Brain-derived neurotrophic factor in the control human brain, and in Alzheimer's disease and Parkinson's disease

Selenium ameliorates cognitive impairment through activating BDNF/TrkB pathway

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder that primarily affects older adults. Selenium, an essential micronutrient for humans, plays a crucial role in the body's normal physiological and metabolic processes. A long-term deficiency in selenium intake can lead to various diseases and even contribute to the ageing process. This study aims to explore the ameliorative effect of selenium on cognitive impairment in 3 × Tg-AD mice and to determine if its effects are related to the BDNF/TrkB pathway.

METHODS

We employed the APP/PS1/tau 3 × Tg-AD mouse model for dietary selenium intervention. Behavioural experiments were conducted to assess learning and memory. Additionally, we measured selenium and GSH-Px levels in whole blood and brain tissue. Neuronal apoptosis in the hippocampus was observed using transmission electron microscopy. The expressions of Aβ, P-tau, BDNF, TrkB, and CREB were measured via RT-qPCR, while the expressions of Aβ, P-tau, BDNF, TrkB, p-CREB, and CREB were quantified using Western blot analysis.

RESULTS

Our findings indicate that selenium supplementation can improve spatial learning and memory deficiencies in 3 × Tg-AD mice. Selenium supplementation increased selenium and GSH-Px levels in the brain tissue of 3 × Tg-AD mice and significantly enhanced neuronal conditions. Furthermore, the expression levels of proteins related to the BDNF/TrkB pathway significantly increased following selenium supplementation.

CONCLUSIONS

Our study demonstrates that selenium can ameliorate memory impairment in 3 × Tg-AD mice by activating the BDNF/TrkB pathway.

Effects of TGF-β1 on Aβ-40 and α- β- γ secretase expression in hippocampus and prefrontal cortex in experimental Alzheimer's disease

Alzheimer's disease is a chronic complex neurodegenerative disease characterized with amyloid plaques and loss of neurons. TGF-β1 is important growth factor, plays critical roles in cell metabolism, tissue homeostasis, neuronal development, and synaptic plasticity. In this study, we aimed to examine the effect of TGF-β1 on the regulation of α, β, and γ-secretase enzymes, Aβ-40 accumulation, apoptosis, and neuronal damage in an experimental Scopolamine-induced AD-like model. The subjects were divided into 5 groups such as control, sham, TGF-β1 control, Scopolamin group, TGF-β1 treatment groups.Then all groups were divided into 2 subgroups according to 28th-56th days. Except for Morris water maze (MWM) test, hippocampus and prefrontal cortex tissues were taken for light-electron microscopic, immunohistochemical, and biochemical examinations. It was observed that learning and memory abilities, which decreased in the MWM test of the Scopolamine group, increased in the treatment groups. In addition, α-secretase expression decreased in the Scopolamin group, while it increased in the TGF-β1 treatment group. It was determined that Aβ-40 and caspase-3 immunoreactivity, β and γ-secretase enzyme levels increased in the Scopolamin group and decreased in TGF-β1 treatment group. Cellular degenerations were relatively decreased in TGF-β1 treatment group. It was thought that TGF-β1 might have a therapeutic effect on Alzheimer's disease by increasing memory performance and preventing Aβ-40 accumulation in the AD-like model induced by Scopolamine and also, may be effective preventing neuronal damage by down-regulating caspase-3 expression. When all the findings evaluated together, it was concluded that TGF-β1 could be evaluated as a therapeutic agent in Alzheimer's disease.

α-Bisabolol alleviates doxorubicin-induced cognitive dysfunction in rats via enhancing the hippocampal BDNF/TrKB signaling and inhibiting neuroinflammation

Chemofog is a serious sequela commonly manifested among cancer patients receiving doxorubicin (DOX) chemotherapy. Our goal was to explore the abrogative action of α-Bisabolol (BISA), a phytochemical sesquiterpene, against DOX-induced cognitive deficit. Rats were allocated into 5 groups: Group I: control; Group II received BISA orally (100 mg/kg/day for 4 weeks); Group III received DOX (2 mg/kg/week/i.p.) for 4 weeks; Groups IV and V were administered BISA orally at 50 and 100 mg/kg, respectively plus DOX, i. p. Results: 1) BISA attenuated DOX-induced chemofog as shown in memory-related behavioral tests. 2) BISA restored the hippocampal histological structure and redox homeostasis via diminishing MDA content and upregulating Nrf2 and HO-1 genes. 3) BISA mitigated DOX-induced neuroinflammation through reducing NF-kB, TNF-α, IL-6, IL-1β, and GFAP expressions. 4) BISA repressed the hippocampal apoptosis via downregulating Bax gene and upregulating Bcl-2 gene. 5) BISA enhanced the synaptic plasticity by activating the BDNF/TrKB signaling and increasing the levels of neurotransmitters that enhance memory, i.e., ACh, 5-HT, and DA. BISA at 100 mg/kg/day exerted a better neuroprotection than BISA at 50 mg/kg/day. Thus, BISA may protect cancer patients from cognitive disorders caused by DOX.

Third-Generation Antipsychotics: The Quest for the Key to Neurotrophism

Antipsychotic drugs (APs) have profoundly changed the treatment landscape for psychiatric disorders, yet their impact on neuroplasticity and neurotrophism remains only partially understood. While second-generation antipsychotics (SGAs) are associated with a better side effect profile than their predecessors, the emergence of third-generation antipsychotics (TGAs)-such as brexpiprazole, cariprazine, lurasidone, iloperidone, lumateperone, pimavanserin, and roluperidone-has prompted renewed interest in their potential neuroprotective and pro-cognitive effects. This review attempts to carefully examine the evidence on the neurotrophic properties of TGAs and their role in modulating brain plasticity by analyzing studies published between 2010 and 2024. Although data remain limited and focused primarily on earlier SGAs, emerging findings suggest that some TGAs may exert positive effects on neuroplastic processes, including the modulation of brain-derived neurotrophic factors (BDNFs) and synaptic architecture. However, robust clinical data on their long-term effects and comparative efficacy are lacking; therefore, further research is necessary to validate their role in preventing neurodegenerative changes and improving cognitive outcomes in patients with psychiatric conditions.

Amelioration of Astrocytic Dysfunction via AQP4/LRP1 Pathway by Zizania latifolia and Tricin in C6 Cells Exposed to Amyloid β and High-Dose Insulin and in Mice Treated with Scopolamine

Zizania latifolia and its bioactive compound tricin have been recognized for their anti-inflammatory, anti-allergic, and anti-aging properties. However, the impact of Z. latifolia extract (ZLE) and tricin on astrocyte dysfunction, particularly related to disruptions in the amyloid β (Aβ) clearance pathway, has not been extensively studied. This research aims to explore the regulatory effects of ZLE and tricin on astroglial dysfunction, utilizing astrocytic differentiated C6 cells (passages 75~85) subjected to Aβ and high-dose insulin, as well as scopolamine-induced mice. Results revealed that ZLE (500 μg/ml) and tricin (1 μg/ml) significantly upregulated the expression of astrocyte proteins GFAP and AQP4, brain-derived neurotrophic factor (BDNF), low-density lipoprotein receptor-related protein 1 (LRP1), and matrix metalloproteinases (MMPs) in C6 cells treated with Aβ and high-dose insulin. Furthermore, oral administration of ZLE (100 and 300 mg/kg) and tricin (0.3 mg/kg) in mice led to an increase in acetylcholine (ACh) levels and upregulation of insulin-degrading enzyme (IDE), LRP1, and MMPs, while reducing the levels of acetylcholinesterase (AChE), Aβ and ApoE4. These findings suggest that ZLE and tricin may ameliorate Aβ and high-dose insulin-induced astrocyte dysfunction in C6 cells and scopolamine-treated mice, potentially through the AQP4/LRP1 pathway.

Gray and white matter differences in the medial temporal lobe in late-life depression: a multimodal PET-MRI investigation

BACKGROUND

Late-life depression (LLD) is characterized by medial temporal lobe (MTL) abnormalities. Although gray matter (GM) and white matter (WM) differences in LLD have been reported, few studies have investigated them concurrently. Moreover, the impact of aetiological factors, such as neurodegenerative and cerebrovascular burden, on tissue differences remains elusive.

