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  1. The dopamine D1 receptor antagonist SCH-23390 blocks the acquisition, but not expression of mitragynine-induced conditioned place preference in rats
    Japarin RA, Harun N, Hassan Z, Müller CP
    Behav Brain Res, 2023 Sep 13;453:114638.
    PMID: 37619769 DOI: 10.1016/j.bbr.2023.114638
    Mitragynine (MG) is the primary active constituent of Mitragyna speciosa Korth (kratom), a psychoactive Southeast Asian plant with potential therapeutic use. Numerous studies support roles of dopaminergic system in drug reward. However, the involvement of the dopaminergic system in mediating MG reward and drug-seeking is poorly understood. Using conditioned place preference (CPP) paradigm, the present study aims to evaluate the roles of the dopamine (DA) D1 receptor in the acquisition and expression of MG-induced CPP in rats. The effects of SCH-23390, a selective DA D1 receptor antagonist, on the acquisition of MG-induced CPP were first investigated. Rats were pre-treated systemically with SCH-23390 (0, 0.1 and 0.3 mg/kg, i.p.) prior to MG (10 mg/kg) conditioning sessions. Next, we tested the effects of the DA D1 receptor antagonist on the expression of MG-induced CPP. Furthermore, the effects of a MG-priming dose (5 mg/kg) on the reinstatement of extinguished CPP were tested. The results showed that SCH-23390 dose-dependently suppressed the acquisition of a MG-induced CPP. In contrast, SCH-23390 had no effect on the expression of a MG-induced CPP. The findings of this study suggested a crucial role of the DA D1 receptor in the acquisition, but not the expression of the rewarding effects of MG in a CPP test. Furthermore, blockade of the D1-like receptor during conditioning did not prevent MG priming effects on CPP reinstatement test, suggesting no role for the DA D1 receptor in reinstatement sensitivity.
    Matched MeSH terms: Dopamine; Receptors, Dopamine D1*; Dopamine Antagonists/pharmacology
  2. The neuromodulatory role of dopamine in improved reaction time by acute cardiovascular exercise
    Ando S, Fujimoto T, Sudo M, Watanuki S, Hiraoka K, Takeda K, et al.
    J Physiol, 2024 Feb;602(3):461-484.
    PMID: 38165254 DOI: 10.1113/JP285173
    Acute cardiovascular physical exercise improves cognitive performance, as evidenced by a reduction in reaction time (RT). However, the mechanistic understanding of how this occurs is elusive and has not been rigorously investigated in humans. Here, using positron emission tomography (PET) with [11 C]raclopride, in a multi-experiment study we investigated whether acute exercise releases endogenous dopamine (DA) in the brain. We hypothesized that acute exercise augments the brain DA system, and that RT improvement is correlated with this endogenous DA release. The PET study (Experiment 1: n = 16) demonstrated that acute physical exercise released endogenous DA, and that endogenous DA release was correlated with improvements in RT of the Go/No-Go task. Thereafter, using two electrical muscle stimulation (EMS) studies (Experiments 2 and 3: n = 18 and 22 respectively), we investigated what triggers RT improvement. The EMS studies indicated that EMS with moderate arm cranking improved RT, but RT was not improved following EMS alone or EMS combined with no load arm cranking. The novel mechanistic findings from these experiments are: (1) endogenous DA appears to be an important neuromodulator for RT improvement and (2) RT is only altered when exercise is associated with central signals from higher brain centres. Our findings explain how humans rapidly alter their behaviour using neuromodulatory systems and have significant implications for promotion of cognitive health. KEY POINTS: Acute cardiovascular exercise improves cognitive performance, as evidenced by a reduction in reaction time (RT). However, the mechanistic understanding of how this occurs is elusive and has not been rigorously investigated in humans. Using the neurochemical specificity of [11 C]raclopride positron emission tomography, we demonstrated that acute supine cycling released endogenous dopamine (DA), and that this release was correlated with improved RT. Additional electrical muscle stimulation studies demonstrated that peripherally driven muscle contractions (i.e. exercise) were insufficient to improve RT. The current study suggests that endogenous DA is an important neuromodulator for RT improvement, and that RT is only altered when exercise is associated with central signals from higher brain centres.
    Matched MeSH terms: Dopamine*
  3. Parkinson's disease diagnosis using deep learning: A bibliometric analysis and literature review
    Abumalloh RA, Nilashi M, Samad S, Ahmadi H, Alghamdi A, Alrizq M, et al.
    Ageing Res Rev, 2024 Apr;96:102285.
