BDNF and memory processing

Inhibition of 5-HT alleviates PTSD-like behaviors and promotes hippocampal neuroplasticity by modulating hippocampal autophagy in rats

5-Hydroxytryptamine (5-HT) plays a substantial role in mitigating depression and anxiety. However, the potential effects of 5-HT against posttraumatic stress disorder (PTSD) and its underlying mechanisms remain unclear. Elevated plus maze test evaluates anxiety-related behaviors, and the open field test is used to assess overall activity levels and anxiety. Inflammatory cytokine levels were determined using ELISA. The levels of 5-HT and dopamine were measured using HPLC. mRNA and protein levels were examined by PCR and Western blot, respectively. Rats exposed to single prolonged stress (SPS) exhibited typical PTSD-like phenotypes, with decreased levels of 5-HT in the hippocampus and significant reductions in its downstream targets, brain-derived neurotrophic factor (BDNF) and TrkB. In addition, it was discovered that the autophagy signaling pathway might be involved in regulating hippocampal BDNF in rats exposed to SPS. Subsequent treatment with an intracerebral injection of sh-SERT significantly inhibited anxiety and cognitive dysfunction in rats. Moreover, sh-SERT treatment was observed to substantially reverse the increase in autophagy signaling protein expression and consequently improve the expression of BDNF and TrkB proteins, which had been reduced. The current study demonstrates that sh-SERT exhibits significant anti-PTSD effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.NEW & NOTEWORTHY The study demonstrated that sh-SERT exhibits significant anti-posttraumatic stress disorder (PTSD) effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.

Investigation of the relationship between neuroplasticity and grapheme-color synesthesia

Grapheme-color synesthesia is a normal and healthy variation of human perception. It is characterized by the association of letters or numbers with color perceptions. The etiology of synesthesia is not yet fully understood. Theories include hyperconnectivity in the brain, cross-activation of adjacent or functionally proximate sensory areas of the brain, or various models of lack of inhibitory function in the brain. The growth factor brain-derived neurotrophic (BDNF) plays an important role in the development of neurons, neuronal pathways, and synapses, as well as in the protection of existing neurons in both the central and peripheral nervous systems. ELISA methods were used to compare BDNF serum concentrations between healthy test subjects with and without grapheme-color synesthesia to establish a connection between concentration and the occurrence of synesthesia. The results showed that grapheme-color synesthetes had an increased BDNF serum level compared to the matched control group. Increased levels of BDNF can enhance the brain's ability to adapt to changing environmental conditions, injuries, or experiences, resulting in positive effects. It is discussed whether the integration of sensory information is associated with or results from increased neuroplasticity. The parallels between neurodegeneration and brain regeneration lead to the conclusion that synesthesia, in the sense of an advanced state of consciousness, is in some cases a more differentiated development of the brain rather than a relic of early childhood.

Mixing energy drinks and alcohol during adolescence impairs brain function: A study of rat hippocampal plasticity

In the last decades, the consumption of energy drinks has risen dramatically, especially among young people, adolescents and athletes, driven by the constant search for ergogenic effects, such as the increase in physical and cognitive performance. In parallel, mixed consumption of energy drinks and ethanol, under a binge drinking modality, under a binge drinking modality, has similarly grown among adolescents. However, little is known whether the combined consumption of these drinks, during adolescence, may have long-term effects on central function, raising the question of the risks of this habit on brain maturation. Our study was designed to evaluate, by behavioral, electrophysiological and molecular approaches, the long-term effects on hippocampal plasticity of ethanol (EtOH), energy drinks (EDs), or alcohol mixed with energy drinks (AMED) in a rat model of binge-like drinking adolescent administration. The results show that AMED binge-like administration produces adaptive hippocampal changes at the molecular level, associated with electrophysiological and behavioral alterations, which develop during the adolescence and are still detectable in adult animals. Overall, the study indicates that binge-like drinking AMED adolescent exposure represents a habit that may affect permanently hippocampal plasticity.

Enhancement of response learning in male rats with intrastriatal infusions of a BDNF - TrkB agonist, 7,8-dihydroxyflavone

Enhancement of learning and memory by cognitive and physical exercise may be mediated by brain-derived neurotrophic factor (BDNF) acting at tropomyosin receptor kinase B (TrkB). Upregulation of BDNF and systemic administration of a TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF), enhance learning of several hippocampus-sensitive tasks in rodents. Although BDNF and 7,8-DHF enhance functions of other brain areas too, these effects have mainly targeted non-cognitive functions. One goal of the present study was to determine whether 7,8-DHF would act beyond the hippocampus to enhance cognitive functions sensitive to manipulations of the striatum. Here, we examined the effects of intrastriatal infusions of 7,8-DHF on learning a striatum-sensitive response maze and on phosphorylation of TrkB receptors in 3-month-old male Sprague Dawley rats. Most prior studies of BDNF and 7,8-DHF effects on learning and memory have administered the drugs for days to months before assessing effects on cognition. A second goal of the present study was to determine whether a single drug treatment near the time of training would effectively enhance learning. Moreover, 7,8-DHF is often tested for its ability to reverse impairments in learning and memory rather than to enhance these functions in the absence of impairments. Thus, a third goal of this experiment was to evaluate the efficacy of 7,8-DHF in enhancing learning in unimpaired rats. In untrained rats, intrastriatal infusions of 7,8-DHF resulted in phosphorylation of TrkB receptors, suggesting that 7,8-DHF acted as a TrkB agonist and BDNF mimic. The findings that a single, intra-striatal infusion of 7,8-DHF 20 min before training enhanced response learning in rats suggest that, in addition to its trophic effects, BDNF modulates learning and memory through receptor mediated cell signaling events.

Sex as a Determinant of Age-Related Changes in the Brain

The notion of notable anatomical, biochemical, and behavioral distinctions within male and female brains has been a contentious topic of interest within the scientific community over several decades. Advancements in neuroimaging and molecular biological techniques have increasingly elucidated common mechanisms characterizing brain aging while also revealing disparities between sexes in these processes. Variations in cognitive functions; susceptibility to and progression of neurodegenerative conditions, notably Alzheimer's and Parkinson's diseases; and notable disparities in life expectancy between sexes, underscore the significance of evaluating aging within the framework of gender differences. This comprehensive review surveys contemporary literature on the restructuring of brain structures and fundamental processes unfolding in the aging brain at cellular and molecular levels, with a focus on gender distinctions. Additionally, the review delves into age-related cognitive alterations, exploring factors influencing the acceleration or deceleration of aging, with particular attention to estrogen's hormonal support of the central nervous system.

Virtual realities, real recoveries: exploring the efficacy of 3MDR therapy for treatment-resistant PTSD

Exposure-based therapies have shown promise in treating post-traumatic stress disorder (PTSD), but challenges exist in maintaining patient engagement and finding appropriate stimuli for graded exposure. Virtual reality (VR) technology has been used to enhance exposure therapy, but current software lacks customization and some patients remain treatment-resistant. A novel approach called multimodular motion-assisted memory desensitization and reconsolidation (3MDR) has the potential to solve some of the current limitations of VR-assisted exposure therapy. This study examines the efficacy of 3MDR treatment for individuals with treatment-resistant PTSD through a systematic review of relevant literature and clinical studies. Preliminary findings indicate promise for 3MDR in reducing PTSD symptoms, including emotional regulation and moral injury. However, further research with larger samples and controlled studies is needed to understand underlying mechanisms and validate these results. Moreover, this study highlights the importance of health-economic evaluations to assess costs and resource utilization associated with implementing 3MDR treatment in clinical services.

Hesperidin neuroprotective effects against carbon monoxide-induced toxicity in male rats

Carbon monoxide (CO) is produced via incomplete combustion of fossil fuels and it may cause long-term neurological sequel upon exposure. Hesperidin (HES), a flavanone glycoside found in citrus plants, exerts diverse beneficial health effects. The present study mechanistically examined the neuroprotective effects of HES in CO-poisoned rats. Thirty male Wistar rats (five groups of six animals) were exposed to 3000 ppm CO for 1 h. Immediately after the exposure and on the next 4 consecutive days (totally five doses), rats intraperitoneally received either normal saline (the control group) or different doses of HES (25, 50, and 100 mg/kg). A sham group that was not exposed to CO was also considered. After evaluation of spatial learning and memory using a Morris water maze (MWM), animals were sacrificed and oxidative stress status in blood samples, and Akt, Bax, Bcl2, and brain-derived neurotrophic factor (BDNF) expression in brain samples were assessed. Western blot analysis indicated increased Akt but decreased Bax/Bcl2 levels in the HES 100 mg/kg, and induced BDNF levels in all HES-treated groups. MWM results showed that HES significantly decreased memory loss. The current findings indicate that HES could alleviate neurological impairments induced by CO in rats.