METHODS

This prospective cross-sectional study involved 72 participants, including 33 patients with LLD (mean age 72.2 years, 23 female) and 39 healthy controls (HCs) (mean age 70.6 years, 24 female), who underwent clinical and positron emission tomography (PET)-magnetic resonance imaging (MRI) assessments. High-resolution 3D T1-weighted and T2-weighted FLAIR images were used to assess MTL GM volumes and white matter hyperintensities (WMHs), a proxy for cerebrovascular burden. Diffusion kurtosis imaging metrics derived from multishell diffusion MRI data were analyzed to assess WM microstructure in the following MTL bundles reconstructed using constrained spherical deconvolution tractography: uncinate fasciculus, fornix, and cingulum. Standardized uptake value ratio of 18F-MK-6240 in the MTL was used to assess Alzheimer's disease (AD) type tau accumulation as a proxy for neurodegenerative burden.

RESULTS

Compared to HCs, patients with LLD showed significantly lower bilateral MTL volumes and WM microstructural differences primarily in the uncinate fasciculi bilaterally and right fornix. In patients with LLD, higher vascular burden, but not tau, was associated with lower MTL volume and more pronounced WM differences.

CONCLUSIONS

LLD was associated with both GM and WM differences in the MTL. Cerebrovascular disease, rather than AD type tau-mediated neurodegenerative processes, may contribute to brain tissue differences in LLD.

Neurotrophomodulatory effect of TNF-α through NF-κB in rat cortical astrocytes

Tumor necrosis factor alpha (TNF-α) is a well-known pro-inflammatory cytokine originally recognized for its ability to induce apoptosis and cell death. However, recent research has revealed that TNF-α also plays a crucial role as a mediator of cell survival, influencing a wide range of cellular functions. The signaling of TNF-α is mediated through two distinct receptors, TNFR1 and TNFR2, which trigger various intracellular pathways, including NF-κB, JNK, and caspase signaling cascades. Both TNFR1 and TNFR2 are expressed in astrocytes, which are specialized glial cells essential for maintaining the structural and functional integrity of the central nervous system (CNS). Astrocytes support neuronal function by regulating brain homeostasis, maintaining synaptic function, and supplying metabolic substrates. In addition, astrocytes are known to secrete a variety of growth factors and neurotrophins, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and NT-4/5. These neurotrophins play a critical role in supporting neuronal survival, synaptic plasticity, and myelination within the brain. The present study focuses on the role of TNF-α in modulating neurotrophin expression and secretion in rat cortical astrocytes. We demonstrate that TNF-α induces the upregulation of neurotrophins, particularly NGF and BDNF, in cultured astrocytes. This effect is accompanied by an increase in the expression of their respective receptors (TrkA & TrkB), further suggesting a functional modulation of neurotrophic signaling pathways. Notably, we show that the modulation of neurotrophin expression by TNF-α is mediated via the NF-κB signaling pathway. Additionally, we observed that TNF-α also regulates the secretion levels of NGF and BDNF into the culture media of astrocytes in a dose-dependent manner, indicating that TNF-α can modulate both the production and release of these growth factors. Taken together, our findings highlight a previously underexplored neuroprotective role of TNF-α in astrocytes. Specifically, we propose that TNF-α, through the upregulation of neurotrophins, may contribute to maintaining neuronal health and supporting neuroprotection under disease conditions.

Borax attenuates oxidative stress, inflammation, and apoptosis by modulating Nrf2/ROS balance in acrylamide-induced neurotoxicity in rainbow trout

Acrylamide (ACR) can have adverse environmental effects because of its multiple applications. Relevant scientific literatures of the existence of ACR residues in foods following processing steps have raised concern in the biochemistry, chemistry and safety of this vinyl substance. The interest has focused on the hepatotoxicity of ACR in animals and humans and on the ACR content mitigation and its detoxification. Borax (BX), as a naturally occurring antioxidant featured boron compound, was selected in this investigation to assess its possible neuro-protective potential against ACR-induced neurotoxicity. Nrf2 axis signaling pathways and detoxification response to oxidative stress after exposure to ACR in brains of rainbow trout, and the effect of BX application on reducing ACR-induced neurotoxicity were investigated. Rainbow trout were acutely exposed to ACR (12.5 mg/L) alone or simultaneously treated with BX (0.75 mg/L) during 96h. The exposed fish were sampled at 48th and 96th and oxidative stress response endpoints, 8-OHdG, Nrf2, TNF-α, caspase-3, in addition to IL-6 activities and the levels of AChE and BDNF in brain tissues of rainbow trout (Oncorhynchus mykiss) were evaluated. Samples showed decreases in the levels of ACR-mediated biomarkers used to assess neural toxicity (SOD, CAT, GPx, AChE, BDNF, GSH), increased levels of MDA, MPO, DNA damage and apoptosis. ACR disrupted the Nrf2 pathway, and induced neurotoxicity. Inhibited activities' expressions under simultaneous administration experiments, revealed the protective effects of BX against ACR-induced toxicity damage. The obtained data allow the outline of early multi-parameter signaling pathways in rainbow trout.

Behavioral and Biochemical Effects of an Arylhydrazone Derivative of 5-Methoxyindole-2-Carboxylic Acid in a Scopolamine-Induced Model of Alzheimer's Type Dementia in Rats

Alzheimer's disease (AD) has long proven to be a complex neurodegenerative disorder, with cholinergic dysfunction, oxidative stress, and neuroinflammation being just a few of its pathological features. The complexity of the disease requires a multitargeted treatment covering its many aspects. In the present investigation, an arylhydrazone derivative of 5-methoxyindole-2-carboxylic acid (5MeO), with in vitro strong antioxidant, neuroprotective and monoamine oxidase B-inhibiting effects, was studied in a scopolamine-induced Alzheimer-type dementia in rats. Using behavioral and biochemical methods, we evaluated the effects of 5MeO on learning and memory, and elucidated the mechanisms of these effects. Our experiments demonstrated that 5MeO had a beneficial effect on different types of memory as assessed by the step-through and the Barnes maze tasks. It efficiently restored the decreased by scopolamine brain-derived neurotrophic factor and acetylcholine levels and normalized the increased by scopolamine acetylcholine esterase activity in hippocampus. Most effective 5MeO was in counteracting the induced by scopolamine oxidative stress by decreasing the increased by scopolamine levels of lipid peroxidation and by increasing the reduced by scopolamine catalase activity. Blood biochemical analyses demonstrated a favorable safety profile of 5MeO, prompting further pharmacological studies suggesting 5MeO as a safe and efficient candidate in a multitargeted treatment of AD.

Beyond psychedelics: set and setting in general psychiatric practice

Psychedelic compounds continue gaining scientific and regulatory traction as potential new treatments for psychiatric disorders. While most psychiatrists will likely not work directly with these compounds, psychedelic research practices provide insights that may improve conventional psychiatric care. Through its emphasis on 'set and setting' (mindset and environment, respectively), psychedelic research highlights the importance of non-pharmacologic factors maximizing therapeutic outcomes. While psychedelics and serotonergic antidepressants are distinctly different in their subjective experience, new findings suggest mechanistic overlap between them. Both have been found to modulate neurotrophins, enhance neuroplasticity, and reopen critical periods of learning, molded by the environmental context in which they are administered.

This paper will argue that by integrating insights from psychedelic research (particularly set and setting), depression treatment outcomes in traditional psychiatric settings can improve by optimizing non-pharmacological factors in treatment, including the provision of high-quality psychotherapy.

