Search Results (34)

Background and Objectives: Methamphetamine (METH) is a potent psychostimulant known to induce neurotoxicity and neurodegeneration, leading to cognitive impairment. This study aimed to explore cubebin’s potential neuroprotective effects against METH-induced cognitive deficits by investigating its ability to suppress lipid peroxidation and pro-inflammatory markers and modulate neurotransmitter levels. Material and Methods: A total of 30 rats were taken and randomly grouped into five groups: group I—control; group II—METH 100 mg/kg/i.p.; group III—METH + cubebin (10 mg/kg/p.o.); group IV—METH + cubebin (20 mg/kg/p.o.); and group V—cubebin per os at 20 mg/kg. After a 14-day oral regimen, behavioral activities were assessed utilizing the Morris water maze (MWM). Biochemical analysis included neurotransmitters, including dopamine (DA), norepinephrine (NE), and gamma-aminobutyric acid (GABA); oxidative stress markers (malondialdehyde (MDA); nitric oxide (NO), catalase (CAT), reduced glutathione (GSH)); inflammatory cytokines [interleukin (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)]; neurotrophic factors (BDNF, CREB); and apoptotic markers (caspase-3 and caspase-9). Furthermore, molecular docking and simulation studies were conducted. Results: Treatment with cubebin led to a marked reduction in latency during the MWM task. It significantly modulated the oxidative stress markers (SOD, GSH, CAT, MDA, and NO), inflammatory cytokines (IL-6, IL-1β, TNF-α), neurotrophic factors (CREB, BDNF), apoptotic markers (NFkB, caspase-3, caspase-9), and neurotransmitters (NE, DA, and GABA) in METH-induced memory-impaired rats. The results of molecular dynamics simulation (MDS) provided insight into the mechanisms that associate proteins CREB, BDNF, and caspase-3 in conformational dynamics upon binding to cubebin. Conclusions: In conclusion, cubebin administration improved cognitive function in rats by modulating antioxidant enzyme activity, reducing pro-inflammatory cytokines, and regulating neurotransmitter levels, demonstrating its potential neuroprotective effects against MA-induced neurodegeneration. Full article

Schizophrenia, depression, and bipolar disorder may represent neurodegenerative conditions involving both degeneration and aberrant regeneration of monoaminergic axons. Negative and cognitive symptoms could arise from monoaminergic axon degeneration, whereas positive symptoms and manic states might result from excessive axonal regeneration and sprouting. The molecular mechanisms driving these opposing processes remain largely unclear. This review considers the possible role of calcium-independent phospholipase A₂ (iPLA2) in regulating monoamine axon degeneration and hyper-regeneration in schizophrenia. Emerging evidence suggests that pro-inflammatory signaling mediated by cytosolic PLA₂ (cPLA2) may promote monoamine axon degeneration, while anti-inflammatory iPLA2 activity could facilitate regeneration and sprouting. Overactivation of iPLA2 might lead to aberrant axonal sprouting, potentially contributing to positive symptoms through hyperdopaminergic states in the medial prefrontal cortex (mPFC). Conversely, axon degeneration in the same region may underlie negative and cognitive symptoms. The review also discusses a potential interplay between dopamine and N-methyl-D-aspartate (NMDA) receptor signaling in distinct neuronal populations of the mPFC and suggests that targeting iPLA2 and its pathways could represent a promising therapeutic strategy. Viewing schizophrenia and related disorders through the lens of monoamine axon pathology may eventually improve diagnostic precision and inform the development of treatments aimed at restoring the balance between degeneration and regeneration. Full article