BDNF Signaling in Vascular Dementia and Its Effects on Cerebrovascular Dysfunction, Synaptic Plasticity, and Cholinergic System Abnormality

Vascular dementia (VaD) is the second most common type of dementia and is characterized by memory impairment, blood-brain barrier disruption, neuronal cell loss, glia activation, impaired synaptic plasticity, and cholinergic system abnormalities. To effectively prevent and treat VaD a good understanding of the mechanisms underlying its neuropathology is needed. Brain-derived neurotrophic factor (BDNF) is an important neurotrophic factor with multiple functions in the systemic circulation and the central nervous system and is known to regulate neuronal cell survival, synaptic formation, glia activation, and cognitive decline. Recent studies indicate that when compared with normal subjects, patients with VaD have low serum BDNF levels and that BDNF deficiency in the serum and cerebrospinal fluid is an important indicator of VaD. Here, we review current knowledge on the role of BDNF signaling in the pathology of VaD, such as cerebrovascular dysfunction, synaptic dysfunction, and cholinergic system impairment.

Sildenafil prevents chronic psychosocial stress-induced working memory impairment: Role of brain-derived neurotrophic factor

Background

Psychosocial stress, a common feature in modern societies, impairs cognitive functions. It is suggested that stress hormones and elevated excitatory amino acids during stress are responsible for stress-induced cognitive deficits. Reduced brain-derived neurotrophic factor (BDNF) levels, increased oxidative stress, and alteration of synaptic plasticity biomarkers are also possible contributors to the negative impact of stress on learning and memory. Sildenafil citrate is a selective phosphodiesterase type 5 (PDE5) inhibitor and the first oral therapy for the treatment of erectile dysfunction. It has been shown that sildenafil improves learning and memory and possesses antioxidant properties. We hypothesized that administering sildenafil to stressed rats prevents the cognitive deficit induced by chronic psychosocial stress.

Methods

Psychosocial stress was generated using the intruder model. Sildenafil 3 mg/kg/day was administered intraperitoneally to animals. Behavioral studies were conducted to test spatial learning and memory using the radial arm water maze. Then, the hippocampal BDNF level and several antioxidant markers were assessed.

Results

This study revealed that chronic psychosocial stress impaired short-term but not long-term memory. The administration of sildenafil prevented this short-term memory impairment. Chronic psychosocial stress markedly reduced the level of hippocampal BDNF (P˂0.05), and this reduction in BDNF was normalized by sildenafil treatment. In addition, neither chronic psychosocial stress nor sildenafil significantly altered the activity of measured oxidative parameters (P > 0.05).

Conclusion

Chronic psychosocial stress induces short-term memory impairment. The administration of sildenafil citrate prevented this impairment, possibly by normalizing the level of BDNF.

Conditioned morphine tolerance promotes neurogenesis, dendritic remodelling and pro-plasticity molecules in the adult rat hippocampus

Structural neuroplasticity of the hippocampus in the form of neurogenesis and dendritic remodelling underlying morphine tolerance is still less known. Therefore, in this study, we aimed to assess whether unconditioned- and conditioned-morphine tolerance can trigger structural neuroplasticity in the dorsal and ventral parts of the adult male rat hippocampus. Evaluation of the levels of neurogenesis markers (Ki67 and DCX) by immunohistochemistry shows that conditioned morphine tolerance is sufficient to increase the baseline topographic level of hippocampal neurogenesis in adult rats. Dendritic spine visualization by Golgi staining shows that the behavioural testing paradigms themselves are sufficient to trigger the hippocampus subregion-specific changes in the dendritic remodelling along the apical dendrites of hippocampal CA1 pyramidal neurons and dentate granule cells in adult rats. Quantitative reverse transcription polymerase chain reaction of Bdnf, Trkb, Rac-1 and RhoA mRNA levels as pro-plasticity molecules, shows that the conditioned morphine tolerance is effective in changing Bdnf and RhoA mRNA levels in the ventral hippocampus of adult rats. In summary, we demonstrate that the acquisition of morphine tolerance promotes adult neurogenesis, dendritic remodelling and pro-plasticity molecules such as Bdnf/Trkb in the rat hippocampus. Indeed, the structural neuroplasticity of the hippocampus may underlie the newly formed aberrant memory and could provide the initial basis for understanding the neurobiological mechanisms of morphine-tolerance plasticity in the hippocampus.

The Effect of Aerobic Exercise in Neuroplasticity, Learning, and Cognition: A Systematic Review

This systematic review aims to examine the association between physical activity, neuroplasticity, and cognition. We analyzed an initial dataset consisting of 9935 articles retrieved from three scientific platforms (PubMed, Scopus, and the Virtual Health Library). Various screening filters were applied to refine the information against predefined eligibility criteria, resulting in the inclusion of a total of 17 articles that assessed the effect of aerobic exercise on neuroplasticity. The results suggested that aerobic exercise at various intensities, particularly at high intensity, can influence cortical excitability and result in cognitive improvement; also, exercise was associated with direct cortical and structural changes. Exercise has shown efficacy in individuals of diverse age groups, as well as in people with and without brain disease.

Impaired synaptic plasticity and decreased excitability of hippocampal glutamatergic neurons mediated by BDNF downregulation contribute to cognitive dysfunction in mice induced by repeated neonatal exposure to ketamine

AIM

Repeated exposure to ketamine during the neonatal period in mice leads to cognitive impairments in adulthood. These impairments are likely caused by synaptic plasticity and excitability damage. We investigated the precise role of brain-derived neurotrophic factor (BDNF) in the cognitive impairments induced by repeated ketamine exposure during the neonatal period.

METHODS

We evaluated the cognitive function of mice using the Morris water maze test and novel object recognition test. Western blotting and immunofluorescence were used to detect the protein levels of BDNF. Western blotting, Golgi-Cox staining, transmission electron microscopy, and long-term potentiation (LTP) recordings were used to assess synaptic plasticity in the hippocampus. The excitability of neurons was evaluated using c-Fos. In the intervention experiment, pAdeno-CaMKIIα-BDNF-mNeuronGreen was injected into the hippocampal CA1 region of mice to increase the level of BDNF. The excitability of neurons was enhanced using a chemogenetic approach.

RESULTS

Our findings suggest that cognitive impairments in mice repeatedly exposed to ketamine during the neonatal period are associated with downregulated BDNF protein level, synaptic plasticity damage, and decreased excitability of glutamatergic neurons in the hippocampal CA1 region. Furthermore, the specific upregulation of BDNF in glutamatergic neurons of the hippocampal CA1 region and the enhancement of excitability can improve impaired synaptic plasticity and cognitive function in mice.

CONCLUSION

BDNF downregulation mediates synaptic plasticity and excitability damage, leading to cognitive impairments in adulthood following repeated ketamine exposure during the neonatal period.

BDNF-dependent signaling in the olfactory bulb modulates social recognition memory in mice

An operative olfactory bulb (OB) is critical to social recognition memory (SRM) in rodents, which involves identifying conspecifics. Furthermore, OB also allocates synaptic plasticity events related to olfactory memories in their intricate neural circuit. Here, we asked whether the OB is a target for brain-derived neurotrophic factor (BDNF), a well-known mediator of plasticity and memory. Adult ICR-CD1 male mice had their SRM evaluated under the inhibition of BDNF-dependent signaling directly in the OB. We also quantified the expression of BDNF in the OB, after SRM acquisition. Our results presented an amnesic effect of anti-BDNF administered 12 h post-training. Although the western blot showed no statistical difference in pro-BDNF and BDNF expression, the analysis of fluorescence intensity in slices suggests SRM acquisition decreases BDNF in the granular cell layer of the OB. Next, to test the ability of BDNF to rescue SRM deficit, we administered the human recombinant BDNF (rBDNF) directly in the OB of socially isolated (SI) mice. Unexpectedly, rBDNF did not rescue SRM in SI mice. Furthermore, BDNF and pro-BDNF expression in the OB was unchanged by SI. Our study reinforces the OB as a plasticity locus in memory-related events. It also adds SRM as another type of memory sensitive to BDNF-dependent signaling.

Potential of piperine for neuroprotection in sepsis-associated encephalopathy

AIMS

Sepsis-associated encephalopathy (SAE) is a common complication that increases mortality and leads to long-term cognitive impairment in sepsis survivors. However, no specific or effective therapy has been identified for this complication. Piperine is an alkaloid known for its anti-inflammatory, antioxidant, and neuroprotective properties, which are important characteristics for treatment of SAE. The objective of this study was to evaluate the neuroprotective effect of piperine on SAE in C57BL/6 mice that underwent cecum ligation and perforation surgery (CLP).

MAIN METHODS

C57BL/6 male mice were randomly assigned to groups that underwent SHAM surgery or CLP. Mice in the CLP group were treated with piperine at doses of 20 or 40 mg/kg for short- (5 days) or long-term (10 days) periods after CLP.

KEY FINDINGS

Our results revealed that untreated septic animals exhibited increased concentrations of IL-6, TNF, VEGF, MMP-9, TBARS, and NLRP3, and decreased levels of BDNF, sulfhydryl groups, and catalase in the short term. Additionally, the levels of carbonylated proteins and degenerated neuronal cells were increased at both time points. Furthermore, short-term and visuospatial memories were impaired. Piperine treatment reduced MMP-9 activity in the short term and decreased the levels of carbonylated proteins and degenerated neuronal cells in the long term. It also lowered IL-6 and TBARS levels at both time points evaluated. Moreover, piperine increased short-term catalase and long-term BDNF factor levels and improved memory at both time points.

SIGNIFICANCE

In conclusion, our data demonstrate that piperine exerts a neuroprotective effect on SAE in animals that have undergone CLP.

