Displaying publications 61 - 80 of 115 in total

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  1. Ogawa S, Nathan FM, Parhar IS
    Proc Natl Acad Sci U S A, 2014 Mar 11;111(10):3841-6.
    PMID: 24567386 DOI: 10.1073/pnas.1314184111
    Kisspeptin, a neuropeptide encoded by the KISS1/Kiss1, and its cognate G protein-coupled receptor, GPR54 (kisspeptin receptor, Kiss-R), are critical for the control of reproduction in vertebrates. We have previously identified two kisspeptin genes (kiss1 and kiss2) in the zebrafish, of which kiss1 neurons are located in the habenula, which project to the median raphe. kiss2 neurons are located in the hypothalamic nucleus and send axonal projections to gonadotropin-releasing hormone neurons and regulate reproductive functions. However, the physiological significance of the Kiss1 expressed in the habenula remains unknown. Here we demonstrate the role of habenular Kiss1 in alarm substance (AS)-induced fear response in the zebrafish. We found that AS-evoked fear experience significantly reduces kiss1 and serotonin-related genes (plasmacytoma expressed transcript 1 and solute carrier family 6, member 4) in the zebrafish. Furthermore, Kiss1 administration suppressed the AS-evoked fear response. To further evaluate the role of Kiss1 in fear response, zebrafish Kiss1 peptide was conjugated to saporin (SAP) to selectively inactivate Kiss-R1-expressing neurons. The Kiss1-SAP injection significantly reduced Kiss1 immunoreactivity and c-fos mRNA in the habenula and the raphe compared with control. Furthermore, 3 d after Kiss1-SAP injection, the fish had a significantly reduced AS-evoked fear response. These findings provide an insight into the role of the habenular kisspeptin system in inhibiting fear.
    Matched MeSH terms: Neurons/metabolism
  2. Ismail N, Ismail M, Azmi NH, Abu Bakar MF, Basri H, Abdullah MA
    Oxid Med Cell Longev, 2016;2016:2528935.
    PMID: 26823946 DOI: 10.1155/2016/2528935
    Nigella sativa Linn. (N. sativa) and its bioactive constituent Thymoquinone (TQ) have demonstrated numerous pharmacological attributes. In the present study, the neuroprotective properties of Thymoquinone-rich fraction (TQRF) and TQ against hydrogen peroxide- (H2O2-) induced neurotoxicity in differentiated human SH-SY5Y cells were investigated. TQRF was extracted using supercritical fluid extraction while TQ was acquired commercially, and their effects on H2O2 were evaluated using cell viability assay, reactive oxygen species (ROS) assay, morphological observation, and multiplex gene expression. Both TQRF and TQ protected the cells against H2O2 by preserving the mitochondrial metabolic enzymes, reducing intracellular ROS levels, preserving morphological architecture, and modulating the expression of genes related to antioxidants (SOD1, SOD2, and catalase) and signaling genes (p53, AKT1, ERK1/2, p38 MAPK, JNK, and NF-κβ). In conclusion, the enhanced efficacy of TQRF over TQ was likely due to the synergism of multiple constituents in TQRF. The efficacy of TQRF was better than that of TQ alone when equal concentrations of TQ in TQRF were compared. In addition, TQRF also showed comparable effects to TQ when the same concentrations were tested. These findings provide further support for the use of TQRF as an alternative to combat oxidative stress insults in neurodegenerative diseases.
    Matched MeSH terms: Neurons/metabolism*
  3. Nouri F, Salehinejad P, Nematollahi-Mahani SN, Kamarul T, Zarrindast MR, Sharifi AM
    Cell Mol Neurobiol, 2016 Jul;36(5):689-700.