Background: Robust evidence supports the role of tetrahydrobiopterin (BH4) metabolism in sustaining inflammation; however, the mechanisms underlying the persistent upregulation of the BH4 pathway remain incompletely understood. This study investigated the epigenetic regulation of BH4 metabolism following a single injection of lipopolysaccharide (LPS) in the mouse hippocampus. Methods: Male C57BL/6J mice received either saline or LPS (0.33 mg/kg, i.p.) and were sacrificed at 4 h or 24 h post injection. Behavioral assessments and analyses of hippocampal neurotransmitter metabolism, DNA methylation profile, oxidative stress, and inflammasome activation were performed. Neopterin levels, a marker of immune system activation, were measured in both the plasma and hippocampus. Results: LPS-treated mice exhibited sickness behavior, including reduced locomotor and exploratory activity at both 4 and 24 h. While exploratory behavior showed partial recovery by 24 h, locomotor activity remained impaired. Neopterin levels increased in both the plasma and hippocampus following LPS administration but returned to baseline in the hippocampus by 24 h. Despite the normalization of neopterin, a persistent pro-inflammatory state in the hippocampus was evident at 24 h, as shown by increased expression of Ikbkb and components of the NLRP3 inflammasome, along with elevated oxidative stress markers. Upregulation of Nrf-2 and Hmox1 suggested activation of a protective antioxidant response. Dopaminergic metabolism was disrupted, indicating impaired BH4-dependent dopamine turnover. Epigenetic analysis revealed increased expression of DNA methyltransferases (Dnmt1, Dnmt3a, Dnmt3b) and Tet2, along with reduced expression of Tet1 and Tet3. Promoter hypomethylation of Gch1 and Ptps was observed, correlating with increased hippocampal expression and potentially elevated BH4 levels. Conclusions: Together, these findings show that a single LPS challenge was sufficient to induce the activation of the BH4 synthesis pathway during the late acute inflammatory phase, both systemically and in the hippocampus, potentially driven by epigenetic modifications such as promoter hypomethylation. This may contribute to the perpetuation of neuroinflammation. Full article

Schizophrenia is a complex psychiatric disorder traditionally linked to neurotransmitter dysregulation, particularly within dopamine and glutamate pathways. However, recent evidence implicates the gut–brain axis as a potential contributor to its pathophysiology. This perspective article proposes a systems-level understanding of schizophrenia that incorporates the role of gut microbial dysbiosis specifically, reductions in short-chain fatty acid (SCFA)-producing taxa, and elevations in pro-inflammatory microbes. These imbalances may compromise gut barrier integrity, stimulate systemic inflammation, and disrupt neurochemical signaling in the brain. We synthesize findings from animal models, clinical cohorts, and microbial intervention trials, highlighting mechanisms such as SCFA regulation, altered tryptophan–kynurenine metabolism, and microbial impacts on neurotransmitters. We also explore microbiome-targeted interventions like probiotics, prebiotics, dietary strategies, and fecal microbiota transplantation (FMT) and their potential as adjunctive therapies. While challenges remain in causality and translation, integrating gut–brain axis insights may support more personalized and biologically informed models of schizophrenia care. Full article

Traumatic brain injury (TBI) leads to persistent pro-inflammatory microglial activation implicated in neurodegeneration. Idebenone, a coenzyme Q10 analogue that interacts with both mitochondria and the tyrosine kinase adaptor SHC1, inhibits aspects of microglial activation in vitro. We used the NanoString Neuropathology Panel to test the hypothesis that idebenone post-treatment mitigates TBI-pathology-associated acute gene expression changes by moderating the pro-inflammatory microglial response to injury. Controlled cortical impact to adult male mice increased the microglial activation signature in the peri-lesional cortex at 24 h post-TBI. Unexpectedly, several microglial signature genes upregulated by TBI were further increased by post-injury idebenone administration. However, idebenone significantly attenuated TBI-mediated perturbations to gene expression associated with behavior, particularly in the gene ontology–biological process (GO:BP) pathways “ephrin receptor signaling” and “dopamine metabolic process”. Gene co-expression analysis correlated levels of microglial complement component 1q (C1q) and the neurotrophin receptor gene Ntrk1 to large (>3-fold) TBI-induced decreases in dopamine receptor genes Drd1 and Drd2 that were mitigated by idebenone treatment. Bioinformatics analysis identified SUZ12 as a candidate transcriptional regulator of idebenone-modified gene expression changes. Overall, the results suggest that idebenone may enhance TBI-induced microglial number within the first 24 h of TBI and identify ephrin-A and dopamine signaling as novel idebenone targets. Full article

Bisphenol A (BPA) is a widespread environmental endocrine disruptor with significant neurodevelopmental and behavioral risks. The present study explored the role of the circadian clock protein NR1D1 in mediating BPA-induced anxiety-like behavior and brain inflammation early in life. Zebrafish embryos exposed to BPA exhibited anxiety-like behavior characterized by altered motor activity patterns. Notably, BPA exposure suppressed the expression of the circadian clock gene nr1d1, accompanied by increased transcriptional and protein levels of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α. These changes created a pro-inflammatory microenvironment that disrupted dopamine system homeostasis, contributing to the observed behavioral abnormalities. Activation of NR1D1 using GSK effectively reversed BPA-induced inflammatory responses and restored normal dopamine levels and behavioral phenotypes. These findings highlight NR1D1 as a critical regulator linking circadian rhythm disruption, neuroinflammation, and dopaminergic dysfunction to anxiety-like behavior. This study provides novel insights into the mechanisms underlying BPA-induced neurotoxicity and identifies NR1D1 as a potential therapeutic target for mitigating the adverse effects of early-life BPA exposure. Full article