Neurotrophin growth factors and their receptors as promising blood biomarkers for Alzheimer's Disease: a gene expression analysis study

BACKGROUND

Alzheimer's disease (AD) is a multifaceted neurological ailment affecting more than 50 million individuals globally, distinguished by a deterioration in memory and cognitive abilities. Investigating neurotrophin growth factors could offer significant contributions to understanding AD progression and prospective therapeutic interventions.

METHODS AND RESULTS

The present investigation collected blood samples from 50 patients diagnosed with AD and 50 healthy individuals serving as controls. The mRNA expression levels of neurotrophin growth factors and their receptors were measured using quantitative PCR. A Bayesian regression model was used in the research to assess the relationship between gene expression levels and demographic characteristics such as age and gender. The correlations between variables were analyzed using Spearman correlation coefficients, and the diagnostic potential was assessed using a Receiver Operating Characteristic curve. NTRK2, TrkA, TrkC, and BDNF expression levels were found to be considerably lower (p-value < 0.05) in the blood samples of AD patients compared to the control group. The expression of BDNF exhibited the most substantial decrease in comparison to other neurotrophin growth factors. Correlation analysis indicates a statistically significant positive association between the genes. The ROC analysis showed that BDNF exhibited the greatest Area Under the Curve (AUC) value of 0.76, accompanied by a sensitivity of 70% and specificity of 66%. TrkC, TrkA, and NTRK2 demonstrated considerable diagnostic potential in distinguishing between cases and controls.

CONCLUSION

The observed decrease in the expression levels of NTRK2, TrkA, TrkC, and BDNF in AD patients, along with the identified associations between specific genes and their diagnostic capacity, indicate that these expressions have the potential to function as biomarkers for the diagnosis and treatment of AD.

Learning induces EPO/EPOr expression in memory relevant brain areas, whereas exogenously applied EPO promotes remote memory consolidation

Memory and learning allow animals to appropriate certain properties of nature with which they can navigate in it successfully. Memory is acquired slowly and consists of two major phases, a fragile early phase (short-term memory, <4 h) and a more robust and long-lasting late one (long-term memory, >4 h). Erythropoietin (EPO) prolongs memory from 24 to 72 h when animals are trained for 5 min in a place recognition task but not when training lasted 3 min (short-term memory). It is not known whether it promotes the formation of remote memory (≥21 days). We address whether the systemic administration of EPO can convert a short-term memory into a long-term remote memory, and the neural plasticity mechanisms involved. We evaluated the effect of training duration (3 or 5 min) on the expression of endogenous EPO and its receptor to shed light on the role of EPO in coordinating mechanisms of neural plasticity using a single-trial spatial learning test. We administered EPO 10 min post-training and evaluated memory after 24 h, 96 h, 15 days, or 21 days. We also determined the effect of EPO administered 10 min after training on the expression of arc and bdnf during retrieval at 24 h and 21 days. Data show that learning induces EPO/EPOr expression increase linked to memory extent, exogenous EPO prolongs memory up to 21 days; and prefrontal cortex bdnf expression at 24 h and in the hippocampus at 21 days, whereas arc expression increases at 21 days in the hippocampus and prefrontal cortex.

Early macrophage-mediated Bdnf expression in white adipose tissue during high-fat diet feeding

The expression of brain-derived neurotrophic factor (BDNF) is observed not only in the brain, but also in peripheral tissues including white adipose tissues (WATs). Here, we showed that the mRNA expression of Bdnf in inguinal WAT (iWAT) and epididymal WAT (eWAT) increased within 2 weeks of feeding mice with a high-fat diet (HFD). In mice on a 2-week HFD, the induction of Bdnf expression in WATs was significantly correlated with increases in body weight, suggesting that Bdnf expression may increase at an early stage of obesity. The mRNA expression of hypoxia-inducible factor 1α and platelet-derived growth factor, which are involved in neovascularization and the subsequent expansion of adipose tissues, increased in the iWAT of mice on the 2-week HFD. We also found that the expression of macrophage marker F4/80 in iWAT increased under the HFD. Interestingly, HFD-induced Bdnf expression in iWAT was not observed when macrophages were removed by the administration of clodronate liposomes. Accordingly, mice receiving clodronate liposomes also exhibited a significant reduction in the HFD-induced increase in body weight. In conclusion, increased body weight in HFD-induced obese model mice was accompanied by the induction of Bdnf expression in iWAT and was probably mediated by macrophages. Our findings imply a novel function for BDNF in iWAT at an early stage of obesity.

The Post-conditioning Acute Strength Exercise Facilitates Contextual Fear Memory Consolidation Via Hippocampal N-methyl-D-aspartate-receptors

The benefits of aerobic exercises for memory are known, but studies of strength training on memory consolidation are still scarce. Exercise stimulates the release of metabolites and myokines that reaching the brain stimulate the activation of NMDA-receptors and associated pathways related to cognition and synaptic plasticity. The aim of the present study was to investigate whether the acute strength exercise could promote the consolidation of a weak memory. We also investigated whether the effects of strength exercise on memory consolidation and on the BDNF and synapsin I levels depends on the activation of NMDA-receptors. Male Wistar rats were submitted to strength exercise session after a weak training in contextual fear conditioning paradigm to investigate the induction of memory consolidation. To investigate the participation of NMDA-receptors animals were submitted to contextual fear training and strength exercise and infused with MK801 or saline immediately after exercise. To investigate the participation of NMDA-receptors in BDNF and synapsin I levels the animals were submitted to acute strength exercise and infused with MK801 or saline immediately after exercise (in absence of behavior experiment). Results showed that exercise induced the consolidation of a weak memory and this effect was dependent on the activation of NMDA-receptors. The hippocampal overexpression of BDNF and Synapsin I through exercise where NMDA-receptors dependent. Our findings showed that strength exercise strengthened fear memory consolidation and modulates the overexpression of BDNF and synapsin I through the activation of NMDA-receptors dependent signaling pathways.

Exercise to prevent the negative effects of sleep deprivation: A systematic review and meta-analysis

Ample sleep is an important basis for maintaining health, however with the pace of life accelerating in modern society, more people are using sacrificial sleep to cope with these social changes. Sleep deprivation can have negative effects on cognitive performance and psychosomatic health. It is well known that exercise, as a beneficial intervention strategy for human health, has been increasingly used in the clinic. But it's not clear if it can prevent the negative effects of sleep deprivation. In this meta-analysis, we reviewed 23 articles from PubMed and Web of Science to investigate whether moderate physical exercise can prevent the negative effects of sleep deprivation in rodents. Our findings suggest that exercise can prevent sleep deprivation-induced cognitive impairment and anxiety-like behaviors through multiple pathways. We also discuss possible molecular mechanisms involved in this protective effect, highlighting the potential of exercise as a preventive or therapeutic strategy for sleep deprivation-induced negative effects.

A circadian rhythm-restricted diet regulates autophagy to improve cognitive function and prolong lifespan

Diet and circadian rhythms have been found to have a profound impact on health, disease, and aging. Skipping breakfast, eating late, and overeating have adverse effects on the body's metabolism and increase the risk of cardiovascular and metabolic diseases. Disturbance of circadian rhythms has been associated with increased risk of atherosclerosis, Alzheimer's disease, Parkinson's disease, and other diseases. Abnormal deposition of amyloid β (Aβ) and tau proteins in the brain and impaired synaptic function are linked to cognitive dysfunction. A restrictive diet following the circadian rhythm can affect the metabolism of lipids, glucose, and amino acids such as branched chain amino acids and cysteine. These metabolic changes contribute to autophagy through molecular mechanisms such as adenosine monophosphate-activated protein kinase (AMPK), rapamycin (mTOR), D-β-hydroxybutyrate (D-BHB), and neuropeptide Y (NPY). Autophagy, in turn, promotes the removal of abnormally deposited proteins and damaged organelles and improves cognitive function, ultimately prolonging lifespan. In addition, a diet restricted to the circadian rhythm induces increased expression of brain-derived neurotrophic factor (BDNF) in the forebrain region, regulating autophagy and increasing synaptic plasticity, thus enhancing cognitive function. Consequently, circadian rhythm-restricted diets could serve as a promising non-pharmacological treatment for preventing and improving cognitive dysfunction and prolonging lifespan.

Exploring the mRNA and Plasma Protein Levels of BDNF, NT4, SIRT1, HSP27, and HSP70 in Multiple Sclerosis Patients and Healthy Controls

Multiple sclerosis (MS) is a chronic, autoimmune neurodegenerative disease affecting the central nervous system. It is a major cause of non-traumatic neurological disability among young adults in North America and Europe. This study focuses on neuroprotective genes (BDNF, NT4/5, SIRT1, HSP70, and HSP27). Gene expression and protein levels of these markers were compared between MS patients and healthy controls. Blood samples were collected from 42 patients with multiple sclerosis (MS) and 48 control subjects without MS. Quantitative real-time PCR was performed to measure the expression of specific genes. The samples were analyzed in duplicate, and the abundance of mRNA was quantified using the 2-ΔCt method. ELISA assay was used to measure the concentration of specific proteins in the plasma samples. The results show that a 3.5-fold decrease in the gene expression of BDNF corresponds to a 1.5-fold downregulation in the associated plasma protein concentration (p < 0.001). Similar trends were observed with NT-4 (five-fold decrease, slight elevation in protein), SIRT1 (two-fold decrease, two-fold protein decrease), HSP70 (four-fold increase, nearly two-fold protein increase), and HSP27 (four-fold increase, two-fold protein increase) (p < 0.001). This study reveals strong correlations between gene expression and protein concentration in MS patients, emphasizing the relevance of these neuroprotective markers in the disease.

