Search Results (335)

The rhythm of epileptiform activity occurs in various brain injuries (ischemia, stroke, concussion, mechanical damage, AD, PD). The epileptiform rhythm is accompanied by periodic Ca²⁺ pulses, which are necessary for the neurotransmitter release, the repair of damaged connections between neurons, and the growth of new projections. The duration and amplitude of these pulses depend on intracellular calcium-binding proteins. The effect of the synthetic fast calcium buffer BAPTA on the epileptiform activity of neurons induced by the GABA(A)-receptor inhibitor, bicuculline, was investigated in a 14-DIV rat hippocampal culture. In the epileptiform activity mode, neurons periodically synchronously generate action potential (AP) bursts in the form of paroxysmal depolarization shift (PDS) clusters and their corresponding high-amplitude Ca²⁺ pulses. Changes in the paroxysmal activity and Ca²⁺ pulses were recorded continuously for 10–11 min as BAPTA accumulated. It was shown that during BAPTA accumulation, transformation of neuronal patch activity occurs. Moreover, GABAergic and glutamatergic neurons respond differently to the presence of calcium buffer. Experiments were performed on two populations of neurons: a population of GABAergic neurons that responded selectively to ATPA, a calcium-permeable GluK1 kainate receptor agonist, and a population of glutamatergic neurons with a large amplitude of cluster depolarization (greater than −20 mV). These neurons made up the majority of neurons. In the population of GABAergic neurons, during BAPTA accumulation, the amplitude of PDS clusters decreases, which leads to a switch from the PDS mode to the classical burst mode with an increase in the electrical activity of the neuron. In glutamatergic neurons, the duration of PDS clusters decreased during BAPTA accumulation. However, the amplitude changed little. The data obtained showed that endogenous calcium-binding proteins play a significant role in switching the epileptiform rhythm to the recovery rhythm and perform a neuroprotective function by reducing the duration of impulses in excitatory neurons and the amplitude of impulses in inhibitory neurons. Full article

Cardiopulmonary bypass (CPB) is associated with significant neurological complications, yet the mechanisms underlying brain injury remain unclear. This study investigated the role of interleukin-17A (IL-17A) in exacerbating CPB-induced neuronal apoptosis and identified vulnerable brain regions. Utilizing a rat CPB model and an oxygen–glucose deprivation/reoxygenation (OGD/R) cellular model, we demonstrated that IL-17A levels were markedly elevated in the hippocampus post-CPB, correlating with endoplasmic reticulum stress (ERS)-mediated apoptosis. Transcriptomic analysis revealed the enrichment of IL-17 signaling and apoptosis-related pathways. IL-17A-Neutralizing monoclonal antibody (mAb) and the ERS inhibitor 4-phenylbutyric acid (4-PBA) significantly attenuated neurological deficits and hippocampal neuronal damage. Mechanistically, IL-17A activated the Act1-IRE1-JNK1 axis, wherein heat shock protein 90 (Hsp90) competitively regulated Act1-IRE1 interactions. Co-immunoprecipitation confirmed the enhanced Hsp90-Act1 binding post-CPB, promoting IRE1 phosphorylation and downstream caspase-12 activation. In vitro, IL-17A exacerbated OGD/R-induced apoptosis via IRE1-JNK1 signaling, reversible by IRE1 inhibition. These findings identify the hippocampus as a key vulnerable region and delineate a novel IL-17A/Act1-IRE1-JNK1 pathway driving ERS-dependent apoptosis. Targeting IL-17A or Hsp90-mediated chaperone switching represents a promising therapeutic strategy for CPB-associated neuroprotection. This study provides critical insights into the molecular crosstalk between systemic inflammation and neuronal stress responses during cardiac surgery. Full article

Hydrogen-rich water (HRW) has shown neuroprotective effects in acute brain injury, but its role in chronic radiation-induced brain injury (RIBI) remains unclear. This study investigated the long-term efficacy of HRW in mitigating cognitive impairment and neuronal damage caused by chronic RIBI. Fifty male Sprague Dawley rats were randomly divided into five groups: control, irradiation (IR), IR with memantine, IR with HRW, and IR with combined treatment. All but the control group received 20 Gy whole-brain X-ray irradiation, followed by daily interventions for 60 days. Behavioral assessments, histopathological analyses, oxidative stress measurements, ¹⁸F-FDG PET/CT imaging, transcriptomic sequencing, RT-qPCR, Western blot, and serum ELISA were performed. HRW significantly improved anxiety-like behavior, memory, and learning performance compared to the IR group. Histological results revealed that HRW reduced neuronal swelling, degeneration, and loss and enhanced dendritic spine density and neurogenesis. PET/CT imaging showed increased hippocampal glucose uptake in the IR group, which was alleviated by HRW treatment. Transcriptomic and molecular analyses indicated that HRW modulated key genes and proteins, including CD44, CD74, SPP1, and Wnt1, potentially through the MIF, Wnt, and SPP1 signaling pathways. Serum CD44 levels were also lower in treated rats, suggesting its potential as a biomarker for chronic RIBI. These findings demonstrate that HRW can alleviate chronic RIBI by preserving neuronal structure, reducing inflammation, and enhancing neuroplasticity, supporting its potential as a therapeutic strategy for radiation-induced cognitive impairment. Full article

