P < 0.05) in the rat models.@*CONCLUSION@#ZJJ can significantly improve the self-renewal ability of neural stem cells and activate Shh signaling in dentate gyrus of diabetic rats with depression.

Study on effects of 40 Hz light flicker stimulation on spatial working memory in rats and its neural mechanism / 生物医学工程学杂志

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment, with the predominant clinical diagnosis of spatial working memory (SWM) deficiency, which seriously affects the physical and mental health of patients. However, the current pharmacological therapies have unsatisfactory cure rates and other problems, so non-pharmacological physical therapies have gradually received widespread attention. Recently, a novel treatment using 40 Hz light flicker stimulation (40 Hz-LFS) to rescue the cognitive function of model animals with AD has made initial progress, but the neurophysiological mechanism remains unclear. Therefore, this paper will explore the potential neural mechanisms underlying the modulation of SWM by 40 Hz-LFS based on cross-frequency coupling (CFC). Ten adult Wistar rats were first subjected to acute LFS at frequencies of 20, 40, and 60 Hz. The entrainment effect of LFS with different frequency on neural oscillations in the hippocampus (HPC) and medial prefrontal cortex (mPFC) was analyzed. The results showed that acute 40 Hz-LFS was able to develop strong entrainment and significantly modulate the oscillation power of the low-frequency gamma (lγ) rhythms. The rats were then randomly divided into experimental and control groups of 5 rats each for a long-term 40 Hz-LFS (7 d). Their SWM function was assessed by a T-maze task, and the CFC changes in the HPC-mPFC circuit were analyzed by phase-amplitude coupling (PAC). The results showed that the behavioral performance of the experimental group was improved and the PAC of θ-lγ rhythm was enhanced, and the difference was statistically significant. The results of this paper suggested that the long-term 40 Hz-LFS effectively improved SWM function in rats, which may be attributed to its enhanced communication of different rhythmic oscillations in the relevant neural circuits. It is expected that the study in this paper will build a foundation for further research on the mechanism of 40 Hz-LFS to improve cognitive function and promote its clinical application in the future.

Mechanism of Jiaotai Pills in treatment of depression based on quantitative proteomics / 中国中药杂志

This study aimed to investigate the effect of Jiaotai Pills on protein expression in the hippocampus of the rat model of chronic unpredictable mild stress(CUMS)-induced depression by quantitative proteomics and explore the anti-depression mechanism of Jiaotai Pills. The SD rats were randomized into control, model, Jiaotai Pills, and fluoxetine groups(n=8). Other groups except the control group were subjected to CUMS modeling for 4 weeks. After 4 weeks of continuous administration, the changes of behavior and pathological morphology of the hippocampal tissue were observed. Proteins were extracted from the hippocampal tissue, and bioinformatics analysis was performed for the differentially expressed proteins(DEPs) identified by quantitative proteomics. Western blot was employed to verify the key DEPs. The results showed that Jiaotai Pills significantly alleviated the depression behaviors and hippocampal histopathological changes in the rat model of CUMS-induced depression. A total of 5 412 proteins were identified in the hippocampus of rats, including 65 DEPs between the control group and the model group and 35 DEPs between the Jiaotai Pills group and the model group. There were 16 DEPs with the same trend in the Jiaotai Pills group and the control group, which were mainly involved in sphingolipid, AMPK, and dopaminergic synapse signaling pathways. The Western blot results of Ppp2r2b, Cers1, and Ndufv3 in the hippocampus were consistent with the results of proteomics. In conclusion, Jiaotai Pills may play an anti-depression role by modulating the levels of Ppp2r2b, Cers1, Ndufv3 and other proteins and regulating sphingolipid, AMPK, and dopaminergic synapse signaling pathways.

Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats / 中国中药杂志

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

Xixin Decoction improves learning and memory ability of SAMP8 by enhancing neuroprotective effect and inhibiting neuroinflammation / 中国中药杂志

This study aimed to explore the possible effect of Xixin Decoction(XXD) on the learning and memory ability of Alzheimer's disease(AD) model senescence-accelerated mouse-prone 8(SAMP8) and the related mechanism in enhancing neuroprotective effect and reducing neuroinflammation. Forty SAMP8 were randomly divided into a model group(10 mL·kg~(-1)·d~(-1)), a probiotics group(0.39 g·kg~(-1)·d~(-1)), a high-dose group of XXD granules(H-XXD, 5.07 g·kg~(-1)·d~(-1)), a medium-dose group of XXD granules(M-XXD, 2.535 g·kg~(-1)·d~(-1)), and a low-dose group of XXD granules(L-XXD, 1.267 5 g·kg~(-1)·d~(-1)). Eight senescence-accelerated mouse-resistant 1(SAMR1) of the same age and strain were assigned to the control group(10 mL·kg~(-1)·d~(-1)). After ten weeks of intragastric administration, the Morris water maze was used to test the changes in spatial learning and memory ability of mice after treatment. Meanwhile, immunofluorescence staining was used to detect the positive expression of receptor for advanced glycation end products(AGER), Toll-like receptor 1(TLR1), and Toll-like receptor 2(TLR2) in the hippocampal CA1 region of mice. Western blot was employed to test the protein expression levels of silencing information regulator 2 related enzyme 1(SIRT1), AGER, TLR1, and TLR2 in the hippocampus of mice. Enzyme linked immunosorbent assay(ELISA) was applied to assess the levels of Aβ_(1-42) in the hippocampus of mice and the levels of nuclear factor κB p65(NF-κB p65), NOD-like receptor protein 3(NLRP3), tumor necrosis factor-α(TNF-α), and interleukin-1β(IL-1β) in the serum and hippocampus of mice. Compared with the model group, XXD significantly improved the spatial learning and memory ability of SAMP8, increased the expression of neuroprotective factors in the hippocampus, decreased the levels of neuroinflammatory factors, and inhibited the expression of Aβ_(1-42). In particular, H-XXD significantly increased the expression of SIRT1 in the hippocampus of mice, reduced the expression levels of NF-κB p65, NLRP3, TNF-α, and IL-1β in the serum and hippocampus of mice, and decreased the expression of AGER, TLR1, and TLR2 in the hippocampus of mice(P<0.05 or P<0.01). XXD may improve the spatial learning and memory ability of AD model SAMP8 by enhancing the neuroprotective effect and inhibiting neuroinflammation.