Alterations of learning and memory are accompanied by alterations in the expression of 5-HT receptors, glucocorticoid receptor and brain-derived neurotrophic factor in different brain regions of an animal model of depression generated by neonatally male treatment with clomipramine in male rats

Depressive illness has been associated with impaired cognitive processes accompanied by reduced neurotrophin levels, especially brain-derived neurotrophic factor (BDNF), and dysfunctions in the hypothalamic-pituitary-adrenal (HPA) axis. In addition, depression is characterized by a decreased functioning of the serotonergic system due to changes in the activity or expression of its receptors including, most significantly, 5-HT1A, 5-HT2A, and 5-HT3 in brain regions that regulate mood, emotions, and memory, such as the prefrontal cortex, hippocampus, and amygdala. In this regard, rats treated with clomipramine (CMI) in the neonatal stage show depression-like behaviors that persist into adulthood; hence, this constitutes an adequate model of depression for exploring various molecular aspects associated with the etiology of this disorder. This, study, then, was designed to analyze the long-term effects of early postnatal exposure to CMI on the expression of 5-HT1A, 5-HT2A, and 5-HT3 receptors, as well as BDNF and GR in the following brain regions: PFC, amygdala, hippocampus, and hypothalamus, which could be related to alterations in memory and learning, as evaluated using the novel object recognition (NOR) and Morris water maze (MWM). Expression of the 5-HT1A, 5-HT2A, and 5-HT3 receptors, BDNF, and the glucocorticoid receptor (GR) was assessed by RT-qPCR in the four aforementioned brain regions, all of which play important roles in the control of memory and mood. Findings show that neonatal treatment with CMI causes alterations in memory and learning, as indicated by alterations in the results of the MWM and NOR tests. Expression of the 5-HT1A receptor increased in the hippocampus, amygdala, and hypothalamus, but decreased in the PFC, while the 5-HT2A and BDNF receptors decreased their expression in the PFC, amygdala, and hippocampus. There was no change in the expression of the 5-HT3 receptor. In addition, expression of GR in the hippocampus and PFC was low, but increased in the hypothalamus. Taken together, these data show that neonatal CMI treatment produces permanent molecular changes in brain regions related to learning and memory that could contribute to explaining the behavioral alterations observed in this model.

Correlation between nocturnal intermittent hypoxemia and mild cognitive impairment in the older adult and the role of BDNF Val66Met polymorphism: a hospital-based cross-sectional study

PURPOSE

To explore the prevalence of nocturnal intermittent hypoxemia (NIH) in a tertiary hospital geriatric department and the relationship between NIH and mild cognitive impairment (MCI) in older adults, and to examine the role of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism.

METHODS

Older adults aged ≥ 60 were enrolled. NIH and cognitive assessments were conducted. BDNF concentrations and BDNF Val66Met polymorphism were detected for a preliminary exploration of the possible mechanism of the process.

RESULTS

Of 325 older adults enrolled, 157 (48%) had NIH and were further divided into mild, moderate, and severe NIH groups according to their oxygen desaturation of ≥ 4% per hour of sleep (ODI4). MCI detection rate in the four groups gradually increased, and the differences were statistically significant (chi-square = 4.457, P = 0.035). ODI4 was negatively correlated with MoCA score in all participants (r =  - 0.115, P = 0.039) and patients with NIH (r =  - 0.199, P = 0.012). After adjusting for sex, age, and cardiovascular risk factors, NIH and MCI remained independently associated (OR = 3.13, 95% CI 1.03-9.53, P = 0.045). BDNF levels were positively correlated with MoCA score (r = 0.169, P = 0.028) and negatively correlated with nocturnal average oxygen saturation in patients with NIH (r =  - 0.288, P = 0.008). Older adults with different BDNF Val66Met genotypes did not show significant differences in MCI rate and BDNF levels (P > 0.05).

CONCLUSION

The older adults with NIH have a higher MCI detection rate. BDNF levels may be a potential biomarker for cognitive dysfunction in patients with NIH.

Beta-caryophyllene mitigates the cognitive impairment caused by repeated exposure to aspartame in rats: Putative role of BDNF-TrKB signaling pathway and acetylcholinesterase activity

Aspartame (ASP) is a common sweetener, but studies show it can harm the nervous system, causing learning and memory deficits. β-caryophyllene (BCP), a natural compound found in foods, including bread, coffee, alcoholic beverages, and spices, has already described as a neuroprotector agent. Remarkably, ASP and BCP are commonly consumed, including in the same meal. Therefore, considering that (a) the BCP displays plenty of beneficial effects; (b) the ASP toxicity; and (c) that they can be consumed in the same meal, this study sought to investigate if the BCP would mitigate the memory impairment induced by ASP in rats and investigate the involvement of the brain-derived neurotrophic factor (BDNF)/ tropomyosin receptor kinase B (TrKB) signaling pathway and acetylcholinesterase (AChE) activity. Young male Wistar rats received ASP (75 mg/kg; i.g.) and/or BCP (100 mg/kg; i.p.) once daily, for 14 days. At the end of the treatment, the animals were evaluated in the open field and object recognition tests. The cerebral cortex and hippocampus samples were collected for biochemical and molecular analyses. Results showed that the BCP effectively protected against the cognitive damage caused by ASP in short and long-term memories. In addition, BCP mitigated the increase in AChE activity caused by ASP. Molecular insights revealed augmented BDNF and TrKB levels in the hippocampus of rats treated with BCP, indicating greater activation of this pathway. In conclusion, BCP protected against ASP-induced memory impairment. AChE activity and the BDNF/TrkB signaling pathway seem to be potential targets of BCP modulatory role in this study.

Fructooligosaccharide (FOS) and Galactooligosaccharide (GOS) Improve Neuroinflammation and Cognition By Up-regulating IRS/PI3K/AKT Signaling Pathway in Diet-induced Obese Mice

Increasing evidence has indicated that prebiotics as an alternative treatment for neuropsychiatric diseases. This study evaluated the prebiotics Fructooligosaccharides (FOS) and Galactooligosaccharides (GOS) on the modulation of neuroinflammation and cognition in an experimental model of mice high-fat diet fed. Initially, mice were distributed in the following groups: (A) control standard diet (n = 15) and (B) HFD for 18 weeks (n = 30). In the 13th week, the mice were later divided into the following experimental groups: (A) Control (n = 15); (B) HFD (n = 14); and (C) HFD + Prebiotics (n = 14). From the 13th week, the HFD + Prebiotics group received a high-fat diet and a combination of FOS and GOS. In the 18th week, all animals performed the T-maze and Barnes Maze, and were later euthanized. Biochemical and molecular analyzes were performed to assess neuroinflammation, neurogenesis, synaptic plasticity, and intestinal inflammation. Mice fed HFD had higher blood glucose, triglyceridemia, cholesterolemia, and higher serum IL-1β associated with impaired learning and memory. These obese mice also showed activation of microglia and astrocytes and significant immunoreactivity of neuroinflammatory and apoptosis markers, such as TNF-α, COX-2, and Caspase-3, in addition to lower expression of neurogenesis and synaptic plasticity markers, such as NeuN, KI-67, CREB-p, and BDNF. FOS and GOS treatment significantly improved the biochemistry profile and decreased serum IL-1β levels. Treatment with FOS and GOS also reduced TNF-α, COX-2, Caspase-3, Iba-1, and GFAP-positive cells in the dentate gyrus, decreasing neuroinflammation and neuronal death caused by chronic HFD consumption. In addition, FOS and GOS promoted synaptic plasticity by increasing NeuN, p-CREB, BDNF, and KI-67, restoring spatial learning ability and memory. Moreover, FOS and GOS on HFD modulated the insulin pathway, which was proved by up-regulating IRS/PI3K/AKT signaling pathway, followed by a decreasing Aβ plate and Tau phosphorylation. Furthermore, the prebiotic intervention reshaped the HFD-induced imbalanced gut microbiota by modulating the composition of the bacterial community, markedly increasing Bacteroidetes. In addition, prebiotics decreased intestinal inflammation and leaky gut. In conclusion, FOS and GOS significantly modulated the gut microbiota and IRS/PI3K/AKT signaling pathway, decreased neuroinflammation, and promoted neuroplasticity improving spatial learning and memory. Schematic summarizing of the pathways by FOS and GOS improves memory and learning through the gut-brain axis. FOS and GOS improve the microbial profile, reducing intestinal inflammation and leaky gut in the distal colon. Specifically, the administration of FOS and GOS decreases the expression of TLR4, TNF-α, IL-1β, and MMP9 and increases the expression of occludin and IL-10. Prebiotics inhibit neuroinflammation, neuronal apoptosis, and reactive gliosis in the hippocampus but restore synaptic plasticity, neuronal proliferation, and neurogenesis.

