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.
Adult ; Female ; Humans ; Young Adult ; Epilepsy ; Hippocampus ; Memory, Short-Term ; Mental Recall ; Prefrontal Cortex ; Theta Rhythm ; Male

Epilepsy is a clinical syndrome caused by highly synchronized abnormal discharges of brain neurons due to various causes. Studies have shown that abnormal hippocampal neurogenesis is observed in both human epilepsy patients and animal models of epilepsy， and abnormal neurogenesis can alter normal neural circuits in the hippocampus and promote the development of hippocampal sclerosis， ultimately leading to the development and progression of epilepsy. The low-pressure hypoxic environment unique to the plateau affects hippocampal neurogenesis by regulating hypoxia-inducible factors， the Wnt signaling pathway， the Notch signaling pathway， and EPO， thereby affecting the susceptibility to epilepsy and the development and progression of epilepsy. This article reviews the mechanism of interaction between hippocampal neurogenesis and epilepsy in high-altitude hypoxic environments， in order to provide potential strategies and targets for the treatment of epilepsy.
Neurogenesis ; Hippocampus

OBJECTIVES: To analyze the effect of acupuncture at the acupoints for Yizhi Tiaoshen (benefiting the intelligence and regulating the spirit) on the functional connectivity between the hippocampus and the whole brain in the patients with Alzheimer's disease (AD), and reveal the brain function mechanism of acupuncture in treatment of AD using resting state functional magnetic resonance imaging (rs-fMRI). METHODS: Sixty patients with mild to moderate AD were randomly divided into an acupuncture + medication group (30 cases, 3 cases dropped out) and a western medication group (30 cases, 2 cases dropped out). In the western medication group, the donepezil hydrochloride tablets were administered orally, 2.5 mg to 5 mg each time, once daily; and adjusted to be 10 mg each time after 4 weeks of medication. Besides the therapy as the western medication group, in the acupuncture + medication group, acupuncture was supplemented at the acupoints for Yizhi Tiaoshen, i.e. Baihui (GV 20), Sishencong (EX-HN 1), and bilateral Shenmen (HT 7), Neiguan (PC 6), Zusanli (ST 36), Sanyinjiao (SP 6) and Xuanzhong (GB 39). The needles were retained for 30 min in one treatment, once daily; and 6 treatments were required weekly. The duration of treatment was 6 weeks in each group. The general cognitive function was assessed by the mini-mental state examination (MMSE) and Alzheimer's disease assessment scale-cognitive part (ADAS-Cog) before and after treatment in the two groups. Using the rs-fMRI, the changes in the functional connectivity (FC) of the left hippocampus and the whole brain before and after treatment were analyzed in the patients of the two groups (11 cases in the acupuncture + medication group and 12 cases in the western medication group). RESULTS: After treatment, compared with those before treatment, MMSE scores increased and ADAS-Cog scores decreased in the two groups (P<0.05); MMSE score was higher, while the ADAS-Cog score was lower in the acupuncture + medication group when compared with those in the western medication group (P≤0.05). After treatment, in the western medication group, FC of the left hippocampus was enhanced with the left fusiform gyrus, the inferior frontal gyrus of the left triangular region, the bilateral superior temporal gyrus and the right superior parietal gyrus (P<0.05), while FC was weakened with the left inferior temporal gyrus, the left middle frontal gyrus and the right dorsolateral superior frontal gyrus when compared with that before treatment (P<0.05). After treatment, in the acupuncture + medication group, FC of the left hippocampus was increased with the right gyrus rectus, the left inferior occipital gyrus, the right superior temporal gyrus and the left middle occipital gyrus (P<0.05), and it was declined with the left thalamus (P<0.05) when compared with those before treatment. After treatment, in the acupuncture + medication group, FC of the left hippocampus was strengthened with the bilateral inferior temporal gyrus, the bilateral middle temporal gyrus, the right gyrus rectus, the bilateral superior occipital gyrus, the left lenticular nucleus putamen, the left calcarine fissure and surrounding cortex, the inferior frontal gyrus of the left insulae operculum, the left medial superior frontal gyrus and the right posterior central gyrus (P<0.05) compared with that of the western medication group. CONCLUSIONS Acupuncture at the acupoints for Yizhi Tiaoshen improves the cognitive function of AD patients, and its main brain functional mechanism is related to intensifying the functional connectivity of the left hippocampus with the default network (inferior temporal gyrus, middle temporal gyrus and superior frontal gyrus, gyrus rectus), as well as with the sensory (posterior central gyrus) and visual (calcarine fissure and surrounding cortex and superior occipital gyrus) brain regions.
Humans ; Acupuncture Points ; Alzheimer Disease/therapy* ; Magnetic Resonance Imaging ; Brain/physiology* ; Acupuncture Therapy ; Hippocampus/diagnostic imaging*