Alzheimer’s dementia (AD) is a disease of the ageing brain. It begins in the hippocampal region with the epicentre in the entorhinal cortex, then gradually extends into adjacent brain areas involved in memory and cognition. The events which initiate the damage are unknown and under intense investigation. Localization to the hippocampus can now be explained by anatomical features of the blood vessels supplying this region. Blood supply and hence oxygen delivery to the area are jeopardized by poor flow through narrowed arteries. In genomic and metabolomic studies, the respiratory chain and mitochondrial pathways which generate ATP were leading pathways associated with AD. This review explores the notion that ATP depletion resulting from hippocampal hypoperfusion has a prime role in initiating damage. Sections cover sensing of ATP depletion and protective responses, vulnerable processes with very heavy ATP consumption (the malate shuttle, the glutamate/glutamine/GABA (γ-aminobutyric acid) cycle, and axonal transport), phospholipid disturbances and peroxidation by reactive oxygen species, hippocampal perfusion and the effects of hypertension, chronic hypoxia, and arterial vasospasm, and an overview of recent relevant genomic studies. The findings demonstrate strong scientific arguments for the proposal with increasing supportive evidence. These lines of enquiry should be pursued. Full article

The recent identification of early-onset mutational signatures with geographic variations by Diaz-Gay et al. is a significant finding, since early-onset colorectal cancer has emerged as an alarming public health challenge in the past two decades, and the pathomechanism remains unclear. Environmental risk factors, including lifestyle and diet, are highly suspected. The identification of colibactin from Escherichia coli as a potential pathogenic source is a major step forward in addressing this public health challenge. Therefore, the following opinion manuscript aims to outline the likely onset of the pathomechanism and the critical role of acquired Piezo2 channelopathy in early-onset colorectal cancer, which skews proton availability and proton motive force regulation toward E. coli within the microbiota–host symbiotic relationship. In addition, the colibactin produced by the pks island of E. coli induces host DNA damage, which likely interacts at the level of Wnt signaling with Piezo2 channelopathy-induced pathological remodeling. This transcriptional dysregulation eventually leads to tumorigenesis of colorectal cancer. Mechanotransduction converts external physical cues to inner chemical and biological ones. Correspondingly, the proposed quantum mechanical free-energy-stimulated ultrafast proton-coupled tunneling, initiated by Piezo2, seems to be the principal and essential underlying novel oscillatory signaling that could be lost in colorectal cancer onset. Hence, Piezo2 channelopathy not only contributes to cancer initiation and impaired circadian regulation, including the proposed hippocampal ultradian clock, but also to proliferation and metastasis. Full article

Background/Objectives: There is evidence concerning herbal medicines and plant-based compounds, including Lamiaceae species, as putative senolytic agents; however, there are only a few reports on Ocimum americanum properties using rat models. The aim of this study was to investigate the neuroprotective effects and potential modes of action of Ocimum americanum L. using ex vivo and in vivo assays to assess the effects of OAEE on hippocampal tissue from young adult and late middle-aged Wistar rats, with a focus on oxidative stress, cholinesterase activity, and neuroinflammatory markers. Methods: Ocimum americanum ethanol extract (OAEE) was incubated with hippocampal slices of young adult and late middle-aged male Wistar rats exposed to H₂O₂; an acute treatment with OAEE was evaluated in aversive memory performance and neurochemical parameters, such as hippocampal cellular oxidative state, and anticholinesterase activity, and a diet supplementation of OAEE were evaluated on several hippocampal biochemical parameters, such as oxidative state, anticholinesterase activity, and neuroinflammatory parameters in young adult and late middle-aged male rats. Results: OAEE reversed the H₂O₂-induced impaired cellular viability in hippocampal slices from young adult rats, as well as protected hippocampal slices against H₂O₂-induced damage in both young adult and late middle-aged Wistar rats, indicating its neuroprotective action. Chronic dietary OAEE supplementation reduced aging-induced increases in reactive species and lipid peroxidation levels in the hippocampus. Indeed, this supplementation reduced the TNF-α content in hippocampus from both ages, and IL-1β levels in young adult rats. Conclusions: The antioxidant actions of OAEE here observed, preventing the lipoperoxidation, as well as its anti-neuroinflammatory effect, might be related to neuroprotective effect. Our findings add evidence to support the idea of the potential use of Ocimum americanum as a nutraceutical or functional food in the aging process. Full article

