Morris water maze: procedures for assessing spatial and related forms of learning and memory

Alterations of synaptic plasticity and brain oscillation are associated with autophagy induced synaptic pruning during adolescence

Adolescent brain development is characterized by significant anatomical and physiological alterations, but little is known whether and how these alterations impact the neural network. Here we investigated the development of functional networks by measuring synaptic plasticity and neural synchrony of local filed potentials (LFPs), and further explored the underlying mechanisms. LFPs in the hippocampus were recorded in young (21 ~ 25 days), adolescent (1.5 months) and adult (3 months) rats. Long term potentiation (LTP) and neural synchrony were analyzed. The results showed that the LTP was the lowest in adolescent rats. During development, the theta coupling strength was increased progressively but there was no significant change of gamma coupling between young rats and adolescent rats. The density of dendrite spines was decreased progressively during development. The lowest levels of NR2A, NR2B and PSD95 were detected in adolescent rats. Importantly, it was found that the expression levels of autophagy markers were the highest during adolescent compared to that in other developmental stages. Moreover, there were more co-localization of autophagosome and PSD95 in adolescent rats. It suggests that autophagy is possibly involved in synaptic elimination during adolescence, and further impacts synaptic plasticity and neural synchrony.

Mitochondrial protective properties exerted by JM-20 in a dementia model induced by intracerebroventricular administration of streptozotocin in mice

BACKGROUND

Mitochondrial dysfunction and brain insulin resistance have been related to Alzheimer's disease (AD) development. Streptozotocin (STZ) is commonly employed to disrupt glucose and insulin metabolism, even causing cognitive impairment in animal models. We aimed at studying the protective effect of JM-20 on STZ-induced memory impairment and brain mitochondrial dysfunction.

METHODS

Male C57Bl6 mice received 3 mg/kg STZ intracerebroventricularly and JM-20 (0.25 mg/kg or 4 mg/kg) was administered daily by gastric gavage. Episodic memory was evaluated through Y-maze, novel object recognition, and Morris water maze. Endogenous antioxidant systems (catalase and superoxide dismutase activities), total sulfhydryl groups, malondialdehyde levels were also studied and acetylcholinesterase (AChE) activity were assessed in the prefrontal cortex (PC) and hippocampus (HO).

RESULTS

demonstrated that STZ injection impaired recognition and spatial learning and memory and oxygen flow in all mitochondrial respiration states. Additionally, STZ increased AChE, superoxide dismutase, and catalase activity in the PC but not in HO tissue. A neuroprotective effect of JM-20 on STZ-induced memory decline, and mitochondrial dysfunction was observed, suggesting an important causal interaction. In addition, JM-20 was able to decreased AChE enzyme hyperactivity, rescued endogenous antioxidant systems, and prevented histologically observed neuronal damage CONCLUSION: Our results indicate that JM-20 protects against STZ-induced impairment in brain bioenergetic metabolism and memory, confirming its potential as a candidate for treating neurodegenerative disorders associated with mitochondrial dysfunction like AD.

Short chain fatty acids mediates complement C1q pathway alleviation of perioperative neurocognitive disorders

Perioperative neurocognitive disorders (PND) is one of the most common postoperative complications, which can lead to a harmful impact on self-dependence, longer hospital stays, increased medical costs, morbidity, and mortality amongst older adults. Microglia can modulate synapse elimination involved in the complement component protein 1q (C1q) pathway to induce cognitive dysfunction, which is significantly improved by short chain fatty acids (SCFAs) treatment. Here we investigate the effects of SCFAs treatment on PND via mediating C1q complement pathway. High-throughput sequencing of 16S rDNA from fecal samples of male SD rats was applied to assess the changes in gut microbiota. Fecal microbiota transplantation (FMT) was performed to investigate whether gut microbiota from PND rats could alter cognitive impairment. The blood from the rat tail vein was collected to measure the SCFAs concentrations. Hippocampal and brain tissue samples were obtained to perform Western blots, Golgi and immunofluorescence staining. Primary microglia treated with SCFAs or Histone deacetylase inhibitor were cultured to measure microglial activation states and the expression of acetylated histone. The 16S rDNA sequencing results showed that PND rats had the significant changes in the species diversity of the gut microbiota and the metabolite of specifc species. Gut microbiota from PND rats could alter spatial learning and memory, and meanwhile, the changed SCFAs concentrations in plasma were involved. The synapse elimination in PND rats was strikingly reversed by SCFAs treatment involved in modulation complement C1q via suppressing neuroinflammation. This suggests that a link between gut microbiota dysbiosis and cognitive function impairment is involved in synapse elimination via mediating complement C1q pathway. SCFAs treatment can alleviate PND, the mechanisms of which may be associated with regulating complement C1q pathway.

Modulation of tyrosine receptor imposed by estrogen in memory and cognition in female rats

The present study aimed to investigate the potential role of estrogen in modulating the pathogenesis of dementia-type-AD phenotype, possibly by tyrosine kinase. Female Wistar rats were ovariectomized (OVX) and were treated with Diethylstilbesterol (DES), an estrogen analogue (20 μg/kg/day, i.m.), and Imatinib, a tyrosine kinase inhibitor (30 mg/kg/day, orally), for two months. Animals underwent surgical ovariectomy exhibited significant memory deficits in spatial memory assessment as mean dwell time, short-term memory as spontaneous alteration, and novel object recognition after a chronic period of 4 weeks. OVX animals administered with DES produced significant restoration of memory dysfunction in comparison to OVX, as exhibited by Morris water maze (p=0.0003), Y maze (p<0.0001), and NORT. Imatinib prior to DES treatment in OVX animals showed significant decline in memory functions, which confirms the potential involvement of tyrosine receptor kinase activity in improved memory functions offered by estrogen. Levels of estradiol were significantly (p<0.0001) lower in the OVX group compared to normal which was significantly (p<0.0001) restored in the OVX+E group. Biochemical estimations of TBARS, glutathione, and acetylcholinesterase levels in the brain showed a significant increase in oxidative stress among the OVX group. However, a significant restoration of oxidative changes with TBARS (p=0.0496), glutathione (p<0.0001), and acetylcholinesterase activity (p=0.0201) of OVX animals receiving DES was observed in comparison to animals receiving imatinib followed by DES. These implications in the brain signify that estrogen and tyrosine kinase play an important role in the pathogenesis of dementia. In conclusion, estrogen offers neurochemical mediation for cognition and memory possibly via modulation of tyrosine kinase signaling in female subjects.

Neuroprotective effects of traditional Chinese medicine Naofucong on diabetic cognitive impairment: Mechanisms involving insulin-degrading enzyme-mediated degradation of Amyloid-β and inhibition of ERK/JNK/p38 MAPK signaling pathway

The increasing prevalence of diabetes and its related cognitive impairments is a significant public health concern. With limited clinical treatment options and an incomplete understanding of the underlying mechanisms, traditional Chinese medicine (TCM) Naofucong is proposed as a potential neuroprotective agent against diabetic cognitive impairment (DCI). This study aims to investigate the therapeutic mechanisms of Naofucong in DCI. We hypothesize that Naofucong may improve cognitive function in diabetic rats by modulating the extracellular regulated protein kinases (ERK)/c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinases (MAPK) signaling pathway, enhancing insulin-degrading enzyme (IDE) expression, reducing amyloid-beta (Aβ) deposition, decreasing phosphorylated Tau (p-Tau) levels, and alleviating oxidative stress. Diabetes was induced in specific-pathogen-free male Sprague-Dawley rats using streptozotocin, and the rats were treated with oral Naofucong for 12 weeks. We assessed cognitive function and measured neuronal damage, oxidative stress injury, and the expression levels of IDE, Aβ, amyloid precursor protein (APP), p-Tau, and components of the ERK/JNK/p38 MAPK pathway. Diabetic rats showed significant declines in cognitive function, neuronal damage, oxidative stress, low IDE expression, Aβ accumulation, high APP expression, abnormal Tau phosphorylation, and overactivation of the ERK/JNK/p38 MAPK pathway. Naofucong treatment significantly reversed these symptoms. Our findings suggest that Naofucong improves cognitive impairment in diabetic rats by inhibiting the ERK/JNK/p38 MAPK pathway, upregulating IDE, reducing Aβ deposition, suppressing APP and p-Tau expression, and alleviating neuronal damage and oxidative stress. This research provides a reference for the clinical prevention and treatment of DCI using TCM Naofucong.

A Scoping Review of the Mechanisms Underlying Developmental Anesthetic Neurotoxicity

Although anesthesia makes painful or uncomfortable diagnostic and interventional health care procedures tolerable, it may also disrupt key cellular processes in neurons and glia, harm the developing brain, and thereby impair cognition and behavior in children. Many years of studies using in vitro, animal behavioral, retrospective database studies in humans, and several prospective clinical trials in humans have been invaluable in discerning the potential toxicity of anesthetics. The objective of this scoping review was to synthetize the evidence from preclinical studies for various mechanisms of toxicity across diverse experimental designs and relate their findings to those of recent clinical trials in real-world settings.

Vitamin D can mitigate sepsis-associated neurodegeneration by inhibiting exogenous histone-induced pyroptosis and ferroptosis: Implications for brain protection and cognitive preservation

BACKGROUND

Sepsis-induced neurodegeneration and cognitive dysfunction remain critical challenges worldwide. Vitamin D was reported to reduce neuronal injury and neurotoxicity and its deficiency was associated with neurocognitive disorders. This study investigates the mechanisms by which vitamin D exerts neuroprotective potential against damage-associated molecular patterns (DAMPs), specifically extracellular histones, in sepsis-related brain dysfunction.

METHODS

The cultured mouse hippocampal neuronal HT22 cells were exposed to 20 µg/ml exogenous histone for 24 h to induce pyroptosis and ferroptosis in the presence or absence of the active form of vitamin D, calcitriol (1 nM). A cecal ligation and puncture mouse sepsis model was used to evaluate histone release and pyroptosis/ferroptosis biomarkers in the brain together with neurobehavioral performance with or without calcitriol treatment (1 µg/kg, i.p. injection) at 24 h or 1 week after sepsis onset.