BACKGROUND: Posttraumatic stress disorder (PTSD) and depression are highly comorbid. Psilocybin exerts substantial therapeutic effects on depression by promoting neuroplasticity. Fear extinction is a key process in the mechanism of first-line exposure-based therapies for PTSD. We hypothesized that psilocybin would facilitate fear extinction by promoting hippocampal neuroplasticity. METHODS: First, we assessed the effects of psilocybin on percentage of freezing time in an auditory cued fear conditioning (FC) and fear extinction paradigm in mice. Psilocybin was administered 30 min before extinction training. Fear extinction testing was performed on the first day; fear extinction retrieval and fear renewal were tested on the sixth and seventh days, respectively. Furthermore, we verified the effect of psilocybin on hippocampal neuroplasticity using Golgi staining for the dendritic complexity and spine density, Western blotting for the protein levels of brain derived neurotrophic factor (BDNF) and mechanistic target of rapamycin (mTOR), and immunofluorescence staining for the numbers of doublecortin (DCX)- and bromodeoxyuridine (BrdU)-positive cells. RESULTS: A single dose of psilocybin (2.5 mg/kg, i.p.) reduced the increase in the percentage of freezing time induced by FC at 24 h, 6th day and 7th day after administration. In terms of structural neuroplasticity, psilocybin rescued the decrease in hippocampal dendritic complexity and spine density induced by FC; in terms of neuroplasticity related proteins, psilocybin rescued the decrease in the protein levels of hippocampal BDNF and mTOR induced by FC; in terms of neurogenesis, psilocybin rescued the decrease in the numbers of DCX- and BrdU-positive cells in the hippocampal dentate gyrus induced by FC. CONCLUSIONS A single dose of psilocybin facilitated rapid and sustained fear extinction; this effect might be partially mediated by the promotion of hippocampal neuroplasticity. This study indicates that psilocybin may be a useful adjunct to exposure-based therapies for PTSD and other mental disorders characterized by failure of fear extinction.
Humans ; Mice ; Animals ; Psilocybin/metabolism* ; Fear ; Extinction, Psychological ; Brain-Derived Neurotrophic Factor/metabolism* ; Bromodeoxyuridine/pharmacology* ; Hippocampus/metabolism* ; Neuronal Plasticity ; TOR Serine-Threonine Kinases/metabolism*

Obstructive sleep apnea syndrome (OSAS), a prevalent sleep disorder in children, is characterized by recurring upper airway obstruction during sleep. OSAS in children can cause intermittent hypoxia and sleep fragmentation, ultimately affect brain development and further lead to cognitive impairment if lack of timely effective intervention. In recent years, magnetic resonance imaging (MRI) and electroencephalogram (EEG) have been employed to investigate brain structure and function abnormalities in children with OSAS. Previous studies have indicated that children with OSAS showed extensive gray and white matter damage, abnormal brain function in regions such as the frontal lobe and hippocampus, as well as a significant decline in general cognitive function and executive function. However, the existing studies mainly focused on the regional activity, and the mechanism of pediatric OSAS affecting brain networks remains unknown. Moreover, it's unclear whether the alterations in brain structure and function are associated with their cognitive impairment. In this review article, we proposed two future research directions: 1) future studies should utilize the multimodal neuroimaging techniques to reveal the alterations of brain networks organization underlying pediatric OSAS; 2) further investigation is necessary to explore the relationship between brain network alteration and cognitive dysfunction in children with OSAS. With these efforts, it will be promising to identify the neuroimaging biomarkers for monitoring the brain development of children with OSAS as well as aiding its clinical diagnosis, and ultimately develop more effective strategies for intervention, diagnosis, and treatment.
Humans ; Child ; Sleep Apnea, Obstructive/complications* ; Cognition ; Hypoxia/complications* ; Hippocampus ; Frontal Lobe