Berberine improves inhibitory avoidance memory impairment of Toxoplasma gondii-infected rat model of ketamine-induced schizophrenia

BACKGROUND

Memory impairment caused by Toxoplasma gondii infection has been documented. Berberine (BRB) is well known for its enhancing effects on memory and has shown promising results. However, the impact of BRB on T. gondii infection and schizophrenia-induced consolidation and reconsolidation memory impairment is still unclear. Here; we examined the effect of BRB on the inhibitory avoidance (IA) memory consolidation and reconsolidation impairment induced by T. gondii infection, and ketamine (Ket) as a pharmacological model of schizophrenia. Also; the brain-derived neurotrophic factor (BDNF) levels in the medial prefrontal cortex (mPFC) and hippocampus were analyzed.

METHODS

Rats were infected with T. gondii RH strain or received Ket (30 mg/kg/day) intraperitoneally (i.p) for at least five consecutive days (as the model of schizophrenia). Then followed by oral administration with BRB (25 mg/kg/day) for five days. Finally, the IA memory retention test was examined 48 post-conditioning, and BDNF was measured.

RESULTS

Results indicated IA memory impairment in T. gondii-infected animals since lower step-through latency (STL) was observed than in control animals. We found significant (P = 0.01, P = 0.001) elevations in STL and a significant decrease (P = 0.001) in total time spent in the dark area following BRB administration in infected and Ket-treated rats, indicating improvement (increased STL) in consolidation and reconsolidation memory. Moreover, BDNF levels were reduced (P = 0.01) in the hippocampus and mPFC regions of both T. gondii- infected and Ket-induced groups, which remarkably enhanced after BRB treatment. Furthermore; we found that BRB administration notably increased the mPFC BDNF levels in mPFC (P < 0.01) and hippocampus (P = 0.001) in the Ket-treated and rats infected with T. gondii.

CONCLUSION

Taken together; BRB may be a valuable preclinical treatment for improving memory impairment through BDNF expression in PFC and hippocampus, therefore; BRB is suggested for memory disturbances induced by T. gondii infection.

Alpha-pinene moderates memory impairment induced by kainic acid via improving the BDNF/TrkB/CREB signaling pathway in rat hippocampus

Introduction

The potential benefits of natural ingredients in the alleviation of neurodegenerative disorders are of great interest. Alpha-pinene (APN) is an essential oil belonging to monoterpenes with multiple beneficial effects. In this study, the possible improving effects of alpha-pinene on memory impairment induced by kainic acid and the underlying molecular mechanisms were examined.

Methods

Memory impairment was induced by i.c.v. injection of kainic acid (KA) in male Wistar rats. Alpha-pinene (50 mg/kg/day, i.p.) was injected for 21 days, including 14 days before the KA injection and seven days afterward. Spatial working memory and inhibitory avoidance (IA) memory performance were assessed five and even days following KA injection, respectively. The hippocampal protein levels of brain-derived neurotrophic factor (BDNF), tropomyosin-like receptor kinase B (TrkB), cAMP response element binding protein (CREB), and neuronal loss in the CA1 region were also examined.

Results

Results revealed that the i.c.v. injection of KA triggered memory impairment, which was notably diminished by alpha-pinene pre-and post-treatment. Histopathological evaluation revealed that alpha-pinene significantly moderated the attenuation in CA1 alive neurons induced by KA injection. Western blotting analysis confirmed that alpha-pinene pre-and post-treatment significantly reversed the KA-induced decreases in the hippocampal levels of BDNF, TrkB, phosphorylated TrkB, CREB, and phosphorylated CREB.

Discussion

These findings suggest that alpha-pinene pre-and post-treatment moderate memory impairment induced by KA by restoring the BDNF/TrkB/CREB signaling pathway in the rat hippocampus.

Effect of l-Dopa in acute temozolomide-induced cognitive impairment in male mice: a possible antineuroinflammatory role

Temozolomide is used commonly in the treatment of some types of cancers, but it may also result in cognitive impairments such as memory deficits. l-Dopa, a well known medicine for the central nervous system, has been shown to have positive effects on some cognitive disorders. Here we sought to investigate the effect of l-Dopa on temozolomide-induced cognitive impairments. BALB/c mice were subjected to 3-days temozolomide and 6-days concomitant l-Dopa/benserazide administration in six groups (control, l-Dopa 25 mg/kg, l-Dopa 75 mg/kg, temozolomide, temozolomide + l-Dopa 25 mg/kg, and temozolomide + l-Dopa 75 mg/kg). Open field test, object location recognition, novel object recognition test, and shuttle-box test were carried out to determine the locomotor, anxiety-like behavior, and memory function of subjects. TNF-α and brain-derived neurotrophic factor (BDNF) gene expression in the hippocampus was measured by real-time PCR. Mice treated with temozolomide showed recognition memory impairment, along with hippocampal TNF-α and BDNF mRNA expression level raise, and detection of histological insults in hematoxylin and eosin hippocampal slides. Mice that received temozolomide + l-Dopa showed normal behavioral function and lower TNF-α and BDNF hippocampal mRNA expression levels, and histologically normal hippocampal CA1 region in comparison with mice in the temozolomide group. Our results provide evidence that l-Dopa prevents temozolomide-induced recognition memory deficit in mice at the acute phase probably via l-Dopa antineuroinflammatory effects.

Importance of Magnesium Status in COVID-19

A large amount of published research points to the interesting concept (hypothesis) that magnesium (Mg) status may have relevance for the outcome of COVID-19 and that Mg could be protective during the COVID disease course. As an essential element, Mg plays basic biochemical, cellular, and physiological roles required for cardiovascular, immunological, respiratory, and neurological functions. Both low serum and dietary Mg have been associated with the severity of COVID-19 outcomes, including mortality; both are also associated with COVID-19 risk factors such as older age, obesity, type 2 diabetes, kidney disease, cardiovascular disease, hypertension, and asthma. In addition, populations with high rates of COVID-19 mortality and hospitalization tend to consume diets high in modern processed foods, which are generally low in Mg. In this review, we review the research to describe and consider the possible impact of Mg and Mg status on COVID-19 showing that (1) serum Mg between 2.19 and 2.26 mg/dL and dietary Mg intakes > 329 mg/day could be protective during the disease course and (2) inhaled Mg may improve oxygenation of hypoxic COVID-19 patients. In spite of such promise, oral Mg for COVID-19 has thus far been studied only in combination with other nutrients. Mg deficiency is involved in the occurrence and aggravation of neuropsychiatric complications of COVID-19, including memory loss, cognition, loss of taste and smell, ataxia, confusion, dizziness, and headache. Potential of zinc and/or Mg as useful for increasing drug therapy effectiveness or reducing adverse effect of anti-COVID-19 drugs is reviewed. Oral Mg trials of patients with COVID-19 are warranted.

Bushen-Yizhi formula ameliorates mitochondrial dysfunction and oxidative stress via AMPK/Sirt1 signaling pathway in D-gal-induced aging rats

BACKGROUND

As a major risk factor for neurodegenerative diseases, aging has become a heavy health care burden worldwide. Age-related decline in mitochondrial function and oxidative stress is strongly associated with neurodegeneration. The previous study demonstrated that Bushen-Yizhi formula (BSYZ), a traditional Chinese medicine formula, is effective in reducing neurodegeneration.

METHODS

This study is the first to investigate the effect of BSYZ on D-gal-induced learning memory in rats. Secondly, the potential metabolic mechanism of BSYZ was explored by ¹H-NMR metabolomics analysis. Then based on the comparison of differential metabolites implied that BSYZ ameliorated mitochondrial dysfunction through choline metabolic pathway in D-gal-treated rats. Finally, pharmacological validation was conducted to explore the effects of BSYZ on D-gal-induced oxidative stress, neuroinflammation, and neuronal apoptosis.

RESULTS

Our data showed that BSYZ increased aspartate and betaine levels, while decreasing choline levels. Furthermore, BSYZ also increased the proteins level of CHDH and BHMT to regulate choline metabolic pathway. Meanwhile, BSYZ alleviated mitochondrial damage and oxidative stress, including enhanced ATP production and the ratio of NAD⁺/NADH, reduced the level of MDA, enhanced GSH and SOD activity, upregulated the expressions of p-AMPK, SIRT1 proteins. In addition, BSYZ downregulated the levels of inflammatory cytokines, such as TNF-α, IL-1β and IL-6, as well as suppressed Bcl-2 proteins family dependent apoptosis.

CONCLUSION

BSYZ treatment effectively rescues neurobehavioral impairment by improving mitochondrial dysfunction, oxidative stress, neuroinflammation and neuroapoptosis via AMPK/SIRT1 pathway in D-gal-induced aging.

Cordycepin buffers anisomycin-induced fear memory deficit by restoring hippocampal BDNF

The process of memory consolidation involves the synthesis of new proteins, and interfering with protein synthesis through anisomycin can impair memory. Memory deficits due to aging and sleep disorders may also result from a reduction in protein synthesis. Rescuing memory deficits caused by protein synthesis deficiency is therefore an important issue that needs to be addressed. Our study focused on the effects of cordycepin on fear memory deficits induced by anisomycin using contextual fear conditioning. We observed that cordycepin was able to attenuate these deficits and restore BDNF levels in the hippocampus. The behavioral effects of cordycepin were dependent on the BDNF/TrkB pathway, as demonstrated by the use of ANA-12. Cordycepin had no significant impact on locomotor activity, anxiety or fear memory. Our findings provide the first evidence that cordycepin can prevent anisomycin-induced memory deficits by regulating BDNF expression in the hippocampus.