    PMID: 26242172 DOI: 10.1007/s10571-015-0249-8
    Transplantation of neural-like cells is considered as a promising therapeutic strategy developed for neurodegenerative disease in particular for ischemic stroke. Since cell survival is a major concern following cell implantation, a number of studies have underlined the protective effects of preconditioning with hypoxia or hypoxia mimetic pharmacological agents such as deferoxamine (DFO), induced by activation of hypoxia inducible factor-1 (HIF-1) and its target genes. The present study has investigated the effects of DFO preconditioning on some factors involved in cell survival, angiogenesis, and neurogenesis of neural-like cells derived from human Wharton's jelly mesenchymal stem cells (HWJ-MSCs) in presence of hydrogen peroxide (H2O2). HWJ-MSCs were differentiated toward neural-like cells for 14 days and neural cell markers were identified using immunocytochemistry. HWJ-MSC-derived neural-like cells were then treated with 100 µM DFO, as a known hypoxia mimetic agent for 48 h. mRNA and protein expression of HIF-1 target genes including brain-derived neurotrophic factors (BDNF) and vascular endothelial growth factor (VEGF) significantly increased using RT-PCR and Western blotting which were reversed by HIF-1α inhibitor, while, gene expression of Akt-1, Bcl-2, and Bax did not change significantly but pAkt-1 was up-regulated as compared to poor DFO group. However, addition of H2O2 to DFO-treated cells resulted in higher resistance to H2O2-induced cell death. Western blotting analysis also showed significant up-regulation of HIF-1α, BDNF, VEGF, and pAkt-1, and decrease of Bax/Bcl-2 ratio as compared to poor DFO. These results may suggest that DFO preconditioning of HWJ-MSC-derived neural-like cells improves their tolerance and therapeutic potential and might be considered as a valuable strategy to improve cell therapy.
    Matched MeSH terms: Neurons/metabolism
  4. Yu W, Xiao Y, Jayaraman A, Yen YC, Lee HU, Pettersson S, et al.
    EMBO Mol Med, 2025 Feb;17(2):249-264.
    PMID: 39910348 DOI: 10.1038/s44321-024-00179-y
    Changes in gut microbiota composition have been linked to anxiety behavior in rodents. However, the underlying neural circuitry linking microbiota and their metabolites to anxiety behavior remains unknown. Using male C57BL/6J germ-free (GF) mice, not exposed to live microbes, increased anxiety-related behavior was observed correlating with a significant increase in the immediate early c-Fos gene in the basolateral amygdala (BLA). This phenomenon coincided with increased intrinsic excitability and spontaneous synaptic activity of BLA pyramidal neurons associated with reduced small conductance calcium-activated potassium (SK) channel currents. Importantly, colonizing GF mice to live microbes or the microbial-derived metabolite indoles reverted SK channel activities in BLA pyramidal neurons and reduced the anxiety behavioral phenotype. These results are consistent with a molecular mechanism by which microbes and or microbial-derived indoles, regulate functional changes in the BLA neurons. Moreover, this microbe metabolite regulation of anxiety links these results to ancient evolutionarily conserved defense mechanisms associated with anxiety-related behaviors in mammals.
    Matched MeSH terms: Neurons/metabolism
  5. Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium. Electronic address: andrew.mcintosh@ed.ac.uk, Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium
    Cell, 2025 Feb 06;188(3):640-652.e9.
    PMID: 39814019 DOI: 10.1016/j.cell.2024.12.002
    In a genome-wide association study (GWAS) meta-analysis of 688,808 individuals with major depression (MD) and 4,364,225 controls from 29 countries across diverse and admixed ancestries, we identify 697 associations at 635 loci, 293 of which are novel. Using fine-mapping and functional tools, we find 308 high-confidence gene associations and enrichment of postsynaptic density and receptor clustering. A neural cell-type enrichment analysis utilizing single-cell data implicates excitatory, inhibitory, and medium spiny neurons and the involvement of amygdala neurons in both mouse and human single-cell analyses. The associations are enriched for antidepressant targets and provide potential repurposing opportunities. Polygenic scores trained using European or multi-ancestry data predicted MD status across all ancestries, explaining up to 5.8% of MD liability variance in Europeans. These findings advance our global understanding of MD and reveal biological targets that may be used to target and develop pharmacotherapies addressing the unmet need for effective treatment.