Saroglitazar, a PPAR α/γ agonist alleviates 3-Nitropropionic acid induced neurotoxicity in rats: Unveiling the underlying mechanisms

Saroglitazar (SGZ), a peroxisomal proliferated activated receptor α/γ agonist showed neuroprotective effects in various neurodegenerative disorders like Alzheimer's and Parkinson's. However, no studies were performed on Huntington's, so the goal of the current study is to examine the effect of SGZ on Huntington's disease like symptoms induced by 3-Nitropropionic acid. In this protocol, twenty-four rats were divided into four groups, each group consisting of 6 animals. Group 1: The control group received 1 % CMC 10 mg/kg, p.o. for 14 days. Groups 2, 3, and 4 received 3-NP 15 mg/kg, i.p. from Day 1 to Day 7. Groups 3 and 4 received SGZ 5 mg/kg, p.o. and 10 mg/kg, p.o. respectively once daily from day 1 to day 14. Various behavioral tests like OFT, rotarod, hanging wire, narrow beam walk, MWM, and Y-maze were performed. On day-15, the animals were euthanised by cervical dislocation and brain sample were isolated for biochemical and histopathological analysis. Administration of 3-NP showed a significant decrease in motor coordination and cognitive function. Furthermore, 3-NP altered the activity of acetylcholinesterase, anti-oxidant enzymes, Nrf-2, NF-κB, BDNF, CREB levels, and histological features. However, treatment with SGZ showed ameliorative effects in the 3-NP induced neurotoxicity via PPAR α/γ pathway by reducing motor dysfunction, memory impairment, cholinesterase levels, oxidative stress, neuroinflammation. It also enhanced the levels of Nrf-2, BDNF, and CREB expression and improved histological features. In conclusion, treatment with Saroglitazar attenuated Huntington's disease-like symptoms in rats which are induced by 3-NP via activation of PPAR α/γ pathway.

Mannose-Functionalized Chitosan-Coated PLGA Nanoparticles for Brain-Targeted Codelivery of CBD and BDNF for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a common neurodegenerative disease causing cognitive and memory decline. AD is characterized by the deposition of amyloid-β and hypophosphorylated forms of tau protein. AD brains are found to be associated with neurodegeneration, oxidative stress, and inflammation. Cannabidiol (CBD) shows neuroprotective, antioxidant, and anti-inflammatory properties and simultaneously reduces amyloid-β production and tau hyperphosphorylation. The brain-derived neurotrophic factor (BDNF) plays a vital role in the development and maintenance of the plasticity of the central nervous system. A decline of BDNF levels in AD patients results in reduced plasticity and neuronal cell death. Current therapeutics against AD are limited to only symptomatic relief, necessitating a therapeutic strategy that reverses cognitive decline. In this scenario, combination therapy of CBD and BDNF could be a fruitful strategy for the treatment of AD. We designed mannose-conjugated chitosan-coated poly(d,l-lactide-co-glycolide (PLGA) (CHTMAN-PLGA) nanoparticles for the codelivery of CBD and BDNF to the brain. Chitosan is modified with mannose to specifically target the glucose transporter-1 (GLUT-1) receptor abundantly present in the blood-brain barrier for selectively delivering therapeutics to the brain. The CBD-encapsulated nanoparticles showed an average hydrodynamic diameter of 306 ± 8.12 nm and a zeta potential of 31.7 ± 1.53 mV. The coated nanoparticles prolonged encapsulated CBD release from the PLGA matrix. The coated nanoparticles exhibited sustained release of CBD for up to 22 days with 91.68 ± 2.91% release of the encapsulated drug. The coated nanoparticles, which had a high positive zeta potential (31.7 ± 1.53 mV), encapsulated the plasmid DNA. The qualitative transfection efficiency was investigated using CHTMAN-PLGA-CBD/pGFP in bEND.3, primary astrocytes, and primary neurons, while the quantitative transfection efficiency of the delivery system was determined using CHTMAN-PLGA-CBD/pBDNF. In vitro, the pBDNF transfection study revealed that the BDNF expression was 4-fold higher for CHTMAN-PLGA-CBD/pBDNF than for naked pBDNF in all of the cell lines. The cytotoxicity and hemocompatibility of the designed nanoparticles were tested in bEND.3 cells and red blood cells, respectively, and the nanoparticles were found to be nontoxic and hemocompatible. Hence, mannose-conjugated chitosan-coated PLGA nanoparticles could be useful as brain-targeting delivery vehicles for the codelivery of CBD and BDNF for possible AD treatment.

Treatment with walnut peptide ameliorates memory impairment in zebrafish and rats: promoting the expression of neurotrophic factors and suppressing oxidative stress

Walnut peptide, a low molecular weight peptide separated from walnuts by enzymatic hydrolysis, is considered as a potential nutraceutical with a variety of biological activities. In this study, we characterized the walnut peptide prepared by alkaline protease hydrolysis and evaluated its neuroprotective effect in zebrafish and rat models of memory disorders. Series of concentrations of the walnut peptide were orally administered to zebrafish and rats to examine its impact on the behavior and biochemical indicators. The results showed that the oral administration of walnut peptide significantly ameliorated the behavioral performance in zebrafish exposed to bisphenol AF (1 μg mL-1) and rats exposed to alcohol (30% ethanol, 10 mL kg-1). Furthermore, the walnut peptide upregulated the expression of neurotrophic-related molecules in zebrafish, such as the brain-derived neurotrophic factor (BDNF) and the glial cell-derived neurotrophic factor (GDNF). In the rat brain, the walnut peptide increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while dramatically reduced malondialdehyde (MDA) level. Together, these findings elucidated that the walnut peptide might partially offset the declarative memory deficits via regulation of neurotrophic-related molecule expression and promotion of the antioxidant defense ability. Therefore, walnut peptide holds the potential for development into functional foods as a nutritional supplement for the management of certain neurodegenerative disorders.

Controlled Hypoxia Acutely Prevents Physical Inactivity-Induced Peripheral BDNF Decline

Brain-derived neurotrophic factor (BDNF) is a crucial mediator of neuronal plasticity. Here, we investigated the effects of controlled normobaric hypoxia (NH) combined with physical inactivity on BDNF blood levels and executive functions. A total of 25 healthy adults (25.8 ± 3.3 years, 15 female) were analyzed in a randomized controlled cross-over study. Each intervention began with a 30 min resting phase under normoxia (NOR), followed by a 90 min continuation of NOR or NH (peripheral oxygen saturation [SpO2] 85-80%). Serum and plasma samples were collected every 15 min. Heart rate and SpO2 were continuously measured. Before and after each exposure, cognitive tests were performed and after 24 h another follow-up blood sample was taken. NH decreased SpO2 (p < 0.001, ηp2 = 0.747) and increased heart rate (p = 0.006, ηp2 = 0.116) significantly. The 30-min resting phase under NOR led to a significant BDNF reduction in serum (p < 0.001, ηp2 = 0.581) and plasma (p < 0.001, ηp2 = 0.362). Continuation of NOR further significantly reduced BDNF after another 45 min (p = 0.018) in serum and after 30 min (p = 0.040) and 90 min (p = 0.005) in plasma. There was no significant BDNF decline under NH. A 24 h follow-up examination showed a significant decline in serum BDNF, both after NH and NOR. Our results show that NH has the potential to counteract physical inactivity-induced BDNF decline. Therefore, our study emphasizes the need for a physically active lifestyle and its positive effects on BDNF. This study also demonstrates the need for a standardized protocol for future studies to determine BDNF in serum and plasma.

The vicious circle between homocysteine, methyl group-donating vitamins and chronic levodopa intake in Parkinson's disease

A biomarker for declined methylation capacity is elevation of homocysteine levels. They increase the risk for onset of vascular disease and contribute to progression of chronic neurodegeneration and aging. This narrative review discusses associations between homocysteine, consumption of methyl group-donating vitamins and impact on disease-generating mechanisms in levodopa-treated patients with Parkinson's disease. We conclude to recommend levodopa-treated patients to substitute themselves with methyl group-donating vitamins. This is harmless in terms of application of folic acid, methylcobalamin or hydroxocobalamin. Moreover, we suggest a crucial discussion on the value of the various popular hypotheses on Parkinson's disease-generating mechanisms. Findings from studies with acute levodopa exposure describe oxidative stress generation and impaired methylation capacity, which causes gene dysfunction. Their repeated occurrences contribute to onset of mitochondrial dysfunction, iron enrichment and pathologic protein accumulation in the long term. Current research underestimates these epigenetic, metabolic consequences of chronic levodopa application. Supplementary treatment strategies are recommended to avoid levodopa-related side effects.

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.