Neuroprotective effects of PRG on Aβ25-35-induced cytotoxicity through activation of the ERK1/2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Phylloporia ribis (Schumach:Fr.)Ryvarden is a genus of needle Phellinus medicinal fungi, parasitic on the living rhizomes of hawthorn and pear trees. As a traditional Chinese medicine, Phylloporia ribis was used in folklore for long-term illness, weakness and memory loss in old age. Previous studies have shown that polysaccharides from Phylloporia ribis (PRG) significantly promoted synaptic growth in PC12 cells in a dose-dependent manner, exhibiting "NGF"-like neurotrophic activity. Aβ_25-35 damage to PC12 cells produced neurotoxicity and decreased cell survival, and PRG reduced the apoptosis rate, suggesting that PRG has neuroprotective effects. The studies confirmed that PRG had the potential to be a neuroprotective agent, but its neuroprotective mechanism remained unclear.

AIM OF THE STUDY

We aimed to elucidate the neuroprotective effects of PRG in an Aβ_25-35-induced Alzheimer's disease (AD) model.

MATERIALS AND METHODS

Highly-differentiated PC12 cells were treated with Aβ_25-35 (AD model) and PRG, and were assessed for cellular apoptosis, inflammatory factors, oxidative stress, and kinase phosphorylation.

RESULTS

The results showed that the PRG groups effectively inhibited the neurotoxicity, mainly manifested by inhibiting mitochondrial oxidative stress, attenuating neuroinflammatory responses, and improving mitochondrial energy metabolism, eventually resulting in higher cell survival. The expression of p-ERK, p-CREB and BDNF proteins was increased in the PRG groups compared to the model group, which confirmed that PRG reversed the inhibition of the ERK pathway.

CONCLUSION

We provide evidence for neuroprotection conferred by PRG and its mechanism by inhibiting ERK1/2 hyper-phosphorylation, prevention of mitochondrial stress, and subsequent prevention of apoptosis. The study highlights PRG as a promising candidate with neuroprotective effects, the potential of which can be harnessed for identifying novel therapeutic targets.

Acute intrahippocampal administration of melanin-concentrating hormone impairs memory consolidation and decreases the expression of MCHR-1 and TrkB receptors

Interest in the role of melanin-concentrating hormone (MCH) in memory processes has increased in recent years, with some studies reporting memory-enhancing effects, while others report deleterious effects. Due to these discrepancies, this study seeks to provide new evidence about the role of MCH in memory consolidation and its relation with BDNF/TrkB system. To this end, in the first experiment, increased doses of MCH were acutely administered in both hippocampi to groups of male rats (25, 50, 200, and 500 ng). Microinjections were carried out immediately after finishing the sample trial of two hippocampal-dependent behavioral tasks: the Novel Object Recognition Test (NORT) and the modified Elevated Plus Maze (mEPM) test. Results indicated that a dose of 200 ng of MCH or higher impaired memory consolidation in both tasks. A second experiment was performed in which a dose of 200 ng of MCH was administered alone or co-administered with the MCHR-1 antagonist ATC-0175 at the end of the sample trial in the NORT. Results showed that MCH impaired memory consolidation, while the co-administration with ATC-0175 reverted this detrimental effect. Moreover, MCH induced a significant decrease in hippocampal MCHR-1 and TrkB expression with no modification in the expression of BDNF and NMDA receptor subunits NR1, NR2A, and NR2B. These results suggest that MCH in vivo elicits pro-amnesic effects in the rat hippocampus by decreasing the availability of its receptor and TrkB receptors, thus linking both endogenous systems to memory processes.

Diverse Functions of Multiple Bdnf Transcripts Driven by Distinct Bdnf Promoters

The gene encoding brain-derived neurotrophic factor (Bdnf) consists of nine non-coding exons driven by unique promoters, leading to the expression of nine Bdnf transcripts that play different roles in various brain regions and physiological stages. In this manuscript, we present a comprehensive overview of the molecular regulation and structural characteristics of the multiple Bdnf promoters, along with a summary of the current knowledge on the cellular and physiological functions of the distinct Bdnf transcripts produced by these promoters. Specifically, we summarized the role of Bdnf transcripts in psychiatric disorders, including schizophrenia and anxiety, as well as the cognitive functions associated with specific Bdnf promoters. Moreover, we examine the involvement of different Bdnf promoters in various aspects of metabolism. Finally, we propose future research directions that will enhance our understanding of the complex functions of Bdnf and its diverse promoters.

Effectiveness of a Computerized Home-Based Cognitive Stimulation Program for Treating Cancer-Related Cognitive Impairment

Cancer patients assert that after chemotherapy their cognitive abilities have deteriorated. Cognitive stimulation is the clinical treatment of choice for reversing cognitive decline. The current study describes a computerized home-based cognitive stimulation program in patients who survived breast cancer. It aims to assess safety and effectiveness of cognitive stimulation in the oncology population. A series of 45-min training sessions was completed by the participants. A thorough assessment was performed both before and after the intervention. The mini-Mental Adjustment to Cancer Scale, the Cognitive Assessment for Chemo Fog Research, and the Functionality Assessment Instrument in Cancer Treatment-Cognitive Function served as the main assessment tools. The State-Trait Anxiety Inventory, Beck Depression Inventory, Brief Fatigue Inventory, and Measuring Quality of Life-The World Health Organization data were gathered as secondary outcomes. Home-based cognitive stimulation demonstrated beneficial effects in the oncology population, with no side effects being reported. Cognitive, physical, and emotional improvements were observed, along with decreased interference in daily life activities and a better overall quality of life.

The NMDA receptor antagonists memantine and ketamine as anti-migraine agents

Migraine is a debilitating disorder affecting females more frequently than males. There is some evidence that drugs targeting glutamate receptors: memantine and ketamine might be beneficial in the therapy of this entity. Therefore, the purpose of this work is to present NMDA receptor antagonists, memantine and ketamine, as potential anti-migraine agents. We searched PubMed/MEDLINE, Embase, and clinical trials submitted to ClinicalTrials.gov to find publications describing eligible trials published between database inception and December 31, 2021. This comprehensive literature review summarizes data on the use of the NMDA receptor antagonists memantine and ketamine in the pharmacotherapy of migraine. Results from 20 previous and recent preclinical experiments are discussed and correlated with 19 clinical trials (including case series, open-label, and randomized placebo-controlled trials). For the purposes of this review, the authors hypothesized that the propagation of SD is a major mechanism in the pathophysiology of migraine. In several animal studies and in vitro studies, memantine and ketamine inhibited or reduced propagation of the SD. In addition, the results of clinical trials suggest that memantine or ketamine may be an effective treatment option for migraine. However, most studies on these agents lack control group. Although further clinical trials are needed, the results suggest that ketamine or memantine may be promising molecules for the treatment of severe migraine. Particular attention should be paid to people who have a treatment-resistant form of migraine with aura or have exhausted existing treatment options. For them, the drugs under discussion could represent an interesting alternative in the future.

Longitudinal Changes in BDNF and MMP-9 Protein Plasma Levels in Children after Cochlear Implantation

Congenitally deaf children who undergo cochlear implantation before 1 year of age develop their auditory skills faster than children who are implanted later. In this longitudinal study, a cohort of 59 implanted children were divided into two subgroups according to their ages at implantation-below or above 1 year old-and the plasma levels of matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and pro-BDNF were measured at 0, 8, and 18 months after cochlear implant activation, while auditory development was simultaneously evaluated using the LittlEARs Questionnaire (LEAQ). A control group consisted of 49 age-matched healthy children. We identified statistically higher BDNF levels at 0 months and at the 18-month follow-ups in the younger subgroup compared to the older one and lower LEAQ scores at 0 months in the younger subgroup. Between the subgroups, there were significant differences in the changes in BDNF levels from 0 to 8 months and in LEAQ scores from 0 to 18 months. The MMP-9 levels significantly decreased from 0 to 18 months and from 0 to 8 months in both subgroups and from 8 to 18 months only in the older one. For all measured protein concentrations, significant differences were identified between the older study subgroup and the age-matched control group.

Vitamin B12 administration prevents ethanol-induced learning and memory impairment through re-establishment of the brain oxidant/antioxidant balance, enhancement of BDNF and suppression of GFAP

There are growing evidence indicating that the adolescent brain is persistently affected by the use of psychostimulant agents. In this regard, alcohol drinking has become rather common among the adolescents in many societies during the last decade. It is currently well known that long-term ethanol exposure deteriorates various cognitive functions such as learning and memory. Mechanistically, these adverse effects have been shown to be mediated by oxidative damage to central nervous system. On the other hand, Vit-B12 is known to improve cognitive performance by suppression of oxidative parameters. Thus, in the present study we aimed to test whether treatment by Vit-B12 could prevent ethanol-induced complications in mice using behavioral and biochemical methods. Different groups of male Syrian mice received ethanol, ethanol+Vit-B12, Vit-B12 alone, or saline during adolescence and then learning and memory functions were assessed by Morris water maze (MWM) and Passive Avoidance (PA) tests. Finally, mice were sacrificed for measurement of biochemical factors. Results indicated that, adolescent ethanol intake impairs learning and memory function through exacerbation of oxidative stress and Vit-B12 treatment improves these complications by re-establishment of oxidant/anti-oxidant balance in CNS. Moreover, we found that Vit-B12 prevents ethanol-induced reduction of BDNF and enhancement of GFAP and acetylcholinesterase (AChE) activity. In conclusion, it seems that Vit-B12 supplementation could be used as an effective therapeutic strategy to prevent learning and memory defects induced by chronic alcohol intake during adolescence.