    Matched MeSH terms: Neurons/metabolism
  6. Yang C, Li X, Li Q, Zhang B, Li H, Lin J
    Neuroreport, 2017 Dec 06;28(17):1180-1185.
    PMID: 28953094 DOI: 10.1097/WNR.0000000000000903
    Chicken embryos are used widely in the fields of developmental biology and neurobiology. The chicken embryo also serves as a model to analyze gene expression and function using in ovo electroporation. Plasmids may be injected into the spinal cord or tectum of the chicken central nervous system by microinjection for electroporation. Here, we developed a novel method that combines in ovo electroporation and neuronal culturing to study gene function in the chicken tectum during embryo development. Our method can be used to study in-vivo and in-vitro exogenous genes' function. In addition, live cell imaging microscopy, immunostaining, and transfection can be used with our method to study neuronal growth, development, neurite growth and retraction, and axonal pathfinding. Our result showed that axons were present in isolated neurons after culturing for 24 h, and cell debris was low after replacing the media at 48 h. Many GFP-expressing neurons were observed in the cultured cells after 48 h. We successfully cultured the neurons for 3 weeks. Together, this method combines in ovo electroporation and neuronal culturing advantages and is more convenient for the gene function analysis.
    Matched MeSH terms: Neurons/metabolism*
  7. Damodaran T, Tan BWL, Liao P, Ramanathan S, Lim GK, Hassan Z
    J Ethnopharmacol, 2018 Oct 05;224:381-390.
    PMID: 29920356 DOI: 10.1016/j.jep.2018.06.020
    ETHNOPHARMACOLOGICAL RELEVANCE: Clitoria ternatea L. (CT), commonly known as Butterfly pea, is used in Indian Ayurvedic medicine to promote brain function and treat mental disorders. Root of CT has been proven to enhance memory, but its role in an animal model of chronic cerebral hypoperfusion (CCH), which has been considered as a major cause of brain disorders, has yet to be explored.

    AIM OF THE STUDY: To assess the motor and cognitive effects of acute oral administration of CT root methanolic extract and hippocampal long-term plasticity in the CA1 region of the CCH rat model.

    MATERIALS AND METHODS: Male Sprague Dawley rats (200-300 g) were subjected to permanent bilateral occlusion of common carotid arteries (PBOCCA) or sham operation. Then, these rats were given oral administration of CT root extract at doses of 100, 200 or 300 mg/kg on day 28 post-surgery and tested using behavioural tests (open-field test, passive avoidance task, and Morris water maze) and electrophysiological recordings (under urethane anaesthesia).

    RESULTS: Treatment with CT root extract at the doses of 200 and 300 mg/kg resulted in a significant enhancement in memory performance in CCH rats induced by PBOCCA. Furthermore, CCH resulted in inhibition of long-term potentiation (LTP) formation in the hippocampus, and CT root extract rescued the LTP impairment. The CT root extract was confirmed to improve the glutamate-induced calcium increase via calcium imaging using primary cultured rat neurons. No significance difference was found in the CaMKII expression. These results demonstrated that CT root extract ameliorates synaptic function, which may contribute to its improving effect on cognitive behaviour.

    CONCLUSIONS: Our findings demonstrated an improving effect of CT root extract on memory in the CCH rat model suggesting that CT root extract could be a potential therapeutic strategy to prevent the progression of cognitive deterioration in vascular dementia (VaD) and Alzheimer's disease (AD) patients.

    Matched MeSH terms: Neurons/metabolism
  8. Pang KL, Chin KY
    Nutrients, 2018 May 06;10(5).