Age-related neurodegeneration is characterized by oxidative stress and iron-dependent cell death, yet the neuroprotective mechanisms of folic acid in modulating ferroptosis remain unclear. This study systematically investigated the role of folic acid in inhibiting ferroptosis and attenuating neuronal damage in aging, with a focus on the solute carrier family 7 member 11 (SLC7A11)-glutathione (GSH)-glutathione peroxidase 4 (GPX₄) antioxidant pathway, using aged rats supplemented with folic acid (<0.1, 2.0, and 4.0 mg/kg·diet) for 22 months, with young adult rats as controls. Brain iron accumulation and ferroptosis-related proteins (SLC7A11, GPX₄, Ferritin heavy chain 1 (FTH1)) were evaluated. In vitro, HT-22 hippocampal neuronal cells were pre-treated with folic acid (0, 10, 20 μmol/L) for 72 h before combining with Erastin (10 μmol/L)-induced ferroptosis for an additional 24 h. Intracellular Fe²⁺, lipid peroxidation (LPO), malondialdehyde (MDA), reactive oxygen species (ROS), along with cystine, GSH, and ferroptosis-related protein levels were quantified. Stable sh-SLC7A11 knockdown and control (sh-NC) cell lines were used to validate the dependency of folic acid’s protective effects on SLC7A11 expression. Folic acid supplementation in aged rats dose-dependently reduced aging-related brain iron accumulation and enhanced the expression of SLC7A11, GPX₄, and FTH1. In Erastin-induced HT-22 cells, folic acid significantly mitigated ferroptosis hallmarks. Mechanistically, folic acid increased extracellular cystine uptake and intracellular GSH synthesis, thereby activating the SLC7A11-GSH-GPX₄ antioxidant pathway. Notably, molecular docking technique suggested that compared to GPX₄, folic acid stabilized SLC7A11’s active conformation. sh-SLC7A11 knockdown completely abolished folic acid-mediated protection against ferroptosis, as evidenced by restored loss of cystine, GSH and GPX₄ production. This study innovatively emphasized the critical role of folic acid supplementation in inhibiting ferroptosis by up-regulating the SLC7A11-GSH-GPX₄ antioxidant pathway, primarily through enhancing cystine availability and SLC7A11 expression. These findings established folic acid as a potential dietary intervention for aging-related neurodegenerative diseases characterized by neuronal ferroptosis, providing preclinical evidence for folic acid based neuroprotection. Full article

Background/Objectives: Urolithin A (UA), a gut-derived metabolite of ellagitannins or ellagic acid, has recently gained attention for its potential benefits to brain health. The present research aimed to assess the antidepressant-like properties of UA in both in vitro and in vivo models and explored the molecular mechanisms underlying these effects. Methods: We investigated the antidepressant effects and mechanisms of UA in a model of corticosterone-induced damage to PC12 cells and in a model of chronic socially frustrating stress. Results: Our results demonstrate that UA treatment (5 and 10 μM) significantly alleviated cellular damage and inflammation in corticosterone (CORT)-treated PC12 cells. Furthermore, UA administration (50 and 100 mg/kg) significantly reduced immobility time in the mouse tail suspension test (TST) and forced swim test (FST), indicating its antidepressant-like activity. Additionally, treatment with UA led to the activation of the cAMP response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling cascade and triggered the activation of adenosine monophosphate-activated protein kinase (AMPK) during these processes. Importantly, pretreatment with AMPK-specific inhibitor Compound C abolished UA’s cytoprotective effects in PC12 cells, as well as its behavioral efficacy in the FST and TST, and its neurotrophic effects, highlighting the critical role of AMPK activation in mediating these effects. Furthermore, in the chronic social defeat stress (CSDS) mouse model, UA treatment (50 and 100 mg/kg) significantly alleviated depression-like behaviors, including reduced sucrose preference in the sucrose preference test, increased social avoidance behavior in the social interaction test, and anxiety-like behaviors, including diminished exploration, in the elevated plus maze test, suggesting the antidepressant-like and anxiolytic-like activities of UA. Moreover, UA treatment reversed elevated serum stress hormone levels, hippocampal inflammation, and the decreased AMPK/CREB/BDNF signaling pathway in the hippocampus of CSDS mice. Conclusions: Together, these results provide compelling evidence for UA as a viable dietary supplement or therapeutic option for managing depression. Full article