Cryogel microcarriers for sustained local delivery of growth factors to the brain

Neurotrophic growth factors such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) have been considered as potential therapeutic candidates for neurodegenerative disorders due to their important role in modulating the growth and survival of neurons. However, clinical translation remains elusive, as their large size hinders translocation across the blood-brain barrier (BBB), and their short half-life in vivo necessitates repeated administrations. Local delivery to the brain offers a potential route to the target site but requires a suitable drug-delivery system capable of releasing these proteins in a controlled and sustained manner. Herein, we develop a cryogel microcarrier delivery system which takes advantage of the heparin-binding properties of GDNF and BDNF, to reversibly bind/release these growth factors via electrostatic interactions. Droplet microfluidics and subzero temperature polymerization was used to create monodisperse cryogels with varying degrees of negative charge and an average diameter of 20 μm. By tailoring the inclusion of 3-sulfopropyl acrylate (SPA) as a negatively charged moiety, the release duration of these two growth factors could be adjusted to range from weeks to half a year. 80% SPA cryogels and 20% SPA cryogels were selected to load GDNF and BDNF respectively, for the subsequent biological studies. Cell culture studies demonstrated that these cryogel microcarriers were cytocompatible with neuronal and microglial cell lines, as well as primary neural cultures. Furthermore, in vivo studies confirmed their biocompatibility after administration into the brain, as well as their ability to deliver, retain and release GDNF and BDNF in the striatum. Overall, this study highlights the potential of using cryogel microcarriers for long-term delivery of neurotrophic growth factors to the brain for neurodegenerative disorder therapeutics.

Agomirs upregulating carboxypeptidase E expression rescue hippocampal neurogenesis and memory deficits in Alzheimer's disease

BACKGROUND

Adult neurogenesis occurs in the subventricular zone (SVZ) and the subgranular zone of the dentate gyrus in the hippocampus. The neuronal stem cells in these two neurogenic niches respond differently to various physiological and pathological stimuli. Recently, we have found that the decrement of carboxypeptidase E (CPE) with aging impairs the maturation of brain-derived neurotrophic factor (BDNF) and neurogenesis in the SVZ. However, it remains unknown whether these events occur in the hippocampus, and what the role of CPE is in the adult hippocampal neurogenesis in the context of Alzheimer's disease (AD).

METHODS

In vivo screening was performed to search for miRNA mimics capable of upregulating CPE expression and promoting neurogenesis in both neurogenic niches. Among these, two agomirs were further assessed for their effects on hippocampal neurogenesis in the context of AD. We also explored whether these two agomirs could ameliorate behavioral symptoms and AD pathology in mice, using direct intracerebroventricular injection or by non-invasive intranasal instillation.

RESULTS

Restoration of CPE expression in the hippocampus improved BDNF maturation and boosted adult hippocampal neurogenesis. By screening the miRNA mimics targeting the 5'UTR region of Cpe gene, we developed two agomirs that were capable of upregulating CPE expression. The two agomirs significantly rescued adult neurogenesis and cognition, showing multiple beneficial effects against the AD-associated pathologies in APP/PS1 mice. Of note, noninvasive approach via intranasal delivery of these agomirs improved the behavioral and neurocognitive functions of APP/PS1 mice.

CONCLUSIONS

CPE may regulate adult hippocampal neurogenesis via the CPE-BDNF-TrkB signaling pathway. This study supports the prospect of developing miRNA agomirs targeting CPE as biopharmaceuticals to counteract aging- and disease-related neurological decline in human brains.

Improvement of spatial learning and memory deficits by intranasal administration of human olfactory ecto-mesenchymal stem cells in an Alzheimer's disease rat model

Mesenchymal stem cells therapy provides a new perspective of therapeutic approaches in the treatment of neurodegenerative diseases. The present study aimed to investigate the effects of intranasally transplanted human "olfactory ecto-mesenchymal stem cells" (OE-MSCs) in Alzheimer's disease (AD) rats. In this study, we isolated OE-MSCs from human olfactory lamina propria and phenotypically characterized them using immunocytochemistry and flow cytometry. The undifferentiated OE-MSCs were transplanted either by intranasal (IN) or intrahippocampal (IH) injection to rat models of AD, which were induced by injecting amyloid-beta (Aβ) intrahippocampally. Behavioral, histological, and molecular assessments were performed after a three-month recovery period. Based on the results, intranasal administration of OE-MSCs significantly reduced Aβ accumulation and neuronal loss, improved learning and memory impairments, and increased levels of BDNF (brain-derived neurotrophic factor) and NMDAR (N-methyl-D-Aspartate receptors) in the AD rat model. These changes were more significant in animals who received OE-MSCs by intranasal injection. The results of this study suggest that OE-MSCs have the potential to enhance cognitive function in AD, possibly mediated by BDNF and the NMDA receptors.

Single-cell RNA-seq data analysis reveals functionally relevant biomarkers of early brain development and their regulatory footprints in human embryonic stem cells (hESCs)

The complicated process of neuronal development is initiated early in life, with the genetic mechanisms governing this process yet to be fully elucidated. Single-cell RNA sequencing (scRNA-seq) is a potent instrument for pinpointing biomarkers that exhibit differential expression across various cell types and developmental stages. By employing scRNA-seq on human embryonic stem cells, we aim to identify differentially expressed genes (DEGs) crucial for early-stage neuronal development. Our focus extends beyond simply identifying DEGs. We strive to investigate the functional roles of these genes through enrichment analysis and construct gene regulatory networks to understand their interactions. Ultimately, this comprehensive approach aspires to illuminate the molecular mechanisms and transcriptional dynamics governing early human brain development. By uncovering potential links between these DEGs and intelligence, mental disorders, and neurodevelopmental disorders, we hope to shed light on human neurological health and disease. In this study, we have used scRNA-seq to identify DEGs involved in early-stage neuronal development in hESCs. The scRNA-seq data, collected on days 26 (D26) and 54 (D54), of the in vitro differentiation of hESCs to neurons were analyzed. Our analysis identified 539 DEGs between D26 and D54. Functional enrichment of those DEG biomarkers indicated that the up-regulated DEGs participated in neurogenesis, while the down-regulated DEGs were linked to synapse regulation. The Reactome pathway analysis revealed that down-regulated DEGs were involved in the interactions between proteins located in synapse pathways. We also discovered interactions between DEGs and miRNA, transcriptional factors (TFs) and DEGs, and between TF and miRNA. Our study identified 20 significant transcription factors, shedding light on early brain development genetics. The identified DEGs and gene regulatory networks are valuable resources for future research into human brain development and neurodevelopmental disorders.

Sourdough bread as nutritional intervention tool for improvement of cognitive dysfunction in diabetic rats

BACKGROUND

The current research targeted to study the impact of nutritional intervention by two sourdough breads in improvement of cognitive dysfunction in diabetic rats.

METHODS

Type-2 diabetes was induced in rats by Streptozotocin-Nicotinamide (STZ-NC). Diabetic rats were fed on balanced diet or balanced diet containing 20% of sourdough bread I or II for a month. Lipid profile, oxidative stress, inflammatory markers and cognitive functions were assessed in all rats. Gene expression of brain-derived neurotrophic factor (BDNF) and nuclear respiratory factor 2 (NRF-2) were assessed in hippocampal tissue, while expression of phosphoenol pyruvate carboxy kinase (PEPCK), and glucose transporter 2 (GLUT2) genes were evaluated in hepatic tissue. Chemical composition and fatty acids profile were evaluated in the prepared sourdough bread.

RESULTS

Sourdough bread II showed higher content of phenolic compounds, fat, fiber and carbohydrates. Fatty acids profile revealed that sourdough bread I was higher in saturated fatty acids (16.08%), while sourdough bread sample II was higher in unsaturated fatty acids (79.33%). Sourdough bread I or II feeding rats' showed significant improvement in hyperglycemia, oxidative stress markers, inflammatory markers, lipid profile, liver and kidney functions in association with improvement in cognitive function. Gene expression of BDNF and NRF2 in hippocampal tissue were increased significantly, while hepatic GLUT2 and PEPCK gene expression were down-regulated in diabetic given sourdough bread I or II.

CONCLUSION

Sourdough bread II was superior in all the studied parameters. The anti-diabetic effect and protection from cognitive dysfunction of sourdough bread samples may be ascribed to the occurrence of dietary fibers, phenolic compounds, and polyunsaturated fatty acids.