RESULTS

In vitro, histone exposure triggered both pyroptosis and ferroptosis in neuronal cells, which was significantly suppressed by calcitriol treatment with the reduced expression of caspase-1 by 38 %, GSDMD by 30 %, ACSL4 by 33 %, and the increased expression of GPX4 by 35 % (n = 6, P < 0.05). Similarly, in vivo, calcitriol treatment inhibited both neuronal pyroptosis and ferroptosis by reducing expression of pyroptosis marker, GSDMD/NeuN (11.6 ± 1.2 % vs. 19.4 ± 1.1 %) and increasing expression of ferroptosis marker, GPX4/NeuN (21.4 ± 1.7 % vs. 13.5 ± 1.1 %), in the brain of septic mice (n = 6, P < 0.01). In addition, calcitriol increased survival rate (72 % vs. 41 %) and ameliorated cognitive dysfunction of septic mice (n = 8-13, P < 0.05).

CONCLUSIONS

This study demonstrates that vitamin D exerts a neuroprotective effect against sepsis by attenuating histone-induced pyroptosis and ferroptosis. These findings highlight the potential therapeutic role of vitamin D supplementation in mitigating brain dysfunction associated with sepsis which needs for further investigation.

Mechanism of Panax notoginseng saponins in improving cognitive impairment induced by chronic sleep deprivation based on the integrative analysis of serum metabolomics and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng saponin (PNS) has a variety of biological activities, such as improvement of myocardial ischemia, improvement of learning and memory, hypolipidemia, and immunomodulation. However, its protective mechanism on the central nervous system (CNS) is not clear.

AIM OF THE STUDY

The present study initially evaluated the possible mechanism of PNS to improve cognitive dysfunction due to chronic sleep deprivation (CSD).

MATERIALS AND METHODS

In the present study, we used a modified multi-platform aquatic environment sleep deprivation method to induce a cognitively impaired rat model, and explored the mechanism of action of PNS by integrating serum metabolomics and network pharmacology, which was further verified by molecular docking and experiments.

RESULTS

The results showed that PNS significantly shortened the escape latency, increased the target quadrant time and the number of traversing platforms, and attenuated the inflammatory damage in the hippocampal Cornu Ammonis 1 (CA1) region in CSD rats. The non-targeted metabolomics results indicated that 35 biomarkers significantly altered following PNS therapy intervention, with metabolic pathways enriched for the effects of One carbon pool by folate, Riboflavin metabolism, Glycerophospholipid metabolism, Sphingolipid metabolism, Glycerolipid metabolism, Arachidonic acid metabolism, and Tryptophan metabolism. In addition, network pharmacology identified 234 potential targets for PNS intervention in CSD with cognitive impairment. Metabolite-response-enzyme-gene network was constructed by MetaScape and matched with the network pharmacology results to identify a total of five shared targets (LPL, GPAM, HSD11B1, HSD11B2, and SULT2A1) and two metabolic pathways (Sphingolipid metabolism and Steroid hormone biosynthesis). The results of molecular docking revealed that the five active ingredients had good binding ability with the five core targets. qPCR analysis confirmed the ability of PNS to modulate the above five targets.

CONCLUSIONS

The combination of metabolomics and network analysis provides a scientific basis for promoting the clinical application of PNS in cognitive impairment.

Therapeutic potential of chrysin in regulation of interleukin-17 signaling in a repeated intranasal amyloid-beta-induced Alzheimer's disease model

Objective: The aim of the current study was to study the therapeutic potential of chrysin against repeated intranasal amyloid-beta (Aβ)-induced interleukin-17 (IL-17) signaling in a mouse model of AD. Methods: Male BALB/c mice were daily exposed to intranasal Aβ1-42 (10 μg/10 μL) for seven consecutive days. Chrysin was orally administered at doses of 25, 50 and 100 mg kg-1 in 0.5% sodium carboxy methyl cellulose suspension from day 5 of Aβ1-42 administration for seven days. Following the treatment, the memory of the animals was appraised using Morris water maze, novel object recognition and passive avoidance tests. Further, the effects of chrysin on Aβ1-42-induced IL-17 signaling and redox levels were evaluated in the cortex and hippocampus regions of the mouse brain through western blot and immunohistochemistry. Results: The exposure to Aβ1-42 through the intranasal route induced a significant decline in the spatial, learning and cognitive memory of the animals, and most interestingly, exposure to Aβ1-42 triggered IL-17-mediated signaling, which resulted in a significant increase in the expression of IL-17RA, Act1 and TRAF6. Furthermore, Aβ1-42 impaired the tissue redox level and inflammatory cytokines in the mouse brain. Alternatively, treatment with chrysin at 25, 50 and 100 mg kg-1 oral doses alleviated Aβ1-42-mediated memory decline, impaired redox levels and inflammation. Specifically, chrysin downregulated the expression of IL-17 and mediated signaling in the brain regions of the mice. Conclusion: Chrysin was evidenced to be a potent antioxidant and anti-inflammatory agent, clearly showing a protective role against Aβ1-42-induced IL-17-mediated inflammation in the brain of the mice.

Sex differences in cognition, anxiety-phenotype and therapeutic effect of metformin in the aged apoE-TR mice

BACKGROUND

Apolipoprotein E4 (ApoE4) is associated with an increased risk of Alzheimer's disease (AD), depression, and anxiety, which were reported to improve after the administration of metformin. However, sex influence on the effect of ApoE4 and metformin on cognition and mental health is poorly understood.

METHODS

ApoE3-TR and apoE4-TR mice of both sexes were randomly assigned to the normal saline and metformin groups from 13 months to 18 months of age. Behavior tests (MWM, EPM, OFT, TST, FST) were conducted to assess cognition, anxiety, and depression-like behaviors. The mice's blood glucose was also recorded.

RESULTS

Male aged apoE4-TR mice are more vulnerable to cognitive decline than females. Metformin improves the spatial memory of female, but not male apoE3-TR mice and female apoE4-TR mice while aggravating the cognitive impairment of male apoE4-TR mice. The anxiety-like phenotypes in male apoE4-TR mice are more severe than in male apoE3-TR mice, while metformin ameliorates the anxiety-like behaviors in the male apoE4-TR mice but not in male apoE3-TR mice. In addition, metformin alleviates depression-like behaviors in male and female apoE4-TR mice. The hypoglycemic effect of metformin is insignificant in both male and female apoE4-TR mice.

CONCLUSIONS

Male sex exacerbates APOE4-related cognitive impairment and anxiety in aged mice and is insensitive to the cognition improvement effect of metformin in the aged apoE3 mice. Male sex with APOE4 may experience more severe cognitive impairment after treatment with metformin while sensitive to the anti-anxiety effects of metformin. These findings identify sex-specific effects on ApoE4-based dementia, anxiety prevention, and therapy, emphasizing the importance of further sex dimension analyses in vivo and clinical studies.

Oral administration of crocin reverses memory loss induced by ethanol and nicotine abstinence in adolescent male rats

PURPOSE

Regarding a wide variety of researches conducted with various therapeutic effect of crocin, the main constituent of saffron, the current study aims to assess the efficacy of crocin to improve learning and memory impairment caused by withdrawal following concurrent usage of ethanol (Eth) and nicotine (Nic) in adolescent male rats.

METHODS

In order to test memory fucntion, Morris water maze and passive avoidance methods were applied in male Wistar rats undergone adolescent Nic-Eth withdrawal and the effect of crocin treatment was assessed at both behavioral and biochemical levels. The biochemical parameters included the inflammatory cytokines, indicators of oxidative stress and cholinergic metabolism within the hippocampla tissues. Animals were divided into 7 experimental groups as follows: 1) control (saline + saline), 2) nicotine + ethanol, 3-5) nicotine + ethanol + crocin (three doses), 6) nicotine + ethanol + bupropion + naloxone and 7) saline + crocin.

RESULTS

Results indicated that crocin treatment effectively prevented the Nic-Eth withdrawal induced behavioral manifestations of memory impairment when assessed by Morris water maze and passive avoidance tests. In addition, the biochemical alterations (in inflammatory, oxidative and cholinergic parameters) induced by Nic-Eth withdrawal were also ameliorated in rats treated by crocin. Interestingly, the mentioned ameliorative effect of crocin was found to be dose-dependent in most experiments and almost equipotential to that of bupropion and naloxone co-administration, when administered at high doses.

CONCLUSION

We would like to suggest the crocin treatment as an alternative medication for the management of Nic - Eth withdrawal, however, further studies are required to assess the unknown side effects and high dose tolerability of the drug in human subjects.

Sleep fragmentation impairs cognitive function and exacerbates Alzheimer's disease-related pathology in a mouse model by disrupting mitochondrial biogenesis

A large proportion of Alzheimer's disease (AD) patients suffer from various types of chronic sleep disturbances, including sleep fragmentation (SF). In addition, impaired mitochondrial biogenesis is an important feature of AD, but whether it is altered in sleep disorders has not been fully elucidated. Hence, we aimed to investigate the relationship between SF and mitochondrial biogenesis and the possible impact of SF on AD-related pathology. In this study, thirty-six 9-month-old 3xTgAD model mice and thirty-six 9-month-old wild-type (WT) C57BL/6 J mice were divided into a control group (6 weeks of normal sleep), a SF group (6 weeks of SF) and a SF + recovery sleep group (6 weeks of SF followed by 2 weeks of recovery sleep). Cognitive functions were assessed by behavioural experiments. Mitochondrial structure and function and the activity of a classic mitochondrial biogenesis signalling pathway were investigated using transmission electron microscopy (TEM), reverse transcription quantitative polymerase chain reaction (RT-qPCR), immunofluorescence and Western blotting. Markers of AD-related pathology, including the levels of amyloid β (Aβ) and tau proteins, were assessed by immunofluorescence and Western blotting. The expression of insulin-degrading enzyme (IDE) was assessed by Western blotting. We found that long-term SF impaired the cognitive functions of the mice. In addition, chronic SF reduced the expression of mitochondrial respiratory chain components, the number of mitochondria, the fluorescence intensity of COX-IV, the level of mitochondrial DNA (mtDNA) and the expression of crucial regulators of the AMPK/SIRT-1/PGC-1α signalling pathway in the mouse prefrontal cortex and hippocampus, while recovery sleep could partly abrogate these effects. Moreover, SF reduced the protein level of IDE and increased the Aβ burden and tau hyperphosphorylation. This study demonstrates that chronic SF can negatively regulate the AMPK/SIRT-1/PGC-1α signalling pathway to disrupt mitochondrial biogenesis in the brains of mice, which may subsequently exacerbate AD-related pathology by decreasing the expression of IDE.