This study evaluates the effects of hypergravity (HG) on a neurodegenerative model in vitro, looking at how HG influences Tau protein aggregation in Mouse Hippocampal Neuronal Cells (HT22) induced by neurofibrillary tangle seeds. Overall, 50× g significantly, synergistically, reduced the Tau aggregate Area when combined with ERK-inhibitor PD-0325901, correlating with decreased phosphorylation at critical residues pS262 and pS396. These findings suggest HG treatments may help mitigate cytoskeletal damage linked to Tau aggregation. Full article

Neuropathic pain is a persistent and exhausting condition which results from damage to the nervous system and is often accompanied by emotional and cognitive impairments. In this study, we investigated dynamic changes in pain-related behaviors over 8 weeks using a spared nerve injury (SNI) model in male C57Bl/6 mice. We examined behavioral outcomes in conjunction with glial activation, neurogenesis, and glutamatergic signaling in the hippocampus to elucidate the mechanisms underlying cognitive and affective alterations associated with chronic pain. Our findings demonstrate that SNI-induced neuropathic pain progressively increases anxiety-like behavior and impairs both working and long-term memory. These behavioral deficits are accompanied by significant activation of microglia and astrocytes, a reduction in hippocampal neurogenesis, and a decrease in the expression of NMDA and AMPA glutamate receptor subunits and the scaffolding protein PSD-95. Taken together, our results suggest that hippocampal neuroinflammation and associated synaptic dysfunction contribute to the affective and cognitive disturbances observed in chronic pain, providing insight into potential molecular targets for therapeutic intervention. Full article

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive dysfunction and working memory impairment, with early hippocampal damage being a prominent feature. Transcranial magneto-acoustic stimulation (TMAS) has been shown to target specific brain regions for neuroregulation. Methods: This study investigated the effects of TMAS on cognitive function, working memory, and hippocampal CA3 neural rhythms in AD rats by specifically stimulating the hippocampal region. Results: The novel object recognition test and T-maze test were employed to assess behavioral performance, while time-frequency analyses were conducted to evaluate memory-related activity, neural synchronization, and cross-frequency phase-amplitude coupling. TMAS significantly improved cognitive and working memory deficits in AD rats, enhancing long-term memory performance. Additionally, the abnormal energy levels observed in the θ and γ rhythm power spectra of the CA3 region were markedly restored, suggesting the recovery of normal neural function. This improvement was accompanied by a partial resurgence of neural activity, indicating enhanced inter-neuronal communication. Furthermore, the previously damaged coupling between the θ-fast γ and θ-slow γ rhythms was successfully improved, resulting in a notable enhancement of synchronized activity. Conclusions: These findings suggest that TMAS effectively alleviates cognitive and working memory impairments in AD rats and may provide experimental support for developing new treatments for AD. Full article

Fear is a critical welfare concern in laying hens. Fearful behaviors in domestic chickens are influenced by both genetic and environmental factors, contributing to individual differences in stress responses. Tonic immobility (TI) duration is widely recognized as a reliable indicator of fear levels. The hippocampus, a critical brain region for emotional states, plays a pivotal role in associating fearful experiences with specific stimuli, enabling adaptive behavioral responses. This study investigated hippocampal histological characteristics and transcriptomic profiles in laying hens with different fear responses categorized based on TI duration. A total of 80 native Lindian hens (75 weeks old) were individually housed in modified conventional cages. At 76 weeks of age, hens exhibiting the longest and shortest TI durations were classified into the high-fear (TH) and low-fear (TL) groups, respectively. Whole hemibrains were collected for histological and immunohistochemical analyses, while hippocampal tissues underwent transcriptome sequencing. The results showed a significant reduction in Nissl body counts in hippocampal neurons of high-fear hens (p < 0.05), suggesting potential neuronal damage or functional impairment. Transcriptomic analysis revealed 365 differentially expressed genes (DEGs) between two groups, with 277 upregulated and 88 downregulated genes in TH chickens. KEGG pathway enrichment analysis identified seven significantly associated pathways (p < 0.01), including retinol metabolism, vitamin B6 metabolism, and nicotinate and nicotinamide metabolism, all of which are crucial for neuronal function and immune regulation. In addition, a significant increase in DCX protein expression (p < 0.05) and a decrease in c-Fos protein expression (p < 0.05) was noted in in high-fear hens, whereas PCNA levels remained unchanged (p > 0.05) under immunohistochemical validation. The neuronal alterations observed in high fear individuals suggest neural damage, while transcriptomic variations point to potential disruptions in neurogenesis, synaptic signaling, and stress-related pathways. Collectively, these results provide novel insights into the neurobiological basis of fear regulation in laying hens and may have implications for poultry welfare and management strategies. Full article