    PMID: 29734791 DOI: 10.3390/nu10050570
    Oleocanthal is a minor constituent of olive oil with strong anti-inflammatory activities. Since the pathogenesis of many chronic diseases involves inflammatory and oxidative components, oleocanthal is a promising agent to prevent these conditions. This review aimed to summarise the current beneficial health effects of oleocanthal and the molecular basis of its biological actions. The anti-inflammatory, antioxidative, antimicrobial, anticancer and neuroprotective activities of oleocanthal have been examined by previous studies. Of these, studies on the anticancer effects have been the most extensive. Oleocanthal was reported to suppress melanoma, breast, liver, and colon cancer cells. Neurological studies focused on the effects of oleocanthal against Alzheimer’s disease. Oleocanthal improved clearance of the amyloid beta protein from neurons and reduced the inflammation of astrocytes. Despite the positive results, validation of the biological effects of oleocanthal in animal disease models is limited and should be emphasized in the future. As a conclusion, oleocanthal may act together with other bioactive compounds in olive oil to achieve its therapeutic potential. The use of oleocanthal alone as a single therapeutic measure awaits validation from future studies.
    Matched MeSH terms: Neurons/metabolism
  9. Othman FN, Muthuraju S, Noor SSM, Abdullah S, Mohd Yusoff AA, Tharakan J, et al.
    Tuberculosis (Edinb), 2018 09;112:45-51.
    PMID: 30205968 DOI: 10.1016/j.tube.2018.07.007
    The present study aimed to investigate the involvement of the angiogenic marker vascular endothelia growth factor (VEGF) and apoptotic markers of Bcl-2 and Bax in the neurons and astrocytes in the brain infected by Mycobacterium tuberculosis. The immunohistochemistry staining was performed to analyze the expression of the VEGF, Bcl-2 and Bax in the astrocytes and neurons. The expression of VEGF was high in neurons and astrocytes in both the infected brain and control tissues with no difference of angiogenic activity (p = 0.40). Higher Bcl-2 expression was seen in astrocytes of infected brain tissues compared to the control tissues (p = 0.004) promoted a higher anti-apoptotic activity in astrocytes. The neurons expressed strong Bax expression in the infected brain tissues compared to the control tissues (p 
    Matched MeSH terms: Neurons/metabolism*
  10. Gan SY, Wong LZ, Wong JW, Tan EL
    Int J Biol Macromol, 2019 Jan;121:207-213.
    PMID: 30300695 DOI: 10.1016/j.ijbiomac.2018.10.021
    Alzheimer's disease (AD) is a neurodegenerative disease that leads to progressive loss of neurons which often results in deterioration of memory and cognitive function. The development of AD is highly associated with the formation of senile plaques and neurofibrillary tangles. Amyloid β (Aβ) induces neurotoxicity and contributes to the development of AD. Recent evidences also highlighted the importance of neuroglobin (Ngb) in ameliorating AD. This study assessed the ability of fucosterol, a phytosterol found in brown alga, in protecting SH-SY5Y cells against Aβ-induced neurotoxicity. Its effects on the mRNA levels of APP and Ngb as well as the intracellular Aβ levels were also determined in Aβ-induced SH-SY5Y cells. SH-SY5Y cells were exposed to fucosterol prior to Aβ treatment. The effect on apoptosis was determined using Annexin V FITC staining and mRNA expression was studied using RT-PCR. Flow cytometry confirmed the protective effects of fucosterol on SH-SY5Y cells against Aβ-induced apoptosis. Pretreatment with fucosterol increased the Ngb mRNA levels but reduced the levels of APP mRNA and intracellular Aβ in Aβ-induced SH-SY5Y cells. These observations demonstrated the protective properties of fucosterol against Aβ-induced neurotoxicity in neuronal cells.
    Matched MeSH terms: Neurons/metabolism
  11. Abd Aziz CB, Ahmad Suhaimi SQ, Hasim H, Ahmad AH, Long I, Zakaria R
    J Integr Med, 2019 Jan;17(1):66-70.
    PMID: 30591413 DOI: 10.1016/j.joim.2018.12.002
    OBJECTIVE: This study was done to determine whether Tualang honey could prevent the altered nociceptive behaviour, with its associated changes of oxidative stress markers and morphology of the spinal cord, among the offspring of prenatally stressed rats.