Alzheimer's disease (AD) is a typical cognitive disorder with an increasing incidence in recent years. AD is also one of the main causes of disability and death of the elderly in current aging society. One of the most common symptoms of AD is spatial memory impairment, which occurs in more than 60% of patients. This memory loss is closely related to the impairment of cognitive maps in the brain. The entorhinal grid cells and the hippocampal place cells are important cellular basis for spatial memory and navigation functions in the brain. Understanding the abnormal firing pattern of these neurons and their impaired coordination to neural oscillations in transgenic rodents is crucial for identifying the therapeutic targets for AD. In this article, we review recent studies on neural activity based on transgenic rodent models of AD, with a focus on the changes in the firing characteristics of neurons and the abnormal electroencephalogram (EEG) rhythm in the entorhinal cortex and hippocampus. We also discuss potential cell-network mechanism of spatial memory disorders caused by AD, so as to provide a scientific basis for the diagnosis and treatment of AD in the future.
Animals ; Mice ; Alzheimer Disease/genetics* ; Animals, Genetically Modified ; Cognition ; Cognitive Dysfunction ; Hippocampus/physiology* ; Memory Disorders ; Mice, Transgenic ; Neurons/physiology*

OBJECTIVE: To explore whether the protein Deglycase protein 1 (DJ1) can ameliorate Alzheimer's disease (AD)-like pathology in Amyloid Precursor Protein/Presenilin 1 (APP/PS1) double transgenic mice and its possible mechanism to provide a theoretical basis for exploring the pathogenesis of AD. METHODS: Adeno-associated viral vectors (AAV) of DJ1-overexpression or DJ1-knockdown were injected into the hippocampus of 7-month-old APP/PS1 mice to construct models of overexpression or knockdown. Mice were divided into the AD model control group (MC), AAV vector control group (NC), DJ1-overexpression group (DJ1 ⁺), and DJ1-knockdown group (DJ1 ^-). After 21 days, the Morris water maze test, immunohistochemistry, immunofluorescence, and western blotting were used to evaluate the effects of DJ1 on mice. RESULTS: DJ1 ⁺ overexpression decreased the latency and increased the number of platform traversals in the water maze test. DJ1 ^- cells were cured and atrophied, and the intercellular structure was relaxed; the number of age spots and the expression of AD-related proteins were significantly increased. DJ1 ⁺ increased the protein expression of Nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), light chain 3 (LC3), phosphorylated AMPK (p-AMPK), and B cell lymphoma-2 (BCL-2), as well as the antioxidant levels of total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and Glutathione peroxidase (GSH-PX), while decreasing the levels of Kelch-like hydrates-associated protein 1 (Keap1), mammalian target of rapamycin (mTOR), p62/sequestosome1 (p62/SQSTM1), Caspase3, and malondialdehyde (MDA). CONCLUSION DJ1-overexpression can ameliorate learning, memory, and AD-like pathology in APP/PS1 mice, which may be related to the activation of the NRF2/HO-1 and AMPK/mTOR pathways by DJ1.
Animals ; Mice ; Alzheimer Disease/therapy* ; AMP-Activated Protein Kinases/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Antioxidants/metabolism* ; Disease Models, Animal ; Hippocampus/metabolism* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Mammals/metabolism* ; Mice, Inbred C57BL ; Mice, Transgenic ; NF-E2-Related Factor 2/metabolism* ; Presenilin-1/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

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.
Humans ; Neuroprotective Agents/therapeutic use* ; Sirtuin 1/metabolism* ; Toll-Like Receptor 2/metabolism* ; NF-kappa B/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Neuroinflammatory Diseases ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Toll-Like Receptor 1/metabolism* ; Alzheimer Disease/genetics* ; Hippocampus

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.
Rats ; Mice ; Animals ; Receptors, Ionotropic Glutamate/metabolism* ; Hippocampus ; Neuronal Plasticity ; Receptors, N-Methyl-D-Aspartate/genetics* ; Anxiety/genetics* ; gamma-Aminobutyric Acid

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.
Rats ; Animals ; Rats, Sprague-Dawley ; Depression/drug therapy* ; AMP-Activated Protein Kinases/metabolism* ; Proteomics ; Hippocampus ; Stress, Psychological/metabolism* ; Sphingolipids/metabolism* ; Disease Models, Animal ; Drugs, Chinese Herbal