An in vitro analysis of an innovative standardized phospholipid carrier-based Melissa officinalis L. extract as a potential neuromodulator for emotional distress and related conditions

Background: Melissa officinalis L. (MO), commonly known as lemon balm, a member of the mint family, is considered a calming herb. In various traditional medicines, it has been utilized to reduce stress and anxiety and promote sleep. A growing body of clinical evidence suggests that MO leaf extract supplementation possesses considerable neuropharmacological properties. However, its possible mechanism of action largely remains unknown. Objective: In the present in vitro studies, we comparatively investigated the central nervous system (CNS)-calming and antioxidative stress properties of an innovative standardized phospholipid carrier-based (Phytosome™) MO extract (Relissa™) vs. an unformulated dry MO extract. Methods: The neuropharmacological effect of the extract was studied in the anti-depressant enzymes γ-aminobutyrate transaminase (GABA-T) and monoamine oxidase A (MAO-A) assays and SH-SY5Y cells brain-derived neurotrophic factor (BDNF) expression assay. The neuroprotective effect of the extract against oxidative stress was assessed in SH-SY5Y cell-based (H2O2-exposed) Total Antioxidant Status (TAS) and Total Reactive Oxygen Species (ROS) assays. The cytotoxic effect of the extract was evaluated using MTT and LDH assays. The extract antioxidant effect was also evaluated in cell-free chemical tests, including TEAC-ABTS, DPPH, Ferric Reducing Antioxidant Power (FRAP), Oxygen Radical Antioxidant Capacity (ORAC), and Hydroxyl Radical Antioxidant Capacity (HORAC) assays. Results: Relissa™ exhibited high GABA-T inhibitory activity, IC50 (mg/mL) = 0.064 vs. unformulated dry MO extract, IC50 (mg/mL) = 0.27. Similar inhibitory effects were also observed for MAO-A. Relissa™ demonstrated an improved neuroprotective antioxidant effect on SH-SY5Y cells against H2O2-induced oxidative stress. Compared to unformulated dry MO extract, Relissa™ exerted high protective effect on H2O2-exposed SH-SY5Y cells, leading to higher cells BDNF expression levels. Moreover, cell-free chemical tests, including TEAC-ABTS, DPPH radical scavenging, FRAP, ORAC, and HORAC assays, validated the improved antioxidant effect of Relissa™ vs. unformulated dry MO extract. Conclusion: The results of the present study support the neuromodulating and neuroprotective properties of Relissa™, and its supplementation may help in the amelioration of emotional distress and related conditions.

Brain-derived neuerotrophic factor and related mechanisms that mediate and influence progesterone-induced neuroprotection

Historically, progesterone has been studied significantly within the context of reproductive biology. However, there is now an abundance of evidence for its role in regions of the central nervous system (CNS) associated with such non-reproductive functions that include cognition and affect. Here, we describe mechanisms of progesterone action that support its brain-protective effects, and focus particularly on the role of neurotrophins (such as brain-derived neurotrophic factor, BDNF), the receptors that are critical for their regulation, and the role of certain microRNA in influencing the brain-protective effects of progesterone. In addition, we describe evidence to support the particular importance of glia in mediating the neuroprotective effects of progesterone. Through this review of these mechanisms and our own prior published work, we offer insight into why the effects of a progestin on brain protection may be dependent on the type of progestin (e.g., progesterone versus the synthetic, medroxyprogesterone acetate) used, and age, and as such, we offer insight into the future clinical implication of progesterone treatment for such disorders that include Alzheimer's disease, stroke, and traumatic brain injury.

Finding biomarkers of experience in animals

At a time when there is a growing public interest in animal welfare, it is critical to have objective means to assess the way that an animal experiences a situation. Objectivity is critical to ensure appropriate animal welfare outcomes. Existing behavioural, physiological, and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes. But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal, from negative to positive. In this review, we draw from the knowledge of human biomedical science to propose a list of candidate biological markers (biomarkers) that should reflect the experiential state of non-human animals. The proposed biomarkers can be classified on their main function as endocrine, oxidative stress, non-coding molecular, and thermobiological markers. We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.

The hormesis principle of neuroplasticity and neuroprotection

Animals live in habitats fraught with a range of environmental challenges to their bodies and brains. Accordingly, cells and organ systems have evolved stress-responsive signaling pathways that enable them to not only withstand environmental challenges but also to prepare for future challenges and function more efficiently. These phylogenetically conserved processes are the foundation of the hormesis principle, in which single or repeated exposures to low levels of environmental challenges improve cellular and organismal fitness and raise the probability of survival. Hormetic principles have been most intensively studied in physical exercise but apply to numerous other challenges known to improve human health (e.g., intermittent fasting, cognitive stimulation, and dietary phytochemicals). Here we review the physiological mechanisms underlying hormesis-based neuroplasticity and neuroprotection. Approaching natural resilience from the lens of hormesis may reveal novel methods for optimizing brain function and lowering the burden of neurological disorders.

The regulatory role of BDNF in neuroimmune axis function and neuroinflammation induced by chronic stress: A new therapeutic strategies for neurodegenerative disorders

Neurodegenerative disorders account for a high proportion of neurological diseases that significantly threaten public health worldwide. Various factors are involved in the pathophysiology of such diseases which can lead to neurodegeneration and neural damage. Furthermore, neuroinflammation is a well-known factor in predisposing factors of neurological and especially neurodegenerative disorders which can be strongly suppressed by "anti-inflammatory" actions of brain-derived neurotrophic factor (BDNF). Stress has has also been identified as a risk factor in developing neurodegenerative disorders potentially leading to increased neuroinflammation in the brain and progressive loss in neuronal structures and impaired functions in the CNS. Recently, more studies have increasingly been focused on the role of neuroimmune system in regulating the neurobiology of stress. Emerging evidence indicate that exposure to chronic stress might alter the susceptibility to neurodegeneration via influencing the microglia function. Microglia is considered as the first responding group of cells in suppressing neuroinflammation, leading to an increased inflammatory cytokine signaling that promote the synaptic plasticity deficiencies, impairment in neurogenesis, and development of neurodegenerative disorders. In this review we discuss how exposure to chronic stress might alter the neuroimmune response potentially leading to progress of neurodegenerative disorders. We also emphasize on the role of BDNF in regulating the neuroimmune axis function and microglia modulation in neurodegenerative disorders.

Isolation and Identification of the High-Affinity DNA Aptamer Target to the Brain-Derived Neurotrophic Factor (BDNF)

Aptamers are functional oligonucleotide ligands used for the molecular recognition of various targets. The natural characteristics of aptamers make them an excellent alternative to antibodies in diagnostics, therapeutics, and biosensing. DNA aptamers are mainly single-stranded oligonucleotides (ssDNA) that possess a definite binding to targets. However, the application of aptamers to the fields of brain health and neurodegenerative diseases has been limited to date. Herein, a DNA aptamer against the brain-derived neurotrophic factor (BDNF) protein was obtained by in vitro selection. BDNF is a potential biomarker of brain health and neurodegenerative diseases and has functions in the synaptic plasticity and survival of neurons. We identified eight aptamers that have binding affinity for BDNF from a 50-nucleotide library. Among these aptamers, NV_B12 showed the highest sensitivity and selectivity for detecting BDNF. In an aptamer-linked immobilized sorbent assay (ALISA), the NV_B12 aptamer strongly bound to BDNF protein, in a dose-dependent manner. The dissociation constant (Kd) for NV_B12 was 0.5 nM (95% CI: 0.4-0.6 nM). These findings suggest that BDNF-specific aptamers could be used as an alternative to antibodies in diagnostic and detection assays for BDNF.

Physical Exercise as an Intervention for Depression: Evidence for Efficacy and Mu-Opioid Receptors as a Mechanism of Action

Physical exercise is often cited as an important part of an intervention for depression, and there is empirical evidence to support this. However, the mechanism of action through which any potential antidepressant effects are produced is not widely understood. Recent evidence points toward the involvement of endogenous opioids, and especially the mu-opioid system, as a partial mediator of these effects. In this chapter, we discuss the current level of empirical support for physical exercise as either an adjunctive or standalone intervention for depression. We then review the extant evidence for involvement of endogenous opioids in the proposed antidepressant effects of exercise, with a focus specifically on evidence for mu-opioid system involvement.

BDNF and Cerebellar Ataxia

Brain-derived neurotrophic factor (BDNF) has been proposed as a treatment for neurodegeneration, including diseases of the cerebellum, where BDNF levels or those of its main receptor, TrkB, are often diminished relative to controls, thereby serving as replacement therapy. Experimental evidence indicates that BDNF signaling countered cerebellar degeneration, sensorimotor deficits, or both, in transgenic ATXN1 mice mutated for ataxin-1, Cacna1a knock-in mice mutated for ataxin-6, mice injected with lentivectors encoding RNA sequences against human FXN into the cerebellar cortex, Kcnj6Wv (Weaver) mutant mice with granule cell degeneration, and rats with olivocerebellar transaction, similar to a BDNF-overexpressing transgenic line interbred with Cacng2stg mutant mice. In this regard, this study discusses whether BDNF is effective in cerebellar pathologies where BDNF levels are normal and whether it is effective in cases with combined cerebellar and basal ganglia damage.