    METHODS: Pregnant rats were divided into three groups: control, stress, and stress treated with Tualang honey. The stress and stress treated with Tualang honey groups were subjected to restraint stress from day 11 of pregnancy until delivery. Ten week old male offspring (n = 9 from each group) were given formalin injection and their nociceptive behaviours were recorded. After 2 h, the rats were sacrificed, and their spinal cords were removed to assess oxidative stress activity and morphology. Nociceptive behaviour was analysed using repeated measures analysis of variance (ANOVA), while the levels of oxidative stress parameters and number of Nissl-stained neurons were analysed using a one-way ANOVA.

    RESULTS: This study demonstrated that prenatal stress was associated with increased nociceptive behaviour, changes in the oxidative stress parameters and morphology of the spinal cord of offspring exposed to prenatal stress; administration of Tualang honey reduced the alteration of these parameters.

    CONCLUSION: This study provides a preliminary understanding of the beneficial effects of Tualang honey against the changes in oxidative stress and neuronal damage in the spinal cord of the offspring of prenatally stressed rats.

    Matched MeSH terms: Neurons/metabolism
  12. Meyer K, Feldman HM, Lu T, Drake D, Lim ET, Ling KH, et al.
    Cell Rep, 2019 01 29;26(5):1112-1127.e9.
    PMID: 30699343 DOI: 10.1016/j.celrep.2019.01.023
    The molecular basis of the earliest neuronal changes that lead to Alzheimer's disease (AD) is unclear. Here, we analyze neural cells derived from sporadic AD (SAD), APOE4 gene-edited and control induced pluripotent stem cells (iPSCs). We observe major differences in iPSC-derived neural progenitor (NP) cells and neurons in gene networks related to neuronal differentiation, neurogenesis, and synaptic transmission. The iPSC-derived neural cells from SAD patients exhibit accelerated neural differentiation and reduced progenitor cell renewal. Moreover, a similar phenotype appears in NP cells and cerebral organoids derived from APOE4 iPSCs. Impaired function of the transcriptional repressor REST is strongly implicated in the altered transcriptome and differentiation state. SAD and APOE4 expression result in reduced REST nuclear translocation and chromatin binding, and disruption of the nuclear lamina. Thus, dysregulation of neural gene networks may set in motion the pathologic cascade that leads to AD.
    Matched MeSH terms: Neurons/metabolism*
  13. Simon C, Gan QF, Kathivaloo P, Mohamad NA, Dhamodharan J, Krishnan A, et al.
    Int J Mol Sci, 2019 Jan 29;20(3).
    PMID: 30699944 DOI: 10.3390/ijms20030568
    Parkinson's disease (PD) is a neurodegenerative disorder defined by progressive deterioration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Dental pulp stem cells (DPSCs) have been proposed to replace the degenerated dopaminergic neurons due to its inherent neurogenic and regenerative potential. However, the effective delivery and homing of DPSCs within the lesioned brain has been one of the many obstacles faced in cell-based therapy of neurodegenerative disorders. We hypothesized that DPSCs, delivered intranasally, could circumvent these challenges. In the present study, we investigated the therapeutic efficacy of intranasally administered DPSCs in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. Human deciduous DPSCs were cultured, pre-labelled with PKH 26, and intranasally delivered into PD mice following MPTP treatment. Behavioural analyses were performed to measure olfactory function and sensorimotor coordination, while tyrosine hydroxylase (TH) immunofluorescence was used to evaluate MPTP neurotoxicity in SNpc neurons. Upon intranasal delivery, degenerated TH-positive neurons were ameliorated, while deterioration in behavioural performances was significantly enhanced. Thus, the intranasal approach enriched cell delivery to the brain, optimizing its therapeutic potential through its efficacious delivery and protection against dopaminergic neuron degeneration.