Multisession Anodal Transcranial Direct Current Stimulation Enhances Adult Hippocampal Neurogenesis and Context Discrimination in Mice

Transcranial direct current stimulation (tDCS) is a promising noninvasive neuromodulatory treatment option for multiple neurologic and psychiatric disorders, but its mechanism of action is still poorly understood. Adult hippocampal neurogenesis (AHN) continues throughout life and is crucial for preserving several aspects of hippocampal-dependent cognitive functions. Nevertheless, the contribution of AHN in the neuromodulatory effects of tDCS remains unexplored. Here, we sought to investigate whether multisession anodal tDCS may modulate AHN and its associated cognitive functions. Multisession anodal tDCS were applied on the skull over the hippocampus of adult male mice for 20 min at 0.25 mA once daily for 10 d totally. We found that multisession anodal tDCS enhances AHN by increasing the proliferation, differentiation and survival of neural stem/progenitor cells (NSPCs). In addition, tDCS treatment increased cell cycle reentry and reduced cell cycle exit of NSPCs. The tDCS-treated mice exhibited a reduced GABAergic inhibitory tone in the dentate gyrus compared with sham-treated mice. The effect of tDCS on the proliferation of NSPCs was blocked by pharmacological restoration of GABA_B receptor-mediated inhibition. Functionally, multisession anodal tDCS enhances performance on a contextual fear discrimination task, and this enhancement was prevented by blocking AHN using the DNA alkylating agent temozolomide (TMZ). Our results emphasize an important role for AHN in mediating the beneficial effects of tDCS on cognitive functions that substantially broadens the mechanistic understanding of tDCS beyond its well-described in hippocampal synaptic plasticity.SIGNIFICANCE STATEMENT Transcranial direct current stimulation (tDCS) has been shown to effectively enhance cognitive functions in healthy and pathologic conditions. However, the mechanisms underlying its effects are largely unknown and need to be better understood to enable its optimal clinical use. This study shows that multisession anodal tDCS enhances adult hippocampal neurogenesis (AHN) and therefore contributes to enhance context discrimination in mice. Our results also show that the effect of tDCS on AHN is associated with reduced GABAergic inhibition in the dentate gyrus. Our study uncovers a novel mechanism of anodal tDCS to elicit cognitive-enhancing effects and may have the potential to improve cognitive decline associated with normal aging and neurodegenerative disorders.

Cardiovascular exercise, learning, memory, and cytokines: Results of a ten-week randomized controlled training study in young adults

Physical exercise has been shown to enhance memory and to increase neuroplasticity. Rodent studies have revealed modulating effects of signaling molecules of the immune system (cytokines) on hippocampal plasticity and memory. Acute and chronic exercise have been both found to alter the number and function of immune cells. Thus, physical exercise might enhance neuroplasticity via an altered immune response. In this study we tested whether multiple repetitions of a vocabulary learning task combined with a bout of cardiovascular exercise enhances learning in humans and whether memory improvements correlated with acute exercise-induced cytokine changes. Data of 52 participants (20-40 years of age) who were randomly assigned to a cardiovascular exercise group (cycling) or a control group (stretching) were analyzed. During the 10-week treatment, participants completed 18 learning-exercise sessions. In each of these sessions, the vocabulary learning task was always performed immediately before exercising started. To assess acute exercise-induced changes in cytokine levels, blood sampling was performed at rest and immediately after exercising in two of the sessions. Learning success measured as increase in learning across all sessions and vocabulary retention four weeks after the treatment had ended did not differ between groups. The cycling group showed a relatively larger acute increase in IL-6, IL-1ra, IL-4, and IFN-γ compared to the stretching group. Exploratory analyses revealed significant positive associations between within-session learning and acute exercise-induced increases in IL-6 and IL-1ra in the cycling group only. These results suggest that the immune system may act as a mediator of exercise-induced cognitive benefits.

Combined oral contraceptives and mental health: Are adolescence and the gut-brain axis the missing links?

Combined oral contraceptives (containing synthetic forms of estradiol and progestins) are one of the most commonly used drugs among females. However, their effects on the gut-brain axis have not been investigated to a great extent despite clear evidence that suggest bi-directional interactions between the gut microbiome and endogenous sex hormones. Moreover, oral contraceptives are prescribed during adolescence, a critical period of development during which several brain structures and systems, such as hypothalamic-pituitary-gonadal axis, undergo maturation. Considering that oral contraceptives could impact the developing adolescent brain and that these effects may be mediated by the gut-brain axis, further research investigating the effects of oral contraceptives on the gut-brain axis is imperative. This article briefly reviews evidence from animal and human studies on the effects of combined oral contraceptives on the brain and the gut microbiota particularly during adolescence.

Endocytosis is required for consolidation of pattern-separated memories in the perirhinal cortex

Introduction

The ability to separate similar experiences into differentiated representations is proposed to be based on a computational process called pattern separation, and it is one of the key characteristics of episodic memory. Although pattern separation has been mainly studied in the dentate gyrus of the hippocampus, this cognitive function if thought to take place also in other regions of the brain. The perirhinal cortex is important for the acquisition and storage of object memories, and in particular for object memory differentiation. The present study was devoted to investigating the importance of the cellular mechanism of endocytosis for object memory differentiation in the perirhinal cortex and its association with brain-derived neurotrophic factor, which was previously shown to be critical for the pattern separation mechanism in this structure.

Methods

We used a modified version of the object recognition memory task and intracerebral delivery of a peptide (Tat-P4) into the perirhinal cortex to block endocytosis.

Results

We found that endocytosis is necessary for pattern separation in the perirhinal cortex. We also provide evidence from a molecular disconnection experiment that BDNF and endocytosis-related mechanisms interact for memory discrimination in both male and female rats.

Discussion

Our experiments suggest that BDNF and endocytosis are essential for consolidation of separate object memories and a part of a time-restricted, protein synthesis-dependent mechanism of memory stabilization in Prh during storage of object representations.

Synapse-specific changes in Arc and BDNF in rat hippocampus following chronic temporal lobe epilepsy

Expression of immediate early genes (IEGs) in the brain is important for synaptic plasticity, and probably also in neurodegenerative conditions. To understand the cellular mechanisms of the underlying neuropathophysiological processes in epilepsy, we need to pinpoint changes in concentration of synaptic plasticity-related proteins at subsynaptic levels. In this study, we examined changes in synaptic expression of Activity-regulated cytoskeleton-associated (Arc) and Brai Derived Neurotrophic Factor (BDNF) in a rat model of kainate-induced temporal lobe epilepsy (TLE). Western blotting showed reduced concentrations of Arc and increased concentrations of BDNF in hippocampal synaptosomes in chronic TLE rats. Then, using quantitative electron microscopy, we found corresponding changes in subsynaptic regions in the hippocampus. Specifically, we detected significant reductions in the concentrations of Arc in the presynaptic terminal of Schaffer collateral glutamatergic synapses in the stratum radiatum of the CA1 area in TLE, as well as in their adjacent postsynaptic spines. In CA3, there was a significant reduction of Arc only in the presynaptic terminal cytoplasm. Conversely, in CA3, there was a significant increase in the expression of BDNF in the presynaptic terminal, but not in the postsynaptic spine. Significant increase in BDNF concentration in the CA1 postsynaptic density was also obtained. We hypothesize that the observed changes in Arc and BDNF may contribute to both cognitive impairment and increased excitotoxic vulnerability in chronic epilepsy.

Aluminum Oxide Nanoparticles Impair Working Memory and Neuronal Activity through the GSK3β/BDNF Signaling Pathway of Prefrontal Cortex in Rats

Studies demonstrated that alumina nanoparticles (alumina NPs) impair spatial cognition and hippocampus-dependent synaptic plasticity. Although alumina NPs accumulate in the prefrontal cortex (PFC), their effects on PFC-mediated neuronal and cognitive function have been not yet documented. Here, alumina NPs (10 or 20 μg/kg of body weight) were bilaterally injected into the medial PFC (mPFC) of adult rats, and the levels of glycogen synthase kinase 3β (GSK3β) and the brain-derived neurotrophic factor (BDNF) were detected. The PFC-dependent working memory task with one-minute or three-minute delay time was conducted. Meanwhile, the neuronal correlates of working memory performance were recorded. The specific expression of neuronal BDNF was assessed by colabeled BDNF expression with the neuronal nuclear antigen (NeuN). Whole-cell patch-clamp recordings were employed to detect neuronal excitability. Intra-mPFC alumina NP infusions significantly enhanced the expression of GSK3β but reduced the phosphorylation of GSK3β (pGSK3β) and BDNF levels more severely at a dose of 20 μg/kg. Alumina NPs acted in a dose-dependent manner to impair working memory. The neuronal expression of BDNF in the 20 μg/kg group was markedly declined compared with the 10 μg/kg group. During the delay time, the neuronal frequency of pyramidal cells but not interneurons was significantly weakened. Furthermore, both the frequency and amplitude of the excitatory postsynaptic currents (EPSCs) were descended in the mPFC slices. Additionally, the infusion of GSK3β inhibitor SB216763 or BDNF could effectively attenuate the impairments in neuronal correlate, neuronal activity, and working memory. From the perspective of the identified GSK3β/BDNF pathway, these findings demonstrated for the first time that alumina NPs exposure can be a risk factor for prefrontal neuronal and cognitive functions.