The accumulation of misfolded and aggregated α-synuclein can trigger endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), leading to apoptotic cell death in patients with Parkinson’s disease (PD). As the major ER chaperone, glucose-regulated protein 78 (GRP78/BiP/HSPA5) plays a key role in UPR regulation. GRP78 overexpression can modulate the UPR, block apoptosis, and promote the survival of nigral dopamine neurons in a rat model of α-synuclein pathology. Here, we explore the therapeutic potential of intranasal exogenous GRP78 for preventing or slowing PD-like neurodegeneration in a lactacystin-induced rat model. We show that intranasally-administered GRP78 rapidly enters the substantia nigra pars compacta (SNpc) and other afflicted brain regions. It is then internalized by neurons and microglia, preventing the development of the neurodegenerative process in the nigrostriatal system. Lactacystin-induced disturbances, such as the abnormal accumulation of phosphorylated pS129-α-synuclein and activation of the pro-apoptotic GRP78/PERK/eIF2α/CHOP/caspase-3,9 signaling pathway of the UPR, are substantially reversed upon GRP78 administration. Moreover, exogenous GRP78 inhibits both microglia activation and the production of proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), via the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in model animals. The neuroprotective and anti-inflammatory potential of exogenous GRP78 may inform the development of effective therapeutic agents for PD and other synucleinopathies. Full article

Alcohol use disorders (AUDs) frequently co-occur with negative mood disorders, such as anxiety and depression, exacerbating relapse through dopaminergic dysfunction. Stress-related neuropeptides play a crucial role in AUD pathophysiology by modulating dopamine (DA) function. The rostromedial tegmental nucleus (RMTg), which inhibits midbrain dopamine neurons and signals aversion, has been shown to increase ethanol consumption and negative emotional states during abstinence. Despite some stress-related neuropeptides acting through the RMTg to affect addiction behaviors, their specific roles in alcohol-induced contexts remain underexplored. This study utilized an intermittent voluntary drinking model in mice to induce negative effect behavior 24 h into ethanol (EtOH) abstinence (post-EtOH). It examined changes in pro-stress (Pnoc, Oxt, Npy) and anti-stress (Crf, Pomc, Avp, Orx, Pdyn) neuropeptide-coding genes and analyzed their correlations with aversive behaviors. We observed that adult male C57BL/6J mice displayed evident anxiety, anhedonia, and depression-like symptoms at 24 h post-EtOH. The laser-capture microdissection technique, coupled with or without retrograde tracing, was used to harvest total ventral tegmental area (VTA)-projecting neurons or the intact RMTg area. The findings revealed that post-EtOH consistently reduced Pnoc and Orx levels while elevating Crf levels in these neuronal populations. Notably, RMTg Pnoc and Npy levels counteracted ethanol consumption and depression severity, while Crf levels were indicative of the mice’s anxiety levels. Together, these results underscore the potential role of stress-related neuropeptides in the RMTg in regulating the negative emotions related to AUDs, offering novel insights for future research. Full article

Parkinson’s disease is an idiopathic neurodegenerative disorder which is characterized by the degeneration of the neurons of substantia nigra, a part of the midbrain, regulating motor movement. It involves a decrease in the levels of dopamine which consequently hampers movement control. In the literature, natural compounds like flavonoids have been cited to exhibit their potential to terminate the augmentation of such a disorder by penetrating the blood–brain barrier. In this study, 10 phytoconstituents were screened using molecular docking against the dopamine D3 receptor to identify potential inhibitors. The PDB database was employed to extract the target protein of interest, i.e., the dopamine D3 receptor (PDB ID: 3PBL). Both the test drugs and the standard moiety were obtained in their 3D conformation from the PubChem in SDF format, while FlexX software was used for docking purposes. The docking scores of the selected photochemical were hence compared with Levodopa, which was taken as the positive control. The docking studies revealed that Vasicol has the closest docking score (−19.6871 kcal/mol) to that of the standard Levodopa (−23.1188 kcal/mol), proving that it has the best molecular docking result for the dopamine D3 receptor. Also, the low toxicity profile confirmed by the pro Tox-II online server indicated that Vasicol is a potential lead to be a drug candidate for treating Parkinson’s disease. Full article