    Matched MeSH terms: Dopaminergic Neurons/metabolism
  14. Tey S, Shahrizaila N, Drew AP, Samulong S, Goh KJ, Battaloglu E, et al.
    Neurogenetics, 2019 08;20(3):117-127.
    PMID: 31011849 DOI: 10.1007/s10048-019-00576-3
    Charcot-Marie-Tooth (CMT) disease is a form of inherited peripheral neuropathy that affects motor and sensory neurons. To identify the causative gene in a consanguineous family with autosomal recessive CMT (AR-CMT), we employed a combination of linkage analysis and whole exome sequencing. After excluding known AR-CMT genes, genome-wide linkage analysis mapped the disease locus to a 7.48-Mb interval on chromosome 14q32.11-q32.33, flanked by the markers rs2124843 and rs4983409. Whole exome sequencing identified two non-synonymous variants (p.T40P and p.H915Y) in the AHNAK2 gene that segregated with the disease in the family. Pathogenic predictions indicated that p.T40P is the likely causative allele. Analysis of AHNAK2 expression in the AR-CMT patient fibroblasts showed significantly reduced mRNA and protein levels. AHNAK2 binds directly to periaxin which is encoded by the PRX gene, and PRX mutations are associated with another form of AR-CMT (CMT4F). The altered expression of mutant AHNAK2 may disrupt the AHNAK2-PRX interaction in which one of its known functions is to regulate myelination.
    Matched MeSH terms: Neurons/metabolism
  15. Jaafaru MS, Nordin N, Rosli R, Shaari K, Bako HY, Noor NM, et al.
    Biomed Pharmacother, 2019 Nov;119:109445.
    PMID: 31541852 DOI: 10.1016/j.biopha.2019.109445
    The antioxidant and neuroprotective activity of Glucomoringin isothiocyanate (GMG-ITC) have been reported in in vivo and in vitro models of neurodegenerative diseases. However, its neuroprotective role via mitochondrial-dependent pathway in a noxious environment remains unknown. The main objective of the present study was to unveil the mitochondrial apoptotic genes' profile and prospectively link with neuroprotective activity of GMG-ITC through its ROS scavenging. The results showed that pre-treatment of differentiated SH-SY5Y cells with 1.25 μg/mL purified isolated GMG-ITC, significantly reduced reactive oxygen species (ROS) production level, compared to H2O2 control group, as evidenced by flow cytometry-based evaluation of ROS generation. Presence of GMG-ITC prior to development of oxidative stress condition, downregulated the expression of cyt-c, p53, Apaf-1, Bax, CASP3, CASP8 and CASP9 genes with concurrent upregulation of Bcl-2 gene in mitochondrial apoptotic signalling pathway. Protein Multiplex revealed significant decreased in cyt-c, p53, Apaf-1, Bax, CASP8 and CASP9 due to GMG-ITC pre-treatment in oxidative stress condition. The present findings speculated that pre-treatment with GMG-ITC may alleviate oxidative stress condition in neuronal cells by reducing ROS production level and protect the cells against apoptosis via neurodegenerative disease potential pathways.
    Matched MeSH terms: Neurons/metabolism
  16. Venugopal C, K S, Rai KS, Pinnelli VB, Kutty BM, Dhanushkodi A
    Curr Gene Ther, 2018;18(5):307-323.
    PMID: 30209999 DOI: 10.2174/1566523218666180913152615
    INTRODUCTION: Mesenchymal Stem Cell (MSC) therapy in recent years has gained significant attention. Though the functional outcomes following MSC therapy for neurodegenerative diseases are convincing, various mechanisms for the functional recovery are being debated. Nevertheless, recent studies convincingly demonstrated that recovery following MSC therapy could be reiterated with MSC secretome per se thereby shifting the dogma from cell therapy to cell "based" therapy. In addition to various functional proteins, stem cell secretome also includes extracellular membrane vesicles like exosomes. Exosomes which are of "Nano" size have attracted significant interest as they can pass through the bloodbrain barrier far easily than macro size cells or growth factors. Exosomes act as a cargo between cells to bring about significant alterations in target cells. As the importance of exosomes is getting unveil, it is imperial to carry out a comprehensive study to evaluate the neuroprotective potential of exosomes as compared to conventional co-culture or total condition medium treatments.