Co-delivery of curcumin-resveratrol-carnosic acid complex promotes neurogenesis and cognitive recovery in a rodent model of repeated mild traumatic brain injury

Repeated traumatic brain injury has grown in importance as sports-related injuries have increased. Repetitive mild TBI (rmTBI) increases the risk of developing neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, as well as chronic comorbidities like PTSD, depression, substance abuse and neuroendocrine functions. However, no effective therapeutic strategies have been reported for the effective management of TBI. Herein, we examined the effectiveness of co-delivery of the phytonutrients curcumin, trans-resveratrol, and carnosic acid as a bioavailable complex (CGM+) in managing rmTBI in the rodent model. The rats were randomly assigned to sham, rmTBI, and CGM+ (300 mg/kg b.wt.) groups for a total of 21 days. On Days 6 and 7, all animals, except those in the sham group, were subjected to repeated mild traumatic brain injury (rmTBI). The CGM+ group received supplementation throughout the 21 days, while the other groups received a vehicle. Neurological severity score (NSS) was assessed 24 h after the last injury, and behavioral tests were completed within 14 days post-injury. Samples for the biochemical analysis were collected after euthanasia. CGM+ supplementation significantly decreased the sensory-motor deficits associated with rmTBI. Following TBI, the CGM+ group demonstrated enhanced memory and low-stress levels. Furthermore, CGM+ has been shown to modulate neurotransmitter levels and promote neurogenesis. The biochemical and molecular analysis revealed that CGM+ promotes recovery following rmTBI by modulating mitochondrial bioenergetics and BDNF pathways. The findings indicate that CGM+ can be used to manage cognitive and sensory-motor defects caused by rmTBI, such as in the case of sports injuries.

Inhibition of platelet activation alleviates diabetes-associated cognitive dysfunction via attenuating blood-brain barrier injury

Cognitive dysfunction has become the second leading cause of death among the diabetic patients. In pre-diabetic stage, blood-brain barrier (BBB) injury occurs and induced the microvascular complications of diabetes, especially, diabetes-associated cognitive dysfunction (DACD). Endothelial cells are the major component of BBB, on which the increased expression of CD40 could mediate BBB dysfunction in diabetics. Since platelets play an important role in regulating endothelial cell barrier function and over 95 % of the circulating soluble CD40 ligand (sCD40L) is derived from activated platelets, we speculated that the release of CD40L from activated platelets induced by diabetes was the key mechanism that aggravated BBB injury and leaded to DACD. We performed inhibition of platelet activation on diabetic and non-diabetic mice, with or without cilostazol treatment, and then compared cognitive function, platelet activation, BBB structure and permeability. In vitro, mouse brain microvascular endothelial cell line (b.End3) were exposed to CD40L for 24 h at 5.5 mM or 30 mM glucose media after silencing CD40 and HIF1α or not to investigate the effects of CD40 on BBB disruption and the underlying molecular pathways. Inhibition of platelet activation improved cognitive behaviors in diabetic mice, accompanied with reduced BBB permeability, increased tight junction proteins, balanced Aβ transporters, as well as attenuated Aβ deposition and hippocampal neurons damage. In vitro, CD40L increased HIF1α, diminished tight junction proteins and dysregulated Aβ transporters in b.End3 cells, which could be restored by CD40 siRNA and HIF1α siRNA. Hence, inhibition of platelet activation ameliorates DACD via alleviating BBB injury, which involving the regulation of CD40L-CD40-HIF1α signaling pathway. Our study may demonstrate a potential therapeutic target for the treatment of DACD.

TESC overexpression mitigates amyloid-β-induced hippocampal atrophy and memory decline

BACKGROUND AND OBJECTIVES

Genome-wide association studies (GWASs) have identified numerous candidate genes for human brain-imaging phenotypes; however, the biological relevance of many of these genes remains unconfirmed. This study aimed to investigate the causal relationships among tescalcin (TESC) (a GWAS-indicated gene), hippocampal volume, Alzheimer's disease (AD), and the underlying biological mechanisms.

METHODS

Human transcriptional data were analyzed to confirm relative TESC expression in the hippocampus. In cell experiments, RNA-seq analysis was used to identify the potential biological pathways for TESC overexpression, and immunofluorescence imaging and cell viability assays were used to evaluate the effect of TESC overexpression on neuronal structure and survival. In animal experiments, the effects of TESC overexpression on hippocampal volume and cognitive function in normal mice and amyloid-β (Aβ)-induced AD mice were investigated by 9.4 T magnetic resonance imaging and behavioral tests. Underlying mechanisms were further assessed via western blotting and electrophysiological recordings.

RESULTS

Human transcriptional data demonstrated that TESC is primarily expressed in the hippocampus and neurons. TESC overexpression enhanced the viability of HT22 cells and reduced Aβ-induced cell death. In mouse models, Tesc-overexpressing mice revealed increased hippocampal volume, likely owing to enhanced cell viability and long-term potentiation (LTP), and reducing apoptotic- and oxidation-induced hippocampal damage. TESC overexpression could significantly mitigate Aβ-induced hippocampal atrophy and memory impairment, potentially by reducing Aβ-induced neuronal apoptosis and LTP weakening.

CONCLUSION

This study exemplifies the translation of GWAS findings into actionable biological knowledge and suggests that upregulation of TESC may offer a promising therapeutic strategy for AD.

Intermittent hypoxia-hyperoxia training ameliorates cognitive impairment and neuroinflammation in a rat model of Alzheimer's disease

Alzheimer's disease (AD), characterized by severe and progressive cognitive decline, stands as one of the most prevalent and devastating forms of dementia. Based on our recent findings showing intermittent hypoxic conditioning improved neuronal function in patients with mild cognitive impairment, the present study aimed at investigating whether the neuroprotective effects of intermittent hypoxia can be replicated in a rat model of AD, which allows us to explore the underlying cellular mechanisms involving neuroinflammation, hypoxia inducible factor 1α (HIF1α), and cytochrome P450 family 2 subfamily E member 1 (CYP2E1). Forty-one adult male Wistar rats were randomly assigned to three groups: 1) Control group: received intracerebroventricular (ICV) injection of saline; 2) STZ group: received ICV injection of streptozotocin (STZ) to induce AD-like pathology; and 3) STZ + IHHT group received ICV injection of STZ as well as 15 daily sessions of intermittent hypoxia-hyperoxia training (IHHT). We observed that ICV injection of STZ inhibited spatial learning and memory in the rats assessed with Morris Water Maze test. The cognitive function declines were accompanied by increased expression of amyloid β peptide (Aβ), HIF1α, CYP2E1, and TNFα in hippocampus. Interestingly, IHHT significantly restored the STZ-induced cognitive dysfunction, while reduced expression of Aβ, CYP2E1, HIF1α and TNFα. We conclude that IHHT with mild hypoxia-hyperoxia can enhance spatial learning and memory and reduce the AD-like pathologic changes in rats. The neuroprotective outcome of IHHT may be related to anti-inflammatory effects in hippocampus.

Exosomal miR-302b rejuvenates aging mice by reversing the proliferative arrest of senescent cells

Cellular senescence, a hallmark of aging, involves a stable exit from the cell cycle. Senescent cells (SnCs) are closely associated with aging and aging-related disorders, making them potential targets for anti-aging interventions. In this study, we demonstrated that human embryonic stem cell-derived exosomes (hESC-Exos) reversed senescence by restoring the proliferative capacity of SnCs in vitro. In aging mice, hESC-Exos treatment remodeled the proliferative landscape of SnCs, leading to rejuvenation, as evidenced by extended lifespan, improved physical performance, and reduced aging markers. Ago2 Clip-seq analysis identified miR-302b enriched in hESC-Exos that specifically targeted the cell cycle inhibitors Cdkn1a and Ccng2. Furthermore, miR-302b treatment reversed the proliferative arrest of SnCs in vivo, resulting in rejuvenation without safety concerns over a 24-month observation period. These findings demonstrate that exosomal miR-302b has the potential to reverse cellular senescence, offering a promising approach to mitigate senescence-related pathologies and aging.

Cognitive impairment and hippocampal degeneration in aged rat models of type 2 diabetes with induced glycemic fluctuation: A pilot study

OBJECTIVE

Effective methods for establishing an aged animal model of diabetes and glycemic fluctuation have rarely been investigated. The aim of the study was to explore the feasibility of inducing glycemic fluctuation in aged Sprague-Dawley rats and to evaluate the corresponding changes in cognitive function.

METHODS

Male rats aged 48 weeks were fed a high-fat and high-glucose diet and given streptozotocin intraperitoneally to establish a rat model of type 2 diabetes mellitus (T2DM). Then, glycemic fluctuation was induced via three different protocols: (1) intraperitoneal injection of glucose; (2) sequential fasting, insulin injection, and normal diet; and (3) intermittent intraperitoneal injections of glucose and insulin.

RESULTS

All three protocols were effective at inducing glycemic fluctuation in aged rats with T2DM, with successful modeling rates of 60 %, 90 %, and 70 %, respectively. Aged T2DM rats with glycemic fluctuation showed significant increases in glycemic variability compared with controls, including in the mean blood glucose, postprandial glycemic excursion, largest amplitude of glycemic excursion, and standard deviation of blood glucose values (all P < 0.05). Additionally, rats with glycemic fluctuation had more severe insulin resistance and dyslipidemia (P < 0.05). Morris water maze testing showed a trend of longer escape latency in the navigation test for rats in the glycemic fluctuation groups, suggesting impaired cognitive function. Pathological analysis showed degenerative changes in the CA1 hippocampal region of rats in the glycemic fluctuation groups. Finally, differential gene expression analysis revealed 1323 significantly altered genes in the GV group, with 691 upregulated and 632 downregulated. The dysregulated genes were predominantly associated with the axon guidance pathway and potassium channel regulation.

CONCLUSIONS

The proposed protocols were effective at establishing an aged T2DM rat model with glycemic fluctuation, and rats with glycemic fluctuation exhibited diminished cognitive function.

Oral Supplements of Combined Lactobacillus plantarum and Asparagus officinalis Modulate Gut Microbiota and Alleviate High-Fat Diet-Induced Cognitive Deficits and Neurodegeneration in Rats

High-fat diet (HFD) consumption disrupts the gut microbiome, instigating metabolic disturbance, brain pathology, and cognitive decline via the gut-brain axis. Probiotic and prebiotic supplementation have been found to improve gut microbiome health, suggesting they could be effective in managing neurodegenerative disorders. This study explored the potential benefits of the probiotic strain Lactobacillus plantarum 20174 (L. plantarum), prebiotic Asparagus officinalis (A. officinalis) extract, or their synbiotic combination against HFD-induced cognitive dysfunction and neurodegeneration in rats. Male Sprague-Dawley rats were fed either a normal diet or an HFD for 24 weeks. Starting from week 13, rats on either diet were divided into vehicle-, prebiotic-, probiotic-, and synbiotic-treated subgroups. Rats received their assigned intervention for 12 more weeks. Prebiotic, probiotic, or synbiotic treatment reverted HFD-instigated alterations in hippocampal amyloid beta, p-tau, α-synuclein, and BDNF levels, leading to restored cognitive function. The tested therapies also improved the HFD-disrupted lipid profile. Interestingly, probiotic and synbiotic therapies attenuated oxidative stress and inflammation, reinstated neurotransmitter balance, and mitigated the energy deficit in HFD-fed rats. Furthermore, L. plantarum and Asparagus administration modulated gut microbiota composition by raising Lactobacillus species and reducing Coliform and Staphylococci bacteria as well as fungi populations. These findings suggest that the oral consumption of A. officinalis prebiotics and/or L. plantarum probiotics alleviates HFD-induced cognitive deficit and neurodegeneration through modulation of the gut-brain axis with superior restorative effects being achieved by synbiotic treatment.

Microbiota-derived lysophosphatidylcholine alleviates Alzheimer's disease pathology via suppressing ferroptosis

Alzheimer's disease (AD) is a pervasive neurodegenerative disorder, and new approaches for its prevention and therapy are critically needed. Here, we elucidate a gut-microbiome-brain axis that offers actionable perspectives for achieving this objective. Using the 5xFAD mouse model, we identify increased Clostridium abundance and decreased Bacteroides abundance as key features associated with β-amyloid (Aβ) burden. Treatment with Bacteroides ovatus, or its associated metabolite lysophosphatidylcholine (LPC), significantly reduces Aβ load and ameliorates cognitive impairment. Mechanistically, LPC acts through the orphan receptor GPR119, inhibiting ACSL4 expression, thereby suppressing ferroptosis and ameliorating AD pathologies. Analysis of fecal and serum samples from individuals with AD also reveals diminished levels of Bacteroides and LPC. This study thus identifies a B.ovatus-triggered pathway regulating AD pathologies and indicates that the use of single gut microbiota, metabolite, or small molecule compound may complement current prevention and treatment approaches for AD.

Xixin Decoction's novel mechanism for alleviating Alzheimer's disease cognitive dysfunction by modulating amyloid-β transport across the blood-brain barrier to reduce neuroinflammation

Purpose

Xixin Decoction (XXD) is a classical formula that has been used to effectively treat dementia for over 300 years. Modern clinical studies have demonstrated its significant therapeutic effects in treating Alzheimer's disease (AD) without notable adverse reactions. Nevertheless, the specific mechanisms underlying its efficacy remain to be elucidated. This investigation sought to elucidate XXD's impact on various aspects of AD pathology, including blood-brain barrier (BBB) impairment, neuroinflammatory processes, and amyloid-β (Aβ) deposition, as well as the molecular pathways involved in these effects.

Methods

In vitro experiments were conducted using hCMEC/D3 and HBVP cell coculture to establish an in vitro blood-brain barrier (BBB) model. BBB damage was induced in this model by 24-h exposure to 1 μg/mL lipopolysaccharide (LPS). After 24, 48, and 72 h of treatment with 10% XXD-medicated serum, the effects of XXD were assessed through Western blotting, RT-PCR, and immunofluorescence techniques. In vivo, SAMP8 mice were administered various doses of XXD via gavage for 8 weeks, including high-dose XXD group (H-XXD) at 5.07 g kg-1·d-1, medium-dose XXD group (M-XXD) at 2.535 g kg-1·d-1, and low-dose XXD group (L-XXD) at 1.2675 g kg-1·d-1. Cognitive function was subsequently evaluated using the Morris water maze test. BBB integrity was evaluated using Evans blue staining, and protein expression levels were analyzed via ELISA, Western blotting, and immunofluorescence.

Results

In vitro experiments revealed that XXD-containing serum, when cultured for 24, 48, and 72 h, could upregulate the expression of P-gp mRNA and protein, downregulate CB1 protein expression, and upregulate CB2 and Mfsd2a protein expression. In vivo studies demonstrated that XXD improved spatial learning and memory abilities in SAMP8 mice, reduced the amount of Evans blue extravasation in brain tissues, modulated the BBB-associated P-gp/ECS axis, RAGE/LRP1 receptor system, as well as MRP2 and Mfsd2a proteins, and decreased the accumulation of Aβ in the brains of SAMP8 mice. Additionally, XXD upregulated the expression of TREM2, downregulated IBA1, TLR1, TLR2, and CMPK2 expression, and reduced the levels of pro-inflammatory factors NLRP3, NF-κB p65, COX-2, TNF-α, and IL-1β in the hippocampal tissues.

Conclusion

XXD may exert its effects by regulating the P-gp/ECS axis, the RAGE/LRP1 receptor system, and the expression of MRP2 and Mfsd2a proteins, thereby modulating the transport function of the BBB to expedite the clearance of Aβ, reduce cerebral Aβ accumulation, and consequently inhibit the activation of microglia induced by Aβ aggregation. This process may suppress the activation of the CMPK2/NLRP3 and TLRs/NF-κB pathways, diminish the production of inflammatory cytokines and chemokines, alleviate neuroinflammation associated with microglia in the brain of AD, and ultimately improve AD pathology.

Calcium/calmodulin-dependent protein kinase II α and β differentially regulate mammalian sleep

While sleep is important, our understanding of its molecular mechanisms is limited. Over the last two decades, protein kinases including Ca2+/calmodulin-dependent protein kinase II (CaMKII) α and β have been implicated in sleep regulation. Of all the known mouse genetic mutants, the biggest changes in sleep is reported to be observed in adult mice with sgRNAs for Camk2b injected into their embryos: sleep is reduced by approximately 120 min (mins) over 24 h (hrs). We have reexamined the sleep phenotype in mice with either Camk2a or Camk2b gene knocked-out by conventional gene targetting. While the basal sleep is reduced in Camk2a knockout mice, it remains unaltered in Camk2b mutants. Knockout of either Camk2a or Camk2b reduces sleep rebound after deprivation, indicating their roles in sleep homeostasis. These results indicate the involvement of CaMKIIα in both basal sleep and sleep homeostasis while CaMKIIβ is mainly required physiologically for sleep homeostasis, serving as a stimulus for rigorous studies in the future.

Assessment of cFos labeling in the hippocampus and anterior cingulate cortex following recent and remote re-exposure to an unreinforced open field in preadolescent and postadolescent rats

Spatial tasks are often goal-directed or reward-facilitated confounding the assessment of "pure" recent and remote spatial memories. The current work re-exposed preadolescent and postadolescent male rats to a non-reinforced, free exploration task to investigate cFos patterns within the hippocampus and anterior cingulate cortex (ACC) associated with recent and remote periods. Male rats were exposed to an open field task for one, 30 min session on postnatal day (P) 20, 25, or 50 and re-exposed for 30 min at either a recent (24 hours) or remote (3 weeks) timepoint. Distance traveled in the open field was measured as well as cFos labeling. In the P20 age group, there was elevated exploration at the 24-hour and 3-week tests compared to training and compared to the other age groups. In the hippocampus CA1, cFos levels were higher after the remote test than the recent test in the P20 group but higher after the recent test than remote test in the P25 and P50 groups. cFos labeling in the ACC was higher in all remote-tested groups compared to the recent-tested groups across all ages. In the P20, the 24-hour test was associated with less CA1 activity than the other age groups supporting the hypothesis that the hippocampus is not fully developed at this time point. In the P20 group, the remote representation of this task did not seem to be complete as there continued to be CA1 activity along with ACC activity following the remote test associated with elevated exploration. These results indicate the utility of unreinforced spatial navigation tasks for exploring systems consolidation processes over the lifespan and show that a fully developed hippocampus is required for optimal systems consolidation.

Minocycline ameliorates cognitive impairment in rats with trigeminal neuralgia by regulating microglial polarization

Trigeminal neuralgia (TN)-related cognitive impairment is a common cause of decreased quality of life in patients and is closely associated with neuroinflammation. Although minocycline has demonstrated anti-inflammatory, analgesic, and neuroprotective functions, its role in treating TN-related cognitive impairment remains unreported. In this study, we used an in vivo TN model and an in vitro model of primary microglial neuroinflammation to investigate the potential effects of minocycline on cognitive function and microglial polarization in TN rats. Our results suggested that minocycline treatment attenuated cognitive deficits by alleviating hippocampal neuronal damage and enhancing synaptic plasticity in TN rats. Furthermore, both in vitro and in vivo assays demonstrated that minocycline polarized activated microglia to the M2 phenotype, leading to the reduction of pro-inflammatory factors, including tumor necrosis factor-α and interleukin-1, and an increase in the anti-inflammatory factors, such as interleukin-4 and interleukin-10, thereby attenuating neuroinflammation. Moreover, it was found that the TLR4/MyD88/NF-κB pathway was involved in the shift of microglia from a pro-inflammatory (M1) to an anti-inflammatory (M2). In summary, minocycline likely mediated the process of microglia polarization partly via the TLR4/MyD88/NF-κB pathway, promoting neuronal survival and restoring synaptic plasticity, thereby improving TN-related cognitive impairment.

Mouse Testing Methods in Psychoneuroimmunology: Measuring Behavioral Responses

The field of psychoneuroimmunology (PNI) aims to uncover the processes and consequences of nervous, immune, and endocrine system relationships. Behavior is a consequence of such interactions and manifests from a complex interweave of factors including immune-to-neural and neural-to-immune communication. Often the signaling molecules involved during a particular episode of neuroimmune activation are not known, but behavioral response provides evidence that bioactives such as neurotransmitters and cytokines are perturbed. Immunobehavioral phenotyping is a first-line approach when examining the neuroimmune system and its reaction to immune stimulation or suppression. Behavioral response is significantly more sensitive than direct measurement of a single specific bioactive and can quickly and efficiently rule in or out relevance of a particular immune challenge or therapeutic to neuroimmunity. Classically, immunobehavioral research was focused on sickness symptoms related to bacterial infection, but neuroimmune activation is now a recognized complication of diseases and disorders ranging from cancer to diabesity to Alzheimer's. Immunobehaviors include lethargy, loss of appetite, and disinterest in social activity/surrounding environment. In addition, neuroimmune activation can diminish physical activity, precipitate feelings of depression and anxiety, and impair cognitive and executive function. Provided is a detailed overview of behavioral tests frequently used to examine neuroimmune activation in mice with a special emphasis on pre-experimental conditions that can confound or prevent successful immunobehavioral experimentation.

Protein Phosphatase 2ACα Regulates ATR-Mediated Endogenous DNA Damage Response Against Microcephaly

Protein phosphatase 2A (PP2A) is an abundant heterotrimeric holoenzyme in eukaryotic cells coordinating with specific kinases to regulate spatial-temporal protein dephosphorylation in various biological processes. However, the function of PP2A in cortical neurogenesis remains largely unknown. Here, we report that neuronal-specific deletion of Pp2acα in mice displayed microcephaly, with significantly smaller brains and defective learning and memory ability. Mechanistically, neuronal Pp2acα deficiency resulted in elevated endogenous DNA damage and activation of ATR/CHK1 signaling. It was further induced by the loss of direct interaction between PP2AC and ATR as well as the function of PP2AC to dephosphorylate ATR. Importantly, ATR/CHK1 signaling dysregulation altered both the expression and activity of several critical downstream factors including P53, P21, Bcl2, and Bax, which led to decreased proliferation of cortical progenitor cells and increased apoptosis in developing cortical neurons. Taken together, our results indicate an essential function of PP2ACα in endogenous DNA damage response-mediated ATR signaling during neurogenesis, and defective PP2ACα in neurons contributes to microcephaly.

Study on the Therapeutic Effects of Bisdemethoxycurcumin on a Cerebral Amyloid Angiopathy Mouse Model Established via Chronic Treatment With Five Vascular Risk Factors

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is recognized as a major contributor to progressive cognitive decline and cerebral hemorrhages in the elderly population. Currently, there is a global shortage of safe and effective treatments for this condition. Bisdemethoxycurcumin (BDMC) has been demonstrated to exhibit pharmacological effects with anti-Aβ toxicity properties. Thus, the present study mainly focused on the potential therapeutic effects of BDMC on CAA.

METHOD

The 30 male C57BL/6 mice were subjected to chronic treatment with five vascular risk factors (lipopolysaccharide, social stress, streptozotocin, high-cholesterol diet, and copper-containing drinking water) for 35 weeks to establish a CAA mouse model. Of these, 15 CAA mice received oral administration of BDMC (50 mg/kg) for two consecutive weeks as an intervention, while the remaining 15 CAA mice received an equal volume of physiological saline by gavage. The study observed the levels of Aβ40 and proinflammatory factors in brain tissue and plasma, Aβ deposition in cerebral blood vessels, microbleeds in brain tissue, expression of proteins related to the cGAS/STING signaling pathway in brain tissue, as well as the contents of p-RIPK-1, p-RIPK-3, p-MLKL, neuronal morphology, and learning and memory abilities in mice.

RESULT

The therapeutic administration of BDMC demonstrates a pronounced efficacy in alleviating Aβ burden and cerebral microbleeding in CAA mice, concurrently enhancing learning and memory capabilities. Interestingly, BDMC may inhibits neuroinflammatory responses by reducing the expression of cGAS/STING signaling pathway proteins and suppresses necroptosis.

CONCLUSION

Our research findings demonstrate that BDMC exerts therapeutic effects in a mouse model of CAA established through chronic treatment involving five vascular risk factors.

Neurocognitive impairments in rat offspring after maternal exposure to vortioxetine: Involvement of BDNF, apoptosis and cholinergic mediated signaling pathways

Depression in pregnant women raises concerns about the safety of antidepressants use, particularly its impact on offspring's neurocognition. This study investigates the effects of maternal exposure to vortioxetine (VOX) on the neurocognitive development of rat offspring. Pregnant Wistar rats were administered clinically pertinent doses of VOX, 1 mg/kg/day or 2 mg/kg/day from gestational day 6-21. The dams delivered their offspring naturally and reared until postnatal day (PND) 70. Offspring of both sexes were assessed for postnatal growth by measuring body weight from PND 1-70 weekly and cognitive function using Morris water maze (MWM) test and passive avoidance learning test from PND 49-70. After behavioral assessments, adult rat offspring were sacrificed, and their brains were dissected out for assessment of brain morphology as well as biochemical analysis. The results demonstrated that VOX exposure potentially impaired cognitive performance, evidenced by increased latency in MWM and passive avoidance learning tests. Additionally, it led to decreased body weight, altered brain morphology, and disrupted neurobiochemical profiles. Specifically, VOX 2 mg/kg exposure significantly reduced brain-derived neurotrophic factor (BDNF) expression, increased pro-apoptotic BAX expression, decreased anti-apoptotic Bcl-2 expression, and elevated acetylcholinesterase (AChE) activity in the hippocampus. Lower dose of VOX (1 mg/kg) did not show significant adverse effects on neurocognition, suggesting a dose-dependent impact. No sex specific neurocognitive deficits were observed in current study. These findings indicate that while VOX may offer a safer profile compared to SSRIs, high doses during pregnancy can still result in neurocognitive impairments in offspring.

Voluntary running exercise promotes maturation differentiation and myelination of oligodendrocytes around Aβ plaques in the medial prefrontal cortex of APP/PS1 mice

BACKGROUND

Previous studies have reported that running exercise could improves myelinization in hippocampus. However, the effects of running exercise on the differentiation and maturation of oligodendrocytes, and myelination surrounding Aβ plaques in the medial prefrontal cortex (mPFC) of the Alzheimer's disease (AD) brain have not been reported.

METHODS

Forty 10-month-old male APP/PS1 AD mice were randomly divided into the AD group and the AD running (AD+RUN) group, while 20 age-matched wild-type littermate mice were included in the WT group. The running group received three-month voluntary running exercise in a running cage, while the AD and WT groups were untreated. After the exercise intervention, all mice were given behavioral tests. The total number of mature oligodendrocytes (CC1+) in the mPFC of mice was precisely quantified using unbiased stereology. Myelin basic protein (MBP) and Aβ plaque, as well as the fluorescence area of MBP surrounding Aβ plaques, and the density and morphology of PDGFα+ cells in the mPFC were analyzed using immunofluorescence.

RESULTS

The levels of working memory, cognitive memory, spatial learning and memory ability were decreased significantly in the AD group compared to the WT group, while these functions were significantly improved in the AD+RUN group compared to the AD group. The Aβ plaques in the mPFC were significantly reduced in the AD+RUN group compared to the AD group. The total number of CC1+ cells and the percentage of MBP fluorescence area surrounding Aβ plaques in the mPFC were significantly lower in the AD group compared to the WT group, but they were significantly higher in the AD+RUN group compared to the AD group. The density and branching complexity of PDGFα+ cells surrounding Aβ plaques in the mPFC were significantly higher in the AD group than in the WT group, while the AD+RUN group showed significantly lower density and branching complexity than the AD group. Changes in MBP expression around Aβ plaques, cell density and cell branching complexity of PDGFα+ cells around Aβ plaques were closely related to the number of Aβ plaques in mPFC, and they were also closely related to behavioral changes in mice.

CONCLUSIONS

Voluntary running exercise could reduce Aβ plaque deposition and promote the maturation and myelination capacity of oligodendrocytes surrounding Aβ plaques in the mPFC of AD mice, thereby improving the learning and memory abilities of APP/PS1 transgenic AD mice.

Therapeutic Potential of Ocimum basilicum L. Extract in Alleviating Autistic-Like Behaviors Induced by Maternal Separation Stress in Mice: Role of Neuroinflammation and Oxidative Stress

A confluence of genetic, environmental, and epigenetic factors shapes autism spectrum disorder (ASD). Early-life stressors like MS play a contributing role in this multifaceted neurodevelopmental disorder. This research was to explore the efficacy of Ocimum basilicum L. (O.B.) extract in mitigating behaviors reminiscent of autism prompted by maternal separation (MS) stress in male mice, focusing on its impact on neuroinflammation and oxidative stress. MS mice were treated with O.B. extract at varying dosages (20, 40, and 60 mg/kg) from postnatal days (PND) 51-53 to PND 58-60. Behavioral experiments, including the Morris water maze, three-chamber test, shuttle box, and resident-intruder test, were conducted post-treatment. The method of maternal separation involved separating the pups from their mothers for 3 h daily, from PND 2 to PND 14. Molecular analysis of hippocampal tissue was performed to assess gene expression of Toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). Hippocampal and serum malondialdehyde (MDA) levels and total antioxidant capacity (TAC) were measured. O.B. extract administration resulted in the amelioration of autistic-like behaviors in MS mice, as evidenced by improved spatial and passive avoidance memories and social interactions, as well as reduced aggression in behavioral tests. O.B. extract attenuated oxidative stress and neuroinflammation, as indicated by decreased MDA and increased TAC levels, as well as downregulation of TLR4, TNF-α, and IL-1β expression in the hippocampus. O.B. extract may offer a novel therapeutic avenue for ASD, potentially mediated through its anti-inflammatory and antioxidant properties.

Structural optimization of naturally derived Ar-turmerone, as novel neuroinflammation suppressors effective in an Alzheimer mouse model

Microglia-mediated neuroinflammation plays a pivotal role in neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. The modulation of chronic and sustained inflammatory processes in the brain with small molecules presents a promising therapeutic strategy for these devastating conditions. Aromatic turmerone (ar-turmerone, ART), an active constituent of turmeric essential oil derived from the edible plant Curcuma longa, has shown substantial potential in mitigating neuroinflammatory responses and associated cognitive deficits. Building on our previous work, we sought to discover more potent neuroinflammation suppressors by designing and synthesizing a series of ar-turmerone derivatives to investigate their structure-activity relationships. Microglia-based cellular evaluations revealed that naphthyl-substituted (7c) and N-substituted amides (7a) demonstrated the most pronounced inhibitory effects against NO, TNF-α, and IL-1β release in vitro. Furthermore, in a lipopolysaccharide (LPS)-induced neuroinflammation model of Alzheimer's disease in mice, these two compounds significantly reduced proinflammatory cytokine release, protected neurons from damage, and ameliorated memory impairments and cognitive deficits in Morris water maze tests. This structural optimization of ar-turmerone yielded highly potent anti-neuroinflammatory compounds, which may serve as promising agents for the treatment of neuroinflammation-related neurodegenerative disorders.

Discovery of gallic acid-based mitochondriotropic antioxidant attenuates LPS-induced neuroinflammation

Mitochondria are complex organelle that plays a pivotal role in energy metabolism, regulation of stress responses, and also serve as a major hub for biosynthetic processes. In addition to their well-established function in cellular energetics, it also serves as the primary site for the origin of intracellular reactive oxygen species (ROS), which function as signaling molecules and can lead to oxidative stress when generated in excess. Moreover, mitochondrial dysfunction is one of the leading cause of neuroinflammation. In this regard, we have rationally designed a triazine derived mitochondriotropic antioxidants (Mito-TBA), based on gallic acid and triphenylphosphonium (TPP) cation to specifically target mitochondria to mitigate neuroinflammation. In vitro Mito-TBA-3 inhibits mitoautophagy, offers neuroprotection by inhibiting the LPS induced TLR-4 activation and activating the Nrf-2/ARE pathway in PC-12 derived neurons. In vivo Mito-TBA-3 rescue memory deficit, reversed depression like behavior, inhibited neuroinflammation, and decreased proinflammatory cytokines in LPS induced neuroinflammation rat model. Overall, based on biophysical, in vitro and in vivo analysis, Mito-TBA-3 offers valuable insights as a potent therapeutic lead molecule to combat neurodegeneration even outperforming a well-known non-steroidal anti-inflammatory drug (Aspirin), it also has the potential to use as a promising therapeutic candidate for other mitochondrial oxidative stress related disorders.

Untargeted Metabolomics Reveals Metabolic Link Between Histone H3K27 Demethylase UTX and Neurodevelopment

Ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) is a chromatin modifier responsible for regulating the demethylation of histone H3 lysine 27 trimethylation (H3K27me3), which is crucial for human neurodevelopment. To date, the impact of UTX on neurodevelopment remains elusive. Therefore, this study aimed to investigate the potential molecular mechanisms underlying the effects of UTX on neurodevelopment through untargeted metabolomics based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We found that UTX knockout in neurones leads to cell death and apoptosis in the hippocampus and cortex, as well as induces impaired learning and memory functions in mice. Moreover, UTX deletion contributed to significant metabolic perturbations in brain tissues. A total of 223 differential metabolites were identified between wild-type (WT) and UTX cKO mice. Pathway analysis indicated that the metabolic pathways mainly affected by UTX deletion were alanine, aspartate, and glutamate metabolism, resulting in significant alterations in L-alanine, L-aspartate, D-aspartate, N-acetylaspartylglutamate, L-glutamate, and argininosuccinic acid. These data emphasised that UTX may exert a key effect in neurodevelopment and that the underlying mechanism may be related to the regulation of the alanine, aspartate, and glutamate metabolism pathways, especially the characteristic metabolites involved in this pathway.

Teratological, neurochemical and histomorphic changes in the limbic areas of F1 mice progeny due to co-parental polystyrene nanoplastic exposure

In the present study, co-parental exposure to polystyrene nanoplastics (PS-NPs) elicits profound teratological impacts, including skeletal and visceral malformations, post-natal effects on neonatal growth and neurobehavioral development in F1 progeny. A comprehensive investigation was conducted on Swiss albino mice fetuses, neonates (PND 1-21) and adult mice offsprings (PND 60) following parental exposure during spermatogenesis and oogenesis period, as well as continued maternal exposure during gestation and weaning. The parental mice were administered PS-NPs via oral gavage at low dose (0.2mg/kg/day) and high dose (1mg/kg/day). Both male and female parental mice were exposed to PS-NPs for 60 days and 14 days, respectively before mating. After the mating, the pregnant female mice continued to receive PS-NPs treatment during the gestation, till the subsequent weaning period. Our findings revealed that PS-NPs led to significant reductions in growth, and heightened skeletal and visceral anomalies in developing fetuses. Exposure further impaired reflexes in neonatal mice such as grasping, surface righting and negative geotaxis. Moreover, the adult progeny also exhibited learning impairments. Neurodevelopmental assessment unveiled alterations in neurotransmitter levels, antioxidant enzyme activities, and structural changes in key limbic areas such as the cortex, hippocampus, and hypothalamus of adult mice offspring. These alterations included increased vacuolization, vascular dilation, and reduced pyramidal neurons in the hippocampus. Thus, this transgenerational study underscores the detrimental effects of PS-NPs on both prenatal and postnatal development, emphasizing teratological and enduring neurological consequences in the limbic regions of F1 progeny mice brains.

Progressive histological and behavioral deterioration of a novel mouse model of secondary hydrocephalus after subarachnoid hemorrhage

Hydrocephalus commonly occurs after subarachnoid hemorrhage (SAH) and is associated with increased morbidity and disability in patients with SAH. Choroid plexus cerebrospinal fluid (CSF) hypersecretion, obliterative arachnoiditis occluding the arachnoid villi, lymphatic obstruction, subarachnoid fibrosis, and glymphatic system injury are considered the main pathological mechanisms of hydrocephalus after SAH. Although the mechanisms of hydrocephalus after SAH are increasingly being revealed, the clinical prognosis of SAH still has not improved significantly. Further research on SAH is needed to reveal the underlying mechanisms of hydrocephalus and develop translatable therapies. A model that can stably mimic the histopathological and neuroethological features of hydrocephalus is critical for animal experiments. There have been fewer animal studies on hydrocephalus after SAH than on other stroke subtypes. The development of a reproducible and effective model of hydrocephalus after SAH is essential. In this study, we establish a mouse model of SAH that stably mimics brain injury and hydrocephalus after SAH through injections of autologous blood into the cisterna magna via different methods and characterize the model in terms of neurological behavior, histology, imaging, neuronal damage, and white matter damage.

Microcystin-LR induces neuronal damage through mitophagy defects resulted from the downregulated transcription of Scd2 by directly targeting IGF-1R

Microcystin-LR (MC-LR), a prevalent cyanotoxin present in hazardous cyanobacterial blooms, is recognized as a neurotoxic environmental pollutant that induces brain damage and neurobehavioral deficits. However, the mechanisms underlying MC-LR-induced neurotoxicity remain unclear. This study aims to elucidate the role of mitophagy in MC-LR-induced neurotoxicity both in vitro and in vivo. We found that administration of 10 μg/kg body weight (intraperitoneally) MC-LR impaired learning and memory abilities and induced neuronal damage and apoptosis in the CA1 region of the hippocampus in rats. Exposure to MC-LR (1 μM-10 μM) resulted in cellular damage and apoptosis in PC-12 and HT22 cells. MC-LR induced mitophagy through the PINK1/Parkin pathway but hindered mitophagy progression by repressing Scd2 transcription in neurons. These inhibitory effects were reversed by Scd2 overexpression. Furthermore, MC-LR was found to repress Scd2 transcription by directly binding to type 1 insulin-like growth factor receptor (IGF-1R) and competitively inhibiting its activation by Insulin-like growth factor 1 (IGF-1). Overexpression of IGF-1R and administration of exogenous IGF-1 mitigated the MC-LR-induced inhibition of Scd2 and the associated mitophagy defects. These findings indicate that IGF-1R is the direct target of MC-LR in neurons. MC-LR initiates mitophagy defects and apoptosis by inhibiting Scd2 transcription through binding to IGF-1R.

DHA Improves neurodevelopmental abnormalities in offspring of gestational diabetes mellitus patients via the PPAR-γ/FATP4 pathway

Offspring of women with gestational diabetes mellitus (GDM) face an increased risk of long-term neurodevelopmental abnormalities. This study explores the altered expression of key placental fatty acid transport proteins-FATP2, FATP4, FATP6, FABP4, and FAT/CD36-in GDM patients, and the potential of docosahexaenoic acid (DHA) to mitigate neurodevelopmental risks in offspring by enhancing their expression through activation of peroxisome proliferator-activated receptor γ (PPAR-γ). Our findings demonstrate that placental FATP4 expression is reduced in GDM patients. In HTR8/SVneo cells, PPAR-γ activation upregulated the expression of FATP4, FAT/CD36, and FABP4, while PPAR-γ inhibition only reduced FAT/CD36 expression. DHA treatment led to increased expression of FATP4, FATP/CD36 and FABP4, which was partially reversed by PPAR-γ inhibition. Consistent results were observed in an insulin-resistant cell model. Supplementing GDM mice with exogenous DHA restored placental FATP4 expression and improved offspring social behavior and cognitive function. These results suggest that DHA supplementation during pregnancy could reduce the adverse effects of GDM on placental FATP4 expression and support better neurodevelopmental outcomes in offspring by promoting essential fatty acid transport through the PPAR-γ/FATP4 pathway. This study highlights the therapeutic potential of DHA in improving fetal outcomes in GDM pregnancies.

Long-term impact of congenital Zika virus infection on the rat hippocampus: Neuroinflammatory, glial alterations and sex-specific effects

Congenital Zika Syndrome (CZS) is a condition that arises when a neonate presents with abnormalities resulting from Zika virus infection during gestation. While microcephaly is a prominent feature of the syndrome, other forms of brain damage are also observed, often accompanied by significant neurological complications. It is therefore essential to investigate the long-term effects of CZS, with special attention to sex differences, particularly concerning hippocampal function, given its vulnerability to viral infections. The aim of this study was to evaluate the long-term impacts on cognitive and memory functions, as well as neuroinflammatory and glial alterations in the hippocampus, in offspring of both sexes exposed to a model of congenital Zika virus infection. Pregnant rats were subcutaneously inoculated with ZIKV-BR at a dose of 1 × 10^7 plaque-forming units (PFU mL^-1) of ZIKV isolated in Brazil (ZIKV-BR) on gestational day 18 (G18). From postnatal day 70, the animals underwent behavioral tests. On postnatal day 80, the animals were euthanized, and hippocampal samples were collected for biochemical and histological analyses. In the open field test, females displayed more exploratory behavior and less grooming, while no significant differences in locomotion were observed between the sexes. Additionally, ZIKV-exposed females showed a reduction in grooming behavior compared to ZIKV-exposed males. In the memory test, males in the ZIKV group exhibited greater memory impairment, spending more time to locate the correct quadrant, while females showed relatively better performance. Neuroinflammatory markers, such as TNF-α, were significantly elevated in the hippocampus of ZIKV-exposed animals, regardless of sex. However, microglial and astrocytic responses, indicated by higher IBA1 and GFAP density, were only observed in male ZIKV rats. In conclusion, our findings suggest that congenital ZIKV exposure leads to sex-specific behavioral and neuroinflammatory alterations. While both males and females exhibited some behavioral changes, males were more significantly impacted in memory performance. Additionally, increased neuroinflammatory markers and glial activation were observed in the hippocampus of ZIKV-exposed animals, with a pronounced response in males. These results highlight the long-term impact of ZIKV infection on neurodevelopment, emphasizing the importance of considering sex differences in studies of congenital ZIKV syndrome.

Knockout of AMPA receptor binding protein Neuron-specific gene 2 (NSG2) enhances associative learning and cognitive flexibility

The vast majority of gene mutations and/or gene knockouts result in either no observable changes, or significant deficits in molecular, cellular, or organismal function. However, in a small number of cases, mutant animal models display enhancements in specific behaviors such as learning and memory. To date, most gene deletions shown to enhance cognitive ability generally affect a limited number of pathways such as NMDA receptor- and translation-dependent plasticity, or GABA receptor- and potassium channel-mediated inhibition. While endolysosomal trafficking of AMPA receptors is a critical mediator of synaptic plasticity, mutations in genes that affect AMPAR trafficking either have no effect or are deleterious for synaptic plasticity, learning and memory. NSG2 is one of the three-member family of Neuron-specific genes (NSG1-3), which have been shown to regulate endolysosomal trafficking of a number of proteins critical for neuronal function, including AMPAR subunits (GluA1-2). Based on these findings and the largely universal expression throughout mammalian brain, we predicted that genetic knockout of NSG2 would result in significant impairments across multiple behavioral modalities including motor, affective, and learning/memory paradigms. However, in the current study we show that loss of NSG2 had highly selective effects on associative learning and memory, leaving motor and affective behaviors intact. For instance, NSG2 KO animals performed equivalent to wild-type C57Bl/6n mice on rotarod and Catwalk motor tasks, and did not display alterations in anxiety-like behavior on open field and elevated zero maze tasks. However, NSG2 KO animals demonstrated enhanced recall in the Morris water maze, accelerated reversal learning in a touch-screen task, and accelerated acquisition and enhanced recall on a Trace Fear Conditioning task. Together, these data point to a specific involvement of NSG2 on multiple types of associative learning, and expand the repertoire of pathways that can be targeted for cognitive enhancement.

The KEAP1/PGAM5/AIFM1-Mediated oxeiptosis pathway in Alzheimer's disease

BACKGROUND

Alzheimer's Disease (AD) is a neurodegenerative disease with mitochondrial dysfunction and oxidative stress. Oxeiptosis is a cell death pathway sensitive to reactive oxygen species (ROS). This study investigates the role of oxeiptosis pathway and mitochondrial damage in AD.

METHODS

An AD model was developed in C57BL/6 mice by injecting Aβ1-42 oligomers into the brain. Cognitive function was tested using the Morris water maze. Exposure of HT22 mouse hippocampal neurons to H2O2 induces oxidative stress. Protein levels of KEAP1, PGAM5 and AIFM1 were analyzed by western blot, and mitochondrial damage was observed with electron microscopy. Cell survival rates were using the CCK8 assay and flow cytometry after knocking down KEAP1, PGAM5 and AIFM1.

RESULTS

The protein concentrations of KEAP1, PGAM5 and AIFM1 were found to be elevated in the hippocampal tissues of AD mice compared to control group, accompanied by mitochondrial damage in the hippocampal neurons of the AD group. Similarly, in the HT22 oxidative stress model, there was an increase in the protein levels of KEAP1, PGAM5 and AIFM1, along with observed mitochondrial damage. Following individual and combined knockdown of KEAP1, PGAM5 and AIFM1, cell survival rates under oxidative stress conditions were higher compared to H2O2 group, with no significant difference in cell survival rates among the knockdown groups.

CONCLUSION

This research underscores the critical role of the KEAP1/PGAM5/AIFM1-mediated oxeiptosis pathway in neuronal cell death, offering insights into potential therapeutic targets for mitigating neurodegeneration in AD.

Effective identification of Alzheimer's disease in mouse models via deep learning and motion analysis

Spatial disorientation is an early symptom of Alzheimer's disease (AD). Detecting this impairment effectively in animal models can provide valuable insights into the disease and reduce experimental burdens. We have developed a markerless motion analysis system (MMAS) using deep learning techniques for the Morris water maze test. This system allows for precise analysis of behaviors and body movements from video recordings. Using the MMAS, we identified unilateral head-turning and tail-wagging preferences in AD mice, which distinguished them from wild-type mice with greater accuracy than traditional behavioral parameters. Furthermore, the cumulative turning and wagging angles were linearly correlated with escape latency and cognitive scores, demonstrating comparable effectiveness in differentiating AD mice. These findings underscore the potential of motion analysis as an advanced method for improving the effectiveness, sensitivity, and interpretability of AD mouse identification, ultimately aiding in disease diagnosis and drug development.

Targeting Neuroinflammation and Apoptosis: Cardamonin's Cognitive Benefits in Alzheimer's 5XFAD Mice

This study aimed to evaluate the cognitive-enhancing and neuroprotective effects of cardamonin in the 5XFAD transgenic mouse model of Alzheimer's disease (AD). We treated six-month-old female 5XFAD mice with cardamonin at 5 mg/kg, 10 mg/kg, and 20 mg/kg. Cognitive function was assessed using the Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests. ELISA, western blot, and PCR analyses evaluated amyloid-beta (Aβ) levels, neuroinflammation markers, and apoptosis-related factor expression. All animals survived without toxicity. Cardamonin treatment significantly improved spatial learning and memory retention in MWM and NOR tests, with the 20 mg/kg dose showing the most pronounced effects. Additionally, cardamonin reduced soluble and insoluble Aβ levels in the frontal cortex and hippocampus. The treatment also significantly decreased neuroinflammatory markers, with IL-1β, IL-6, and TNF-α levels dropping substantially at higher doses. Cardamom treatment also normalizes cleaved caspase 3, GFAP, Iba-1, PSD-95, and synaptophysin, which aids in restoring synaptic integrity. Furthermore, cardamonin led to a marked reduction in apoptosis-related gene expression, indicating its potential to mitigate neurodegeneration. Cardamonin demonstrates significant cognitive-enhancing and neuroprotective properties in the 5XFAD mouse model, suggesting its potential as a therapeutic agent for AD. These findings support further investigation into cardamonin's mechanisms and applicability in treating neurodegenerative disorders.

LRP1-mediated p-tau propagation contributes to cognitive impairment after chronic neuropathic pain in rats

Trigeminal neuralgia (TN) is a prevalent chronic neuropathic pain syndrome characterized by severe pain, often accompanied by cognitive dysfunction and cerebral degeneration. However, its mechanisms remain poorly understood. Hyperphosphorylation of tau protein (p-tau) is often seen in neurodegenerative disorders such as Alzheimer's disease (AD). LRP1 expression on brain neurons and microglial cells is believed to facilitate the propagation of p-tau. We established a TN rat model via infraorbital nerve chronic constrictive injury (ION-CCI). Once the model was established, we investigated the association between p-tau and cognitive impairment in TN rats by evaluating behavioral and degenerative markers. During the initial phase, we noted an increase in p-tau level in the prefrontal cortex and hippocampal tissues of TN rats. The accompanied impaired learning and memory abilities suggested cognitive dysfunction. Blocking p-tau synthesis by orally administering a protein phosphatase and by injecting adenoviral vectors targeting LRP1 into the lateral ventricle of rats ameliorated cognitive impairment. This suggests that cognitive decline in TN rats is linked to elevated p-tau levels. Our findings show that LRP1-mediated p-tau propagation may drive cognitive impairment associated with neuropathic pain in TN rats.

PKM2 is a key factor to regulate neurogenesis and cognition by controlling lactate homeostasis

Adult hippocampal neurogenesis (AHN), the process of generating new neurons from adult neural stem/progenitor cells (NSPCs), is crucial for cognitive functions and is influenced by numerous factors, including metabolic processes. Pyruvate kinase M2 (PKM2), a key rate-limiting enzyme in glycolysis, catalyzes the production of pyruvate, which undergoes either oxidative phosphorylation or anaerobic oxidation. We observed that PKM2 is highly expressed in NSPCs, but its significance remains unclear for AHN and cognition. Using knockdown or knockout strategies, we discovered that PKM2 deficiency led to reduced AHN and impaired cognitive functions. Furthermore, we observed that knockout of PKM2 resulted in lower L-lactate levels, and supplementing L-lactate in PKM2 knockout mice improved AHN and cognitive functions. Mechanistically, L-lactate restored neurogenesis via monocarboxylate transporter 2 (MCT2), but not hydroxycarboxylic acid receptor 1. In summary, our findings demonstrate that PKM2 is essential for AHN, and lactate supplementation can restore neurogenesis in an MCT2-dependent manner.

Polypharmacological Drug Design Guided by Integrating Phenotypic and Restricted Fragment Docking Strategies

Polypharmacological drugs are of great value for treating complex human diseases by the combinative modulation of several biological targets. However, multitarget drug design with more than two targets is challenging and generally discovered by serendipity. Herein, a restricted fragment docking (RFD) computational method combined with a phenotypic discovery approach was developed for rational polypharmacological drug design. Via genetic and drug combination studies in a microglial phenotype, we first identified novel synergistic effects by triple target modulation toward RIPK1, MAP4K4, and ALK. Drawing on the RFD method to explore virtual chemical spaces in three target pockets, we identified a lead compound, LP-10d, that precisely modulated RIPK1/MAP4K4/ALK for synergistic microglial protection with low nanomolar potency. LP-10d showed polypharmacology against multiple neuropathologies in the 3xTg Alzheimer's disease mouse model. Our study revealed a potential application of the RFD method, which is valuable to further polypharmacological drug discovery involved in clinical studies for treating complex human diseases.

Development of coumarin-inspired bifunctional hybrids as a new class of anti-Alzheimer's agents with potent in vivo efficacy

Considering the multifactorial and complex nature of Alzheimer's disease and the requirement of an optimum multifunctional anti-Alzheimer's agent, a series of triazole tethered coumarin-eugenol hybrid molecules was designed as potential multifunctional anti-Alzheimer's agents using donepezil and a template. The designed hybrid molecules were synthesized via a click chemistry approach and preliminarily screened for cholinesterase and Aβ1-42 aggregation inhibition. Among them, AS15 emerged as a selective inhibitor of AChE (IC50 = 0.047 μM) over butyrylcholinesterase (BuChE: IC50 ≥ 10 μM) with desired Aβ1-42 aggregation inhibition (72.21% at 50 μM) properties. In addition, AS15 showed protective effects against DNA damage caused by hydroxyl radicals originating from H2O2. Molecular docking and simulation studies confirmed the favorable interactions of AChE and the Aβ1-42 monomer desired for their inhibition. AS15 exhibited an LD50 value of 300 mg kg-1 and showed significant improvements in memory and learning behavior in scopolamine-induced cognition impairment mouse-based animal models (Y-maze test and Morris water maze test) for behavioral analysis. Overall outcomes suggest AS15 as a potential preclinical multifunctional candidate for the management of Alzheimer's disease, and it serves as a promising lead for further development of potent and safer multifunctional anti-Alzheimer's agents.

Assessment of Modified Citrus Pectin's Effects on Dementia in the Scopolamine-Induced Alzheimer's Model in Adult Male Wistar Rats

Modified citrus pectin (MCP) modulates galectin-3, a key player in neuroinflammation linked to Alzheimer's disease. By inhibiting galectin-3, MCP reduces the brain's inflammatory response and may alleviate cognitive decline. This study examines MCP's impact on neuroinflammation, cognitive function, and its role in galectin-3 inhibition in a dementia model. Male Wistar rats were assigned to four groups: control (n = 6), scopolamine (SCP) (n = 7), SCP + MCP (n = 7), and MCP only (n = 7). MCP was administered orally at 100 mg/kg/day via drinking water for six weeks. SCP was injected intraperitoneally at 1 mg/kg for seven days to induce an Alzheimer's-type dementia model. The researchers assessed cognitive performance through the Morris Water Maze (MWM) test. After behavioral tests, blood and brain tissues, including the hippocampus, were collected and stored at -80 °C for analysis. Immunohistochemistry was used to evaluate superoxide dismutase (SOD) activity, malondialdehyde (MDA) levels, brain-derived neurotrophic factor (BDNF), and inflammatory markers (IL-1β, IL-6, TNF-α, and galectin-3). The data were analyzed with SPSS 22. SCP treatment increased lipid peroxidation (MDA) and elevated inflammatory markers (TNF-α, IL-6, and galectin-3), while reducing BDNF and impairing spatial memory. Co-administering MCP with SCP significantly reduced TNF-α, IL-6, and galectin-3 levels; increased BDNF; and improved memory performance. Although MCP did not lower MDA levels, it boosted SOD activity, suggesting antioxidant effects. Modified citrus pectin (MCP) alleviated cognitive impairments and reduced neuroinflammation in Alzheimer's-type dementia by inhibiting galectin-3. MCP also exhibited antioxidant potential, underscoring its therapeutic promise for neurodegenerative diseases.

A bespoke water T-maze apparatus and protocol: an optimized, reliable, and repeatable method for screening learning, memory, and executive functioning in laboratory mice

The Morris Water Maze (MWM) is the most commonly used assay for evaluating learning and memory in laboratory mice. Despite its widespread use, contemporary reviews have highlighted substantial methodological variation in experimental protocols and that the associated testing procedures are acutely (each trial) and chronically (testing across days) stressful; stress impairs attention, memory consolidation and the retrieval of learned information. Moreover, the interpretation of behavior within the MWM is often difficult because of wall hugging, non-spatial swim strategies, floating, and jumping off the escape platform. Together, these issues may compromise the reproducibility, generalizability, and predictability of experimental results, as well as animal welfare. To address these issues, and as an initial proof-of-principle, we first narrowed the spatial dimensions of the MWM by using a T-insert, which constrained and reduced the overall length of time/distance that the animal must swim in order to navigate to the escape platform, thus reducing stress and off-task behavior. Given the robust performance observed across spatial acquisition (learning and memory) as well as during reversal learning (executive function), we further reduced (by 43%) the overall distance and time that the animal must swim in order to find the escape platform in a bespoke standalone Water T-Maze (WTM). We show, across five experiments, procedural refinements to our protocol and demonstrate robust, reliable and reproducible indicators of learning, memory and executive functioning in a task that is also significantly more efficient (3 days of testing within the WTM vs. 11 days of testing within the MWM). Taken together, our WTM apparatus and protocol are a significant improvement over other water-based apparatuses and protocols for evaluating learning, memory, and executive functioning in laboratory mice.

The deacetylase SIRT6 reduces amyloid pathology and supports cognition in mice by reducing the stability of APP in neurons

Alzheimer's disease (AD) is an aging-related neurodegenerative disorder that results in progressively impaired memory and is often associated with amyloid plaques. Previous studies implicate the deacetylases SIRT1 and SIRT2 in regulating the processing of amyloid precursor protein (APP). Here, we investigated whether APP is regulated by the related deacetylase SIRT6, which shows aging-associated decreases in activity. We found that the abundance of SIRT6 was reduced in the cortex and hippocampus of aged and AD model mice and negatively correlated with that of APP. In mouse hippocampal neurons and transfected human cells, SIRT6 interacted with and deacetylated APP at three consecutive Lys residues (Lys649, Lys650, and Lys651). This deacetylation, in turn, increased the ubiquitylation of APP, leading to its proteasomal degradation. SIRT6 abundance in neurons was reduced by oxidative stress and DNA damage, both of which are implicated in neurodegenerative pathology. Systemic pharmacological activation of SIRT6 ameliorated both amyloid pathology and cognitive deficits in APP/PS1 mice, a mouse model of AD. The findings demonstrate that the activity of SIRT6 destabilizes APP and suggest that activating SIRT6 has therapeutic potential to reduce amyloid-associated pathology in patients with AD.

Cis-Regulatory Evolution of CCNB1IP1 Driving Gradual Increase of Cortical Size and Folding in primates

Neocortex expansion has a concerted relationship with folding, underlying evolution of human cognitive functions. However, molecular mechanisms underlying this significant evolutionary process remains unknown. Here, using tree shrew as an outgroup of primates, we identify a new regulator CCNB1IP1, which acquired its expression before the emergence of primates. Following the evolution of cis-regulatory elements, the CCNB1IP1 expression has steadily increased over the course of primate brain evolution, mirroring the gradual increase of neocortex. Mechanistically, we elucidated that CCNB1IP1 expression can cause an increase in neural progenitors through shortening G1 phase. Consistently, the CCNB1IP1 knock-in mouse model exhibited traits associated with enhanced learning and memory abilities. Together, our study reveals how changes in CCNB1IP1 expression may have contributed to the gradual evolution in primate brain.