Depression presents a significant global health burden, necessitating the search for effective and safe treatments. This investigation aims to assess the antidepressant effect of the hydroethanolic extract of Anacardium occidentale (AO) on depression-related behaviors in rats. The depression model involved 42 days of unpredictable chronic mild stress (UCMS) exposure and was assessed using the sucrose preference and the forced swimming (FST) test. Additionally, memory-related aspects were examined using the tests Y-maze and Morris water maze (MWM), following 21 days of treatment with varying doses of the AO extract (150, 300, and 450 mg/kg) and Imipramine (20 mg/kg), commencing on day 21. The monoamines (norepinephrine, serotonin, and dopamine), oxidative stress markers (MDA and SOD), and cytokines levels (IL-1β, IL-6, and TNF-α) within the brain were evaluated. Additionally, the concentration of blood corticosterone was measured. Treatment with AO significantly alleviated UCMS-induced and depressive-like behaviors in rats. This was evidenced by the ability of the extract to prevent further decreases in body mass, increase sucrose consumption, reduce immobility time in the test Forced Swimming, improve cognitive performance in both tests Y-maze and the Morris water maze by increasing the target quadrant dwelling time and spontaneous alternation percentage, and promote faster feeding behavior in the novelty-suppressed feeding test. It also decreased pro-inflammatory cytokines, corticosterone, and MDA levels, and increased monoamine levels and SOD activity. HPLC-MS analysis revealed the presence of triterpenoid compounds (ursolic acid, oleanolic acid, and lupane) and polyphenols (catechin quercetin and kaempferol). These results evidenced the antidepressant effects of the AO, which might involve corticosterone and monoaminergic regulation as antioxidant and anti-inflammatory activities. Full article

Cognitive impairment in schizophrenia remains a clinically and pharmacologically unsolved challenge. Clinical and preclinical studies have revealed that the concomitant reduction in dysbindin (DYS) and dopamine receptor D3 functionality improves cognitive functions. However, the molecular machinery underlying this epistatic interaction has not yet been fully elucidated. The glutamate NMDA receptors and the neurotrophin BDNF, with their established role in promoting neuroplasticity, may be involved in the complex network regulated by the D3/DYS interaction. Furthermore, as inflammation is involved in the etiopathogenesis of several psychiatric diseases, including schizophrenia, the D3/DYS interaction may affect the expression levels of pro−inflammatory cytokines. Thus, by employing mutant mice bearing selective heterozygosis for D3 and/or DYS, we provide new insights into the functional interactions (single and synergic) between these schizophrenia susceptibility genes and the expression levels of key genes for neuroplasticity and neuroinflammation in three key brain areas for schizophrenia: the prefrontal cortex, striatum, and hippocampus. In the hippocampus, the epistatic interaction between D3 and DYS reversed to the wild-type level the downregulated mRNA levels of GRIN1 and GRIN2A were observed in DYS +/− and D3 +/− mice. In all the areas investigated, double mutant mice had higher BDNF levels compared to their single heterozygote counterparts, whereas D3 hypofunction resulted in higher pro−inflammatory cytokines. These results may help to clarify the genetic mechanisms and functional interactions involved in the etiology and development of schizophrenia. Full article

Although the precise mechanisms for neurodegeneration in Parkinson’s disease (PD) are unknown, evidence suggests that neuroinflammation is a critical factor in the pathogenic process. Here, we sought to determine whether the voltage-gated proton channel, Hv1 (HVCN1), which is expressed in microglia and regulates NADPH oxidase, is associated with dopaminergic neurodegeneration. We utilized data mining to evaluate the mRNA expression of HVCN1 in the brains of PD patients and controls and uncovered increased expression of the gene encoding Hv1, HVCN1, in the brains of PD patients compared to controls, specifically in male PD patients. In an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 × 16 mg/kg) mouse model of PD, Hvcn1 gene expression was increased 2-fold in the striatum. MPTP administration to wild-type (WT) mice resulted in a ~65% loss of tyrosine hydroxylase positive neurons (TH⁺) in the substantia nigra (SN), while a ~39% loss was observed in Hv1 knockout (KO) mice. Comparable neuroprotective effects of Hv1 deficiency were found in a repeated-dose LPS model. Neuroprotection was associated with decreased pro-inflammatory cytokine levels and pro-oxidant factors in both neurotoxicant animal models. These in vivo results were confirmed in primary microglial cultures, with LPS treatment increasing Hvcn1 mRNA levels and Hv1 KO microglia failing to exhibit the LPS-mediated inflammatory response. Conditioned media from Hv1 KO microglia treated with LPS resulted in an attenuated loss of cultured dopamine neuron cell viability compared to WT microglia. Taken together, these data suggest that Hv1 is upregulated and mediates microglial pro-inflammatory cytokine production in parkinsonian models and therefore represents a novel target for neuroprotection. Full article