    OBJECTIVE: Thus, the present study is designed to compare the neuroprotective potential of MSC derived exosomes with MSC-condition medium or neuron-MSC-co-culture system against kainic acid induced excitotoxicity in in vitro condition. The study also aims at comparing the neuroprotective efficacy of exosomes/condition medium/co-culture of two MSC viz., neural crest derived human Dental Pulp Stem Cells (hDPSC) and human Bone-Marrow Mesenchymal Stem Cells (hBM-MSC) to identify the appropriate MSC source for treating neurodegenerative diseases.

    RESULT: Our results demonstrated that neuroprotective efficacy of MSC-exosomes is as efficient as MSC-condition medium or neuron-MSC co-culture system and treating degenerating hippocampal neurons with all three MSC based approaches could up-regulate host's endogenous growth factor expressions and prevent apoptosis by activating cell survival PI3K-B-cell lymphoma-2 (Bcl-2) pathway.

    CONCLUSION: Thus, the current study highlights the possibilities of treating neurodegenerative diseases with "Nano" size exosomes as opposed to transplanting billions of stem cells which inherit several disadvantages.

    Matched MeSH terms: Neurons/metabolism*
  17. Davoudi M, Vijeepallam K, Azizi H, Mirnajafi-Zadeh J, Semnanian S
    J Neural Transm (Vienna), 2019 11;126(11):1425-1435.
    PMID: 31493096 DOI: 10.1007/s00702-019-02064-2
    The locus coeruleus (LC) as a target of addictive drugs receives a dense projection of orexinergic fibres from the lateral hypothalamus (LH) and is accordingly a candidate site for the expression of the somatic aspects of morphine withdrawal. Recently it has been shown that the inhibitory synaptic currents of LC neurons decrease partly through orexin type 1 receptors in the context of naloxone-induced morphine withdrawal; however, its cellular mechanism remains unclear. In this study, whole-cell patch clamp recordings of LC neurons in brainstem slices were used to investigate the impact of protein kinase C (PKC) on GABAergic inhibitory post-synaptic currents (IPSCs) in the context of naloxone-induced morphine withdrawal. Male Wistar rats (P14-P21) received morphine (20 mg/kg, i.p.) daily for 7 consecutive days to induce morphine dependency. Our results showed that the application of PKC inhibitor (Go 6983; 1 µM) alone did not decrease the probability of GABA release in the LC neurons of the morphine-treated rats in the presence of naloxone. Although, Go 6983 reversed the reduction of the amplitude of evoked IPSCs (eIPSCs) and spontaneous IPSCs (sIPSCs) frequency induced by orexin-A but did not change the sIPSCs amplitude. These results indicate that the suppressive effect of orexin-A on IPSCs is probably reversed by PKC inhibitor in the LC neurons of morphine-treated rats in the context of naloxone withdrawal.
    Matched MeSH terms: Neurons/metabolism
  18. Paudel YN, Angelopoulou E, Piperi C, Othman I, Shaikh MF
    Pharmacol Res, 2020 06;156:104792.
    PMID: 32278047 DOI: 10.1016/j.phrs.2020.104792
    Amyotrophic lateral sclerosis (ALS) is a devastating and rapidly progressing neurodegenerative disorder with no effective disease-modifying treatment up to date. The underlying molecular mechanisms of ALS are not yet completely understood. However, the critical role of the innate immune system and neuroinflammation in ALS pathogenesis has gained increased attention. High mobility group box 1 (HMGB1) is a typical damage-associated molecular pattern (DAMP) molecule, acting as a pro-inflammatory cytokine mainly through activation of its principal receptors, the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4) which are crucial components of the innate immune system. HMGB1 is an endogenous ligand for both RAGE and TLR4 that mediate its biological effects. Herein, on the ground of pre-clinical findings we unravel the underlying mechanisms behind the plausible contribution of HMGB1 and its receptors (RAGE and TLR4) in the ALS pathogenesis. Furthermore, we provide an account of the therapeutic outcomes associated with inhibition/blocking of HMGB1 receptor signalling in preventing motor neuron's death and delaying disease progression in ALS experimental models. There is strong evidence that HMGB1, RAGE and TLR4 signaling axes might present potential targets against ALS, opening a novel headway in ALS research that could plausibly bridge the current treatment gap.