TrkB/BDNF signaling pathway and its small molecular agonists in CNS injury

As one of the most prevalent neurotrophic factors in the central nervous system (CNS), brain-derived neurotrophic factor (BDNF) plays a significant role in CNS injury by binding to its specific receptor Tropomyosin-related kinase receptor B (TrkB). The BDNF/TrkB signaling pathway is crucial for neuronal survival, structural changes, and plasticity. BDNF acts as an axonal growth and extension factor, a pro-survival factor, and a synaptic modulator in the CNS. BDNF also plays an important role in the maintenance and plasticity of neuronal circuits. Several studies have demonstrated the importance of BDNF in the treatment and recovery of neurodegenerative and neurotraumatic disorders. By undertaking in-depth study on the mechanism of BDNF/TrkB function, important novel therapeutic strategies for treating neuropsychiatric disorders have been discovered. In this review, we discuss the expression patterns and mechanisms of the TrkB/BDNF signaling pathway in CNS damage and introduce several intriguing small molecule TrkB receptor agonists produced over the previous several decades.

Brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling in spinal muscular atrophy and amyotrophic lateral sclerosis

Tropomyosin receptor kinase B (TrkB) and its primary ligand brain-derived neurotrophic factor (BDNF) are expressed in the neuromuscular system, where they affect neuronal survival, differentiation, and functions. Changes in BDNF levels and full-length TrkB (TrkB-FL) signaling have been revealed in spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), two common forms of motor neuron diseases that are characterized by defective neuromuscular junctions in early disease stages and subsequently progressive muscle weakness. This review summarizes the current understanding of BDNF/TrkB-FL-related research in SMA and ALS, with an emphasis on their alterations in the neuromuscular system and possible BDNF/TrkB-FL-targeting therapeutic strategies. The limitations of current studies and future directions are also discussed, giving the hope of discovering novel and effective treatments.

Neurotrophic Factors in Cannabis-induced Psychosis: An Update

BACKGROUND

Cannabis is the most widely used illicit substance. Numerous scientific evidence confirm the strong association between cannabis and psychosis. Exposure to cannabis can induce the development of psychosis and schizophrenia in vulnerable individuals. However, the neurobiological processes underlying this relationship are unknown. Neurotrophins are a class of proteins that serve as survival factors for central nervous system (CNS) neurons. In particular, Nerve Growth Factor (NGF) plays an important role in the survival and function of cholinergic neurons while Brain Derived Neurotrophic Factor (BDNF) is involved in synaptic plasticity and the maintenance of midbrain dopaminergic and cholinergic neurons. Glial Cell Derived Neurotrophic Factor (GDNF) promotes the survival of midbrain dopaminergic neurons and Neuregulin 1 (NrG- 1) contributes to glutamatergic signals regulating the N-methyl-D-aspartate (NMDA). They have a remarkable influence on the neurons involved in the Δ-9-THC (tethra-hydro-cannabinol) action, such as dopaminergic and glutamatergic neurons, and can play dual roles: first, in neuronal survival and death, and, second, in activity-dependent plasticity.

METHODS

In this brief update, reviewing in a narrative way the relevant literature, we will focus on the effects of cannabis on this class of proteins, which may be implicated, at least in part, in the mechanism of the psychostimulant-induced neurotoxicity and psychosis.

CONCLUSION

Since altered levels of neurotrophins may participate in the pathogenesis of psychotic disorders which are common in drug users, one possible hypothesis is that repeated cannabis exposure can cause psychosis by interfering with neurotrophins synthesis and utilization by CNS neurons.

Topical Cellular/Tissue and Molecular Aspects Regarding Nonpharmacological Interventions in Alzheimer's Disease-A Systematic Review

One of the most complex and challenging developments at the beginning of the third millennium is the alarming increase in demographic aging, mainly-but not exclusively-affecting developed countries. This reality results in one of the harsh medical, social, and economic consequences: the continuously increasing number of people with dementia, including Alzheimer's disease (AD), which accounts for up to 80% of all such types of pathology. Its large and progressive disabling potential, which eventually leads to death, therefore represents an important public health matter, especially because there is no known cure for this disease. Consequently, periodic reappraisals of different therapeutic possibilities are necessary. For this purpose, we conducted this systematic literature review investigating nonpharmacological interventions for AD, including their currently known cellular and molecular action bases. This endeavor was based on the PRISMA method, by which we selected 116 eligible articles published during the last year. Because of the unfortunate lack of effective treatments for AD, it is necessary to enhance efforts toward identifying and improving various therapeutic and rehabilitative approaches, as well as related prophylactic measures.

Sericin alleviates motor dysfunction by modulating inflammation and TrkB/BDNF signaling pathway in the rotenone-induced Parkinson's disease model

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of nigrostriatal dopaminergic neurons and movement impairment. Based on theories, neuroinflammatory processes may be vital in the etiology of PD and other neurodegenerative diseases. Reports show that rotenone has neurotoxic, inflammatory, and motor impairment effects in PD. Sericin is a natural polymer with effective properties, such as neuroprotective and anti-inflammatory. Therefore, this study aimed to examine the effects of sericin administration on motor dysfunction by modulating inflammation and tyrosine kinase B/brain-derived neurotrophic factor (TrkB/BDNF) pathway in the rotenone-induced PD model.

METHODS

Wistar male rats (3-months-old) were treated with rotenone (2 mg/kg every 48 h for 30 days) to induce a rotenone-induced PD model. Also, sericin was administered orally at dose of 200 mg/kg every 48 h for 30 days. Rotarod and bar tests were performed for motor dysfunction. The protein levels of BDNF, c-fos, TrkB, tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6) and catalase activity were evaluated in the striatum area.

RESULTS

Results showed that sericin increased latent time in the rotarod test and decreased the time staying on the pole in the bar test compared to the PD group (P < 0.001 for both tests). Moreover, sericin treatments decreased TNF-α (P < 0.001) and IL-6 (P < 0.001) concentration levels and enhanced the levels of BDNF (P < 0.001), c-fos (P < 0.001), TrkB (P < 0.001) proteins and catalase activity (P < 0.05) in the striatum area compared to the PD group.

CONCLUSION

These results support a protective benefit of sericin therapy in a rotenone-induced PD paradigm by reducing motor impairment, inflammatory response, and disruption of the TrkB/BDNF signaling pathway.

The potential role of cholesterol in Parkinson's disease neuropathology: perpetrator or victim

Parkinson's disease (PD) is a neurodegenerative disease characterized by deposition of α-synuclein and aggregation of Lewy bodies. Cholesterol is involved with PD neuropathology in bidirectional ways that could be protective or harmful. Thus, the objective of the present review was to verify the potential role of cholesterol in PD neuropathology. Deregulation of ion channels and receptors induced by cholesterol alteration suggests a possible mechanism for the neuroprotective effects of cholesterol against PD development. However, high serum cholesterol level increases PD risk indirectly by 27-hydroxycholesterol which induces oxidative stress, inflammation, and apoptosis. Besides, hypercholesterolemia triggers the accumulation of cholesterol in macrophages and immune cells leading to the release of pro-inflammatory cytokines with progression of neuroinflammation subsequently. Additionally, cholesterol increases aggregation of α-synuclein and induces degeneration of dopaminergic neurons (DN) in the substantia nigra (SN). Hypercholesterolemia may lead to cellular Ca2+ overload causing synaptic and the development of neurodegeneration. In conclusion, cholesterol has bidirectional effects on PD neuropathology and might be protective or harmful.