This case series presents the novel genetic addiction risk score (GARS), which shows a high prevalence of polymorphic risk alleles of reward genes in a nuclear family with multiple reward deficiency syndrome (RDS) behavioral issues expressing a hypodopaminergic antecedent. The family consists of a mother, father, son, and daughter. The mother experienced issues with focus, memory, anger, and amotivational syndrome. The father experienced weight issues and depression. The son experienced heavy drinking, along with some drug abuse and anxiety. The daughter experienced depression, lethargy, brain fog, focus issues, and anxiety, among others. A major clinical outcome of the results presented to the family members helped reduce personal guilt and augment potential hope for future healing. Our laboratory’s prior research established that carriers of four or more alleles measured by GARS (DRD1-DRD4, DAT1, MOR, GABABR3, COMT, MAOAA, and 5HTLPR) are predictive of the addiction severity index (ASI) for drug abuse, and carriers of seven or more alleles are predictive of severe alcoholism. This generational case series shows the impact that genetic information has on reducing stigma and guilt in a nuclear family struggling with RDS behaviors. The futuristic plan is to introduce an appropriate DNA-guided “pro-dopamine regulator” into the recovery and enhancement of life. Full article

Reward Deficiency Syndrome (RDS) is defined as a breakdown of reward neurotransmission that results in a wide range of addictive, compulsive, and impulsive behaviors. RDS is caused by a combination of environmental (epigenetic) influences and DNA-based (genetic) neurotransmission deficits that interfere with the normal satisfaction of human physiological drives (i.e., food, water, and sex). An essential feature of RDS is the lack of integration between perception, cognition, and emotions that occurs because of (1) significant dopaminergic surges in motivation, reward, and learning centers causing neuroplasticity in the striato-thalamic-frontal cortical loop; (2) hypo-functionality of the excitatory glutamatergic afferents from the amygdala–hippocampus complex. A large volume of literature regarding the known neurogenetic and psychological underpinnings of RDS has revealed a significant risk of dopaminergic gene polymorphic allele overlap between cohorts of depression and subsets of schizophrenia. The suggestion is that instead of alcohol, opioids, gambling disorders, etc. being endophenotypes, the true phenotype is RDS. Additionally, reward deficiency can result from depleted or hereditary hypodopaminergia, which can manifest as a variety of personality traits and mental/medical disorders that have been linked to genetic studies with dopamine-depleting alleles. The carrying of known DNA antecedents, including epigenetic insults, results in a life-long vulnerability to RDS conditions and addictive behaviors. Epigenetic repair of hypodopaminergia, the causative basis of addictive behaviors, may involve precision DNA-guided therapy achieved by combining the Genetic Addiction Risk Severity (GARS) test with a researched neutraceutical having a number of variant names, including KB220Z. This nutraceutical formulation with pro-dopamine regulatory capabilities has been studied and published in peer-reviewed journals, mostly from our laboratory. Finally, it is our opinion that RDS should be given an ICD code and deserves to be included in the DSM-VI because while the DSM features symptomology, it is equally important to feature etiological roots as portrayed in the RDS model. Full article

Primary cilia help to maintain cellular homeostasis by sensing conditions in the extracellular environment, including growth factors, nutrients, and hormones that are involved in various signaling pathways. Recently, we have shown that enhanced primary ciliogenesis in dopamine neurons promotes neuronal survival in a Parkinson’s disease model. Moreover, we performed fecal metabolite screening in order to identify several candidates for improving primary ciliogenesis, including L-carnitine and acetyl-L-carnitine. However, the role of carnitine in primary ciliogenesis has remained unclear. In addition, the relationship between primary cilia and neurodegenerative diseases has remained unclear. In this study, we have evaluated the effects of carnitine on primary ciliogenesis in 1-methyl-4-phenylpyridinium ion (MPP⁺)-treated cells. We found that both L-carnitine and acetyl-L-carnitine promoted primary ciliogenesis in SH-SY5Y cells. In addition, the enhancement of ciliogenesis by carnitine suppressed MPP⁺-induced mitochondrial reactive oxygen species overproduction and mitochondrial fragmentation in SH-SY5Y cells. Moreover, carnitine inhibited the production of pro-inflammatory cytokines in MPP⁺-treated SH-SY5Y cells. Taken together, our findings suggest that enhanced ciliogenesis regulates MPP⁺-induced neurotoxicity and inflammation. Full article