    Matched MeSH terms: Motor Neurons/metabolism*
  19. Tan SZK, Temel Y, Chan AY, Mok ATC, Perucho JAU, Blokland A, et al.
    Brain Struct Funct, 2020 Sep;225(7):1957-1966.
    PMID: 32594260 DOI: 10.1007/s00429-020-02102-w
    Electrical stimulation of the dorsolateral periaqueductal gray (dlPAG) in rats has been shown to elicit panic-like behaviour and can be a useful as an unconditioned stimulus for modelling anticipatory fear and agoraphobia in a contextual fear conditioning paradigm. In this study, we further analysed our previous data on the effects of escitalopram (a selective serotonin reuptake inhibitor, SSRI) and buspirone (a 5-HT1A receptor partial agonist) on dlPAG-induced anticipatory fear behaviour in a rat model using freezing as a measure. We then attempted to unravel some of the interactions with dopamine signalling using tyrosine hydroxylase (TH) immunohistochemistry to probe the effects on dopaminergic neurons. We showed that acute treatment of escitalopram, but not buspirone, was effective in reducing anticipatory freezing behaviour, while chronic administrations of both drugs were effective. We found that the dlPAG stimulation induced increase number of dopaminergic neurons in the ventral tegmental area (VTA) which was reversed in both chronic buspirone and escitalopram groups. We further found a strong positive correlation between the number of dopaminergic neurons and freezing in the VTA and showed positive correlations between dopaminergic neurons in the VTA and substantia nigra pars compacta (SNpc) in escitalopram and buspirone groups, respectively. Overall, we showed that chronic treatment with an SSRI and a 5-HT1A agonist reduced anticipatory freezing behaviour which seems to be associated, through correlative studies, with a reversal of dlPAG stimulation induced increase in number of dopaminergic neurons in the VTA and/or SNpc.
    Matched MeSH terms: Dopaminergic Neurons/metabolism
  20. Teo CH, Soga T, Parhar I
    Sci Rep, 2020 08 17;10(1):13876.
    PMID: 32807874 DOI: 10.1038/s41598-020-70710-x
    Neurons synthesizing gonadotropin-inhibitory hormone (GnIH) have been implicated in the control of reproduction, food intake and stress. Serotonin (5-HT) receptors have been shown in GnIH neurons; however, their functional role in the regulation of GnIH neurons remains to be elucidated. In this study, we measured intracellular calcium ion levels following 5-HT treatment to hypothalamic primary cultures of enhanced fluorescent green protein-tagged GnIH (EGFP-GnIH) neurons from Wistar rat pups of mixed sex. Three days after initial seeding of the primary cultures, the test groups were pre-treated with lithium chloride to selectively inhibit glycogen synthase kinase 3 beta to promote intracellular calcium levels, whereas the control groups received culture medium with no lithium chloride treatment. 24 h later, the cultures were incubated with rhodamine-2AM (rhod-2AM) calcium indicator dye for one hour prior to imaging. 5-HT was added to the culture dishes 5 min after commencement of imaging. Analysis of intracellular calcium levels in EGFP-GnIH neurons showed that pre-treatment with lithium chloride before 5-HT treatment resulted in significant increase in intracellular calcium levels, two times higher than the baseline. This suggests that lithium chloride enhances the responsiveness of GnIH neurons to 5-HT.
    Matched MeSH terms: Neurons/metabolism*
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