New insights on the potential effect of vinpocetine in Parkinson's disease: one of the neglected warden and baffling topics

Vinpocetine (VPN) is an ethyl apovincaminate that has anti-inflammatory and antioxidant effects by inhibiting the expression of nuclear factor kappa B (NF-κB) and phosphodiesterase enzyme 1 (PDE-1). VPN is used in the management of stroke, dementia, and other neurodegenerative brain diseases. VPN may be effective in treating Parkinson's disease (PD). Therefore, this review aimed to clarify the mechanistic role of VPN in the management of PD. VPN has protective and restorative effects against neuronal injury by reducing neuroinflammation, and improvement of synaptic plasticity and cerebral blood flow. VPN protects dopaminergic neurons by reducing oxidative stress, lipid peroxidation, glutamate neurotoxicity, and regulation of Ca+ 2 overloads. VPN can alleviate PD neuropathology through its anti-inflammatory, antioxidant, antiapoptotic and neurogenic effects. VPN through inhibition of PDE1 improves cyclic adenosine monophosphate (cAMP)/cyclic guanosine monophosphate (cGMP) signaling in the dopaminergic neurons of the substantia nigra (SN). VPN improves PD neuropathology through PDE1 inhibition with a subsequent increase of the cAMP/cGMP signaling pathway. Therefore, increasing cAMP leads to antioxidant effects, while augmentation of cGMP by VPN leads to anti-inflammatory effects which reduced neurotoxicity and development of motor severity in PD. In conclusion, this review indicated that VPN could be effective in the management of PD.

Exploring Rosiglitazone's Potential to Treat Alzheimer's Disease through the Modulation of Brain-Derived Neurotrophic Factor

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that debilitates over 55 million individuals worldwide. Currently, treatments manage and alleviate its symptoms; however, there is still a need to find a therapy that prevents or halts disease progression. Since AD has been labeled as "type 3 diabetes" due to its similarity in pathological hallmarks, molecular pathways, and comorbidity with type 2 diabetes mellitus (T2DM), there is growing interest in using anti-diabetic drugs for its treatment. Rosiglitazone (RSG) is a peroxisome proliferator-activated receptor-gamma agonist that reduces hyperglycemia and hyperinsulinemia and improves insulin signaling. In cellular and rodent models of T2DM-associated cognitive decline and AD, RSG has been reported to improve cognitive impairment and reverse AD-like pathology; however, results from human clinical trials remain consistently unsuccessful. RSG has also been reported to modulate the expression of brain-derived neurotrophic factor (BDNF), a protein that regulates neuroplasticity and energy homeostasis and is implicated in both AD and T2DM. The present review investigates RSG's limitations and potential therapeutic benefits in pre-clinical models of AD through its modulation of BDNF expression.

A review of combined neuromodulation and physical therapy interventions for enhanced neurorehabilitation

Rehabilitation approaches for individuals with neurologic conditions have increasingly shifted toward promoting neuroplasticity for enhanced recovery and restoration of function. This review focuses on exercise strategies and non-invasive neuromodulation techniques that target neuroplasticity, including transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), and peripheral nerve stimulation (PNS). We have chosen to focus on non-invasive neuromodulation techniques due to their greater potential for integration into routine clinical practice. We explore and discuss the application of these interventional strategies in four neurological conditions that are frequently encountered in rehabilitation settings: Parkinson's Disease (PD), Traumatic Brain Injury (TBI), stroke, and Spinal Cord Injury (SCI). Additionally, we discuss the potential benefits of combining non-invasive neuromodulation with rehabilitation, which has shown promise in accelerating recovery. Our review identifies studies that demonstrate enhanced recovery through combined exercise and non-invasive neuromodulation in the selected patient populations. We primarily focus on the motor aspects of rehabilitation, but also briefly address non-motor impacts of these conditions. Additionally, we identify the gaps in current literature and barriers to implementation of combined approaches into clinical practice. We highlight areas needing further research and suggest avenues for future investigation, aiming to enhance the personalization of the unique neuroplastic responses associated with each condition. This review serves as a resource for rehabilitation professionals and researchers seeking a comprehensive understanding of neuroplastic exercise interventions and non-invasive neuromodulation techniques tailored for specific diseases and diagnoses.

Vitamin E and Its Molecular Effects in Experimental Models of Neurodegenerative Diseases

With the advancement of in vivo studies and clinical trials, the pathogenesis of neurodegenerative diseases has been better understood. However, gaps still need to be better elucidated, which justifies the publication of reviews that explore the mechanisms related to the development of these diseases. Studies show that vitamin E supplementation can protect neurons from the damage caused by oxidative stress, with a positive impact on the prevention and progression of neurodegenerative diseases. Thus, this review aims to summarize the scientific evidence of the effects of vitamin E supplementation on neuroprotection and on neurodegeneration markers in experimental models. A search for studies published between 2000 and 2023 was carried out in the PubMed, Web of Science, Virtual Health Library (BVS), and Embase databases, in which the effects of vitamin E in experimental models of neurodegeneration were investigated. A total of 5669 potentially eligible studies were identified. After excluding the duplicates, 5373 remained, of which 5253 were excluded after checking the titles, 90 articles after reading the abstracts, and 11 after fully reviewing the manuscripts, leaving 19 publications to be included in this review. Experiments with in vivo models of neurodegenerative diseases demonstrated that vitamin E supplementation significantly improved memory, cognition, learning, motor function, and brain markers associated with neuroregeneration and neuroprotection. Vitamin E supplementation reduced beta-amyloid (Aβ) deposition and toxicity in experimental models of Alzheimer's disease. In addition, it decreased tau-protein hyperphosphorylation and increased superoxide dismutase and brain-derived neurotrophic factor (BDNF) levels in rodents, which seems to indicate the potential use of vitamin E in preventing and delaying the progress of degenerative lesions in the central nervous system.

Exerkines and redox homeostasis

Exercise physiology has gained increasing interest due to its wide effects to promote health. Recent years have seen a growth in this research field also due to the finding of several circulating factors that mediate the effects of exercise. These factors, termed exerkines, are metabolites, growth factors, and cytokines secreted by main metabolic organs during exercise to regulate exercise systemic and tissue-specific effects. The metabolic effects of exerkines have been broadly explored and entail a promising target to modulate beneficial effects of exercise in health and disease. However, exerkines also have broad effects to modulate redox signaling and homeostasis in several cellular processes to improve stress response. Since redox biology is central to exercise physiology, this review summarizes current evidence for the cross-talk between redox biology and exerkines actions. The role of exerkines in redox biology entails a response to oxidative stress-induced pathological cues to improve health outcomes and to modulate exercise adaptations that integrate redox signaling.

Exercise-induced hypothalamic neuroplasticity: Implications for energy and glucose metabolism

BACKGROUND

Neuroplasticity refers to the brain's ability to undergo functional and structural changes in response to diverse challenges. Converging evidence supports the notion that exercise serves as a metabolic challenge, triggering the release of multiple factors both in the periphery and within the brain. These factors actively contribute to plasticity in the brain, and in turn, regulate energy and glucose metabolism.

SCOPE OF REVIEW

The primary focus of this review is to explore the impact of exercise-induced plasticity in the brain on metabolic homeostasis, with an emphasis on the role of the hypothalamus in this process. Additionally, the review provides an overview of various factors induced by exercise that contribute to energy balance and glucose metabolism. Notably, these factors exert their effects, at least in part, through actions within the hypothalamus and more broadly in the central nervous system.

MAJOR CONCLUSIONS

Exercise elicits both transient and sustained changes in metabolism, accompanied by changes in neural activity within specific brain regions. Importantly, the contribution of exercise-induced plasticity and the underlying mechanisms by which neuroplasticity influences the effects of exercise are not well understood. Recent work has begun to overcome this gap in knowledge by examining the complex interactions of exercise-induced factors which alter neural circuit properties to influence metabolism.

The impact of regional heterogeneity in whole-brain dynamics in the presence of oscillations

Large variability exists across brain regions in health and disease, considering their cellular and molecular composition, connectivity, and function. Large-scale whole-brain models comprising coupled brain regions provide insights into the underlying dynamics that shape complex patterns of spontaneous brain activity. In particular, biophysically grounded mean-field whole-brain models in the asynchronous regime were used to demonstrate the dynamical consequences of including regional variability. Nevertheless, the role of heterogeneities when brain dynamics are supported by synchronous oscillating state, which is a ubiquitous phenomenon in brain, remains poorly understood. Here, we implemented two models capable of presenting oscillatory behavior with different levels of abstraction: a phenomenological Stuart-Landau model and an exact mean-field model. The fit of these models informed by structural- to functional-weighted MRI signal (T1w/T2w) allowed us to explore the implication of the inclusion of heterogeneities for modeling resting-state fMRI recordings from healthy participants. We found that disease-specific regional functional heterogeneity imposed dynamical consequences within the oscillatory regime in fMRI recordings from neurodegeneration with specific impacts on brain atrophy/structure (Alzheimer's patients). Overall, we found that models with oscillations perform better when structural and functional regional heterogeneities are considered, showing that phenomenological and biophysical models behave similarly at the brink of the Hopf bifurcation.

Model-based whole-brain perturbational landscape of neurodegenerative diseases

The treatment of neurodegenerative diseases is hindered by lack of interventions capable of steering multimodal whole-brain dynamics towards patterns indicative of preserved brain health. To address this problem, we combined deep learning with a model capable of reproducing whole-brain functional connectivity in patients diagnosed with Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD). These models included disease-specific atrophy maps as priors to modulate local parameters, revealing increased stability of hippocampal and insular dynamics as signatures of brain atrophy in AD and bvFTD, respectively. Using variational autoencoders, we visualized different pathologies and their severity as the evolution of trajectories in a low-dimensional latent space. Finally, we perturbed the model to reveal key AD- and bvFTD-specific regions to induce transitions from pathological to healthy brain states. Overall, we obtained novel insights on disease progression and control by means of external stimulation, while identifying dynamical mechanisms that underlie functional alterations in neurodegeneration.

Agomelatine attenuates cisplatin-induced cognitive impairment via modulation of BDNF/TrkB signaling in rat hippocampus

Cisplatin is a drug used effectively in the treatment of malignant tumors. However, cisplatin has many side effects, including cognitive impairment. Agomelatine, a synthetic melatonin analogue, is an important antidepressant. Increasing evidence has shown that agomelatine may be a potential neuroprotective agent. The aim of this study was to investigate the effect of agomelatine on learning and memory functions in cisplatin-induced cognitive impairment in a rat model. Male rats were administered agomelatine and cisplatin for 4 weeks. Neurobehavioral tests were performed at the end of the 4th week. After behavioral tests, rats were euthanized and BDNF, TNF, IL-1β, MDA and GSH levels were measured in hippocampal homegenates by ELISA. In addition, nNOS and TrkB receptor activity were measured immunohistochemically. The results showed that agomelatine significantly improved cognitive functions in spatial memory tests in rats with cisplatin-induced cognitive impairment. In addition, agomelatine treatment positively affected the discrimination index (DI). On the other hand, agomelatine treatment elevated cisplatin-suppressed hippocampal BDNF levels. Agomelatine treatment reduced cisplatin-induced neuroinflammation by suppressing TNF and IL-1β levels. Similarly, agomelatine reduced oxidative stress in the hippocampus. Histological findings showed that agomelatine treatment reduced pyramidal neuron damage in hippocampal DG, CA1 and CA3. Cisplatin increased nNOS and TrkB positivity in DG, CA1 and CA3 neurons compared to control. In contrast, agomelatine treatment decreased both nNOS and TrkB positive scores. These findings indicate that agomelatine reduces cisplatin-related cognitive impairment by exerting anti-inflammatory action and possibly by the modulation of the BDNF/TrkB/nNOS pathways in the hippocampus.

Brain-Derived Neurotrophic Factor: A Novel Dynamically Regulated Therapeutic Modulator in Neurological Disorders

The growth factor brain-derived neurotrophic factor (BDNF), and its receptor tropomyosin-related kinase receptor type B (TrkB) play an active role in numerous areas of the adult brain, where they regulate the neuronal activity, function, and survival. Upregulation and downregulation of BDNF expression are critical for the physiology of neuronal circuits and functioning in the brain. Loss of BDNF function has been reported in the brains of patients with neurodegenerative or psychiatric disorders. This article reviews the BDNF gene structure, transport, secretion, expression and functions in the brain. This article also implicates BDNF in several brain-related disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, major depressive disorder, schizophrenia, epilepsy and bipolar disorder.

A retrospective evaluation of the Brain and Body Fitness Studio service on functional capacity and quality of life in people with neurological disorders

Background

People with neurological disorders (ND) are less physically active than the general population due to physical, sensory, and/or cognitive impairments. These individuals often feel intimidated to join mainstream health and wellness centers due to lack of specialized support for people with ND. The Brain and Body Fitness Studio (BBFS) is one of the first Accredited Exercise Physiologist-led interprofessional services in Adelaide South Australia to provide individualized evidence-based multimodal exercise prescription and social support for this population. This comprehensive retrospective study evaluated the impact of BBFS on functional capacity (FC) determined as the 6-min walk distance (6 MWD) achieved during a 6-min walk test (6 MWT), of its members with ND.

Methods

Sixty-two BBFS members (age, 66 ± 10 years; 60% male) with ND (85% Parkinson's Disease; average time since diagnosis, 4 years [IQR, 2 to 12 years]) and complete pre- and post-6-month clinical assessment of the primary outcome of the study, the 6 MWD, were included in this retrospective analysis. A series of sub-analyses were also performed to investigate the effects of adherence to the recommended prescription of at least twice a week in the program (≥80 vs. < 80% adherence), and disease stage (time since diagnosis; ≥6 vs. < 6 years) on FC.

Results

Although there was no statistically significant change in 6 MWD from pre- to post-6-month BBFS program (+15 ± 90 m, p = 0.19), a clinically meaningful improvement of >14 m was evident. Improvement in 6 MWD was significantly greater in members who attended at least 80% of the recommended visits (≥80% visits, +37 ± 58 m; ≤ 80% visits,-1 ± 105 m, p = 0.046). We also found a 6 MWD improvement from pre- to post-6 months in those in the early years of their ND (< 6 years since diagnosis, +39 ± 76 m), but not in those in the later years of their ND (≥6 years since diagnosis, -36 ± 123 m, between group difference, p = 0.029).

Conclusion

A clinically meaningful 6 MWD improvement may be elicited by services provided by BBFS in people with ND. Overall, the benefits appear to be more evident in members who attended the BBFS for at least 80% of the recommended visits and those who were in the early stage of their ND diagnosis.

Difference in Methylation and Expression of Brain-Derived Neurotrophic Factor in Alzheimer's Disease and Mild Cognitive Impairment

Due to the increasing number of progressive dementias in the population, numerous studies are being conducted that seek to determine risk factors, biomarkers and pathological mechanisms that could help to differentiate between normal symptoms of aging, mild cognitive impairment (MCI) and dementia. The aim of this study was to investigate the possible association of levels of BDNF and COMT gene expression and methylation in peripheral blood cells with the development of Alzheimer's disease (AD). Our results revealed higher expression levels of BDNF (p < 0.001) in MCI subjects compared to individuals diagnosed with AD. However, no difference in COMT gene expression (p = 0.366) was detected. DNA methylation of the CpG islands and other sequences with potential effects on gene expression regulation revealed just one region (BDNF_9) in the BDNF gene (p = 0.078) with marginally lower levels of methylation in the AD compared to MCI subjects. Here, we show that the level of BDNF expression in the periphery is decreased in subjects with AD compared to individuals with MCI. The combined results from the gene expression analysis and DNA methylation analysis point to the potential of BDNF as a marker that could help distinguish between MCI and AD patients.

Ageing and the Autonomic Nervous System

The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.

Emotional and Affective Disorders in Cognitive Aging

The increased aging population who have aging-related diseases poses a serious challenge to health services, including mental health services. Due to the changes of body, brain, living environment, and lifestyle, the elderly will have different psychological changes from other age stages, some of which would develop into mental disorders, and affect the cognition of the elderly in turn. This elderly mental health condition has drawn wide attention from scientists. This chapter introduces the two most common emotional and affective disorders, late-life depression and anxiety, and focuses on their epidemiology and impact on the elderly. Furthermore, this chapter also reviews the effects of these two disorders on cognitive function and cognitive impairment in the elderly, and tries to explain the underlying mechanism of this effect from the perspective of related disease, cerebral circuit, and molecular biology.

Nanowired Delivery of Cerebrolysin Together with Antibodies to Amyloid Beta Peptide, Phosphorylated Tau, and Tumor Necrosis Factor Alpha Induces Superior Neuroprotection in Alzheimer's Disease Brain Pathology Exacerbated by Sleep Deprivation

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AβP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AβP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.