Cognitive impairment in subjects with Alzheimer’s disease correlates well with the loss of synaptic plasticity. This results from mitochondrial dysfunction and production of reactive oxygen species, which damage nerve terminals causing them to release ATP and adenosine. These purines activate receptors on microglia resulting in a change in morphology and release proinflammatory cytokines that exacerbate neuronal damage. The review describes retrospective studies with naturally occurring antioxidants, vitamin E, resveratrol, Ginkgo biloba and others that suggested they reduce the incidence of Alzheimer’s disease. They have antioxidant activity in cellular systems and rodent models, but most of them failed in clinical trials, probably because they were not absorbed after oral administration or, like anti-inflammatory drugs, were not given at the right time or for long enough to detect an effect on disease progression. Ladostigil is an aminoindan derivative that is well absorbed after oral administration. It has antioxidant effects in cells and prevents cytokine release from activated microglia. In a phase 2 trial in subjects with mild cognitive impairment, ladostigil significantly reduced number of converters to Alzheimer’s disease in ApoE4-ve subjects and delayed the decline in whole brain and hippocampal volumes without causing adverse effects related to drug intake. Full article

Anxiety disorders, as common neurological diseases in clinical practice, often coexist with depression. Epidemiological surveys indicate that approximately 85% of patients with depression exhibit significant anxiety symptoms. This comorbid state not only exacerbates clinical symptoms but also leads to treatment resistance and prolonged disease duration. This study innovatively developed a compound aromatic plant essential oil (EO) formulation with remarkable anxiolytic and antidepressant effects and systematically elucidated its mechanism of action. The study found that the essential oil formulation, administered via inhalation, could significantly improve behavioral abnormalities in animals subjected to the chronic unpredictable mild stress (CUMS) model, specifically manifesting as (1) the reversal of stress-induced weight gain retardation; (2) a significant increase in sucrose preference; (3) an increase in the total distance of spontaneous activity; and (4) the prolongation of exploration time in the open arms of the elevated plus maze. Neuropathological examinations confirmed that the formulation could effectively protect the structural integrity of hippocampal neurons and alleviate CUMS-induced neural damage. In terms of mechanism of action, the study revealed that the formulation regulates the neurotransmitter system through multiple targets: (1) the upregulation of serotonin (5-HT) and γ-aminobutyric acid (GABA) levels; (2) the downregulation of glutamate (GLU) concentration; and (3) key targets identified via network pharmacological analysis, such as ESR1, STAT3, and PPARG. These findings provide molecular-level evidence for understanding the neuromodulatory effects of aromatic essential oils. Pharmaceutical formulation studies showed that the oil-in-water (O/W) type compound essential oil microemulsion, prepared using microemulsification technology, has a uniform particle size and excellent stability, maintaining stable physicochemical properties at room temperature for an extended period, thus laying a foundation for its clinical application. This study not only validates the practical value of traditional medicine but also provides new ideas for the development of novel anxiolytic and antidepressant drugs, achieving an organic integration of traditional experience and modern technology. Full article

The hippocampus is one of the brain’s most vulnerable structures to hypoxia, playing a crucial role in memory and spatial navigation. This sensitivity makes it a key region for understanding the effects of hypoxia on brain connectivity. This review examines the effects of both acute and chronic hypoxia on resting-state networks (RSNs) that contribute to hippocampal functional connectivity (FC). Hypoxia, characterized by a reduced oxygen supply to the brain, can result from environmental factors (such as high-altitude exposure) or hypoxia-induced pathological conditions (including obstructive sleep apnea and hypoxic–ischemic encephalopathy). The hippocampus’s susceptibility to hypoxic damage significantly impairs brain connectivity. This review examines through rs-fMRI studies how hypoxia alters hippocampal FC, focusing on its effects on RSNs involved in hippocampal functions, and compares acute and chronic hypoxic states. We seek to determine whether distinct or shared patterns of FC changes exist between acute and chronic hypoxia, and how hypoxia indirectly changes hippocampal FC, given the challenges of studying it in isolation. By addressing these questions, this review aims to deepen our understanding of hypoxia-induced changes in hippocampal FC and provide insights into potential therapeutic strategies to mitigate its effects on cognitive functions. Full article