    PMID: 38554785 DOI: 10.1016/j.arr.2024.102285
    Parkinson's Disease (PD) is a progressive neurodegenerative illness triggered by decreased dopamine secretion. Deep Learning (DL) has gained substantial attention in PD diagnosis research, with an increase in the number of published papers in this discipline. PD detection using DL has presented more promising outcomes as compared with common machine learning approaches. This article aims to conduct a bibliometric analysis and a literature review focusing on the prominent developments taking place in this area. To achieve the target of the study, we retrieved and analyzed the available research papers in the Scopus database. Following that, we conducted a bibliometric analysis to inspect the structure of keywords, authors, and countries in the surveyed studies by providing visual representations of the bibliometric data using VOSviewer software. The study also provides an in-depth review of the literature focusing on different indicators of PD, deployed approaches, and performance metrics. The outcomes indicate the firm development of PD diagnosis using DL approaches over time and a large diversity of studies worldwide. Additionally, the literature review presented a research gap in DL approaches related to incremental learning, particularly in relation to big data analysis.
    Matched MeSH terms: Dopamine
  4. Fulltext Epigenetic changes of DRD2 gene in Pathogenesis of Schizophrenia
    Nour El Huda Abd Rahim, Mohd Nabil Fikri Rahim, Norsidah Ku Zaifah, Hanisah Mohd Noor, Kartini Abdullah, Norlelawati A. Talib
    International Medical Journal Malaysia, 2017;16(11):3-3.
    MyJurnal
    The dopamine hypothesis has earlier dominated the theories for the
    development of schizophrenia based on the early pharmacologic evidence. The
    antipsychotic drugs, among others, is thought to interfere with the function of the
    dopamine D2 receptor (DRD2) resulting in clinical improvement. Accumulating evidence
    suggest the role of epigenetic mechanisms in the pathophysiology of schizophrenia.
    Despite this, specific evidence linking the DRD2 DNA methylation with schizophrenia is
    insufficient mainly due to the poor accessibility and limited brain samples. Of late, new
    data has suggested the global impact of DNA methylation in the development of
    schizophrenia, thus methylation in the peripheral blood could infer changes in the brain.
    The aim of this study was to assess the DRD2 DNA methylation in the peripheral blood of
    schizophrenia.
    Matched MeSH terms: Dopamine; Receptors, Dopamine D2
  5. Fulltext Boronate derivatives of functionally diverse catechols: stability studies
    Ketuly KA, Hadi AH
    Molecules, 2010 Apr;15(4):2347-56.
    PMID: 20428047 DOI: 10.3390/molecules15042347
    Benzeneboronate of catecholic carboxyl methyl esters, N-acetyldopamine, coumarin and catechol estrogens were prepared as crystalline derivatives in high yield. Related catechol compounds with extra polar functional group(s) (OH, NH2) do not form or only partially form unstable cyclic boronate derivatives.
    Matched MeSH terms: Dopamine/analogs & derivatives*; Dopamine/chemistry
  6. Fulltext Hematite nanoparticles-modified electrode based electrochemical sensing platform for dopamine
    Kamali KZ, Alagarsamy P, Huang NM, Ong BH, Lim HN
    ScientificWorldJournal, 2014;2014:396135.
    PMID: 25136664 DOI: 10.1155/2014/396135
    Hematite (α-Fe2O3) nanoparticles were synthesized by the solid transformation of ferrous hydroxide and ferrihydrite in hydrothermal condition. The as-prepared α-Fe2O3 nanoparticles were characterized by UV-vis, PL, XRD, Raman, TEM, AFM, FESEM, and EDX analysis. The experimental results indicated the formation of uniform hematite nanoparticles with an average size of 45 nm and perfect crystallinity. The electrochemical behavior of a GC/α-Fe2O3 electrode was studied using CV and EIS techniques with an electrochemical probe, [Fe(CN)6](3-/4-) redox couple. The electrocatalytic activity was investigated toward DA oxidation in a phosphate buffer solution (pH 6.8) by varying different experimental parameters. The chronoamperometric study showed a linear response in the range of 0-2 μM with LoD of 1.6 μM for DA. Square wave voltammetry showed a linear response in the range of 0-35 μM with LoD of 236 nM for DA.
    Matched MeSH terms: Dopamine/chemistry*
  7. Homology modeling of the human 5-HT1A, 5-HT 2A, D1, and D2 receptors: model refinement with molecular dynamics simulations and docking evaluation
    Yap BK, Buckle MJ, Doughty SW
    J Mol Model, 2012 Aug;18(8):3639-55.
    PMID: 22354276 DOI: 10.1007/s00894-012-1368-5
    5-HT(1A) serotonin and D1