Effects of hemp seed alone and combined with aerobic exercise on metabolic parameters, oxidative stress, and neurotrophic factors in young sedentary men

Hemp seed and physical activity (PA) have many benefits for the metabolic and brain health of the body. This study investigated the effects of hemp seed alone and aerobic exercise on metabolic markers, oxidative stress, and neurotrophic factors in young sedentary men. This double-blind, placebo-controlled, randomized clinical trial was conducted on 48 sedentary young men in Tabriz, Iran, from April to August. The researcher in this study randomized all participants into four groups, including (1) hemp seed, (2) hemp seed + PA, (3) PA + placebo, and (4) placebo. Hemp seed supplement was administered in two 1-g capsules daily, and aerobic PA was performed a week thrice. Levels of anthropometric indices, dietary intake, antioxidant markers, lipid profile, fasting blood sugar (FBS), insulin, homeostatic model assessment for insulin resistance (HOMA-IR), quantitative insulin-sensitivity check index (QUICKI), brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), balance, reaction time, and sit-ups were evaluated for all participants at baseline and post-intervention. We used ANOVA and ANCOVA analysis to compare oxidative stress and neurotropic factors in all intervention groups. If the distribution of the response variable was not normal, the non-parametric equivalent of these tests was used (Wilcoxon and Kruskal-Wallis tests). We performed all statistical analyzes using SPSS software version 23, and the significance level was considered 0.05 in all the statistical tests. Aerobic PA with hemp seed consumption caused a significant difference in weight, body mass index, fat mass, high-density lipoprotein, catalase, and BDNF compared with baseline. Also, aerobic PA alone caused significant changes in body weight, fat mass, and triglyceride compared with baseline. Consumption of hemp seeds alone caused a significant increase in high-density lipoprotein levels compared with baseline. At the end of the study, fat mass, total cholesterol, low-density lipoproteins, and BDNF were significantly different between the groups. According to our results, aerobic PA combined with hemp seed consumption may improve anthropometric indices, lipid profile, and BDNF and improve health outcomes like cardiovascular comorbidities, oxidative stress, and insulin resistance. PRACTICAL APPLICATIONS: A sedentary lifestyle has numerous health-threatening consequences like cardiovascular comorbidities, oxidative stress, and insulin resistance. The importance of physical activity (PA) in improving these clinical manifestations is well-known; however, the potential benefits of herbal therapy combined with PA in reducing the side effects of a sedentary lifestyle have not been well studied. In the current research, we evaluated the benefits of hemp seed alone and combined with aerobic exercise on metabolic markers, oxidative stress, and neurotrophic factors in young sedentary men for the first time. According to our results, aerobic PA combined with hemp seed consumption improved anthropometric indices, lipid profile, and brain-derived neurotrophic factor among young sedentary men.

Hippocampus-prefrontal cortex inputs modulate spatial learning and memory in a mouse model of sepsis induced by cecal ligation puncture

AIMS

Sepsis-associated encephalopathy (SAE) often leads to cognitive impairments. However, the pathophysiology of SAE is complex and unclear. Here, we investigated the role of hippocampus (HPC)-prefrontal cortex (PFC) in cognitive dysfunction in sepsis induced by cecal ligation puncture (CLP) in mice.

METHODS

The neural projections from the HPC to PFC were first identified via retrograde tracing and viral expression. Chemogenetic activation of the HPC-PFC pathway was shown via immunofluorescent staining of c-Fos-positive neurons in PFC. Morris Water Maze (MWM) and Barnes maze (BM) were used to evaluate cognitive function. Western blotting analysis was used to determine the expression of glutamate receptors and related molecules in PFC and HPC.

RESULTS

Chemogenetic activation of the HPC-PFC pathway enhanced cognitive dysfunction in CLP-induced septic mice. Glutamate receptors mediated the effects of HPC-PFC pathway activation in CLP mice. The activation of the HPC-PFC pathway resulted in significantly increased levels of NMDAR, AMPAR, and downstream signaling molecules including CaMKIIa, pCREB, and BDNF in PFC. However, inhibition of glutamate receptors using 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo (F)quinoxaline (NBQX), which is an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR inhibitor), or D-2-amino-5-phosphonopentanoate (D-AP5), which is an NMDA receptor antagonist abolished this increase.

CONCLUSION

Our study reveals the important role of the HPC-PFC pathway in improving cognitive dysfunction in a mouse model of CLP sepsis and provides a novel pathogenetic mechanism for SAE.

BDNF and its Role in the Alcohol Abuse Initiated During Early Adolescence: Evidence from Preclinical and Clinical Studies

Brain-derived neurotrophic factor (BDNF) is a crucial brain signaling protein that is integral to many signaling pathways. This neurotrophin has shown to be highly involved in brain plastic processes such as neurogenesis, synaptic plasticity, axonal growth, and neurotransmission, among others. In the first part of this review, we revise the role of BDNF in different neuroplastic processes within the central nervous system. On the other hand, its deficiency in key neural circuits is associated with the development of psychiatric disorders, including alcohol abuse disorder. Many people begin to drink alcohol during adolescence, and it seems that changes in BDNF are evident after the adolescent regularly consumes alcohol. Therefore, the second part of this manuscript addresses the involvement of BDNF during adolescent brain maturation and how this process can be negatively affected by alcohol abuse. Finally, we propose different BNDF enhancers, both behavioral and pharmacological, which should be considered in the treatment of problematic alcohol consumption initiated during the adolescence.

Yuk-Gunja-Tang attenuates neuronal death and memory impairment via ERK/CREB/BDNF signaling in the hippocampi of experimental Alzheimer’s disease model

Yuk-Gunja-Tang (YG) is the Korean traditional medicine in East Asia for gastrointestinal disorders. In the present study, we determined the protective effects of YG on glutamate-induced cytotoxicity in HT22 hippocampal neuronal cells and mice with scopolamine-induced memory impairment. In vitro assessments were performed using a cell viability assay, flow cytometry, and Western blotting, while in vivo assessments were performed in C57BL/6 mice administered with YG for 7 days and injected with scopolamine (1 mg/kg) for 7 days. We assessed the memory function using the Y-maze, novel object recognition, and passive avoidance tests. Protein expression analyses and histological analyses were performed using hippocampal tissues. YG treatment significantly restored cell viability against glutamate-induced apoptosis. It significantly suppressed glutamate-induced reactive oxygen species accumulation and mitochondrial dysfunction. It also increased Bcl-2 protein expression and decreased HO-1 protein expression. It activated the extracellular signal-regulated kinase/cAMP response element binding protein (ERK/CREB) signaling pathway and increased the expression of brain-derived neurotrophic factor (BDNF) under excitotoxic conditions. In the scopolamine-injected mice, YG ameliorated memory impairment in the Y-maze, novel object recognition, and passive avoidance tests; restored dysfunction in the acetylcholine, acetylcholinesterase expression levels; reduced neuronal damage in Nissl staining; and increased BDNF and phosphorylated ERK and CREB levels in Western blotting and immunofluorescence staining. Thus, YG exerted neuroprotective effects by activating ERK/CREB/BDNF signaling in the hippocampus, indicating its potential cognition-enhancing effects, especially in Alzheimer’s disease.

Memory Modulation by Exercise in Young Adults Is Related to Lactate and Not Affected by Sex or BDNF Polymorphism

Currently, high-intensity interval exercise (HIIE) is on the rise compared to moderate-intensity exercise (MIE) due to its similar benefits for health and performance with low time requirements. Recent studies show how physical exercise can also influence cognitive function, although the optimal dose and underlying mechanisms remain unknown. Therefore, in our study, we have compared the effects on visuospatial and declarative memory of different exercise intensities (HIIE vs. MIE), including possible implicated factors such as lactate released after each session and the Brain-Derived Neurotrophic Factor (BDNF) genotype. Thirty-six undergraduate students participated in this study. The HIIE session consisted of a 3 min warm-up, four 2 min sets at 90−95% of the maximal aerobic speed (MAS) with 2 min of passive recovery between sets, and a 3 min cooldown, and the MIE session implies the same total duration of continuous exercise at 60% of the MAS. Better improvements were found after HIIE than MIE on the backward condition of the visuospatial memory test (p = 0.014, ηp2 = 0.17) and the 48 h retention of the declarative memory test (p = 0.04; d = 0.34). No differences were observed in the forward condition of the visuospatial memory test and the 7-day retention of the declarative memory test (p > 0.05). Moreover, non-modifiable parameters such as biological sex and BDNF polymorphism (Val/Val, Val/Met, or Met/Met) did not modulate the cognitive response to exercise. Curiously, the correlational analysis showed associations (p < 0.05) between changes in memory (visuospatial and declarative) and lactate release. In this sense, our results suggest an important role for intensity in improving cognitive function with exercise, regardless of genetic factors such as biological sex or BDNF Val66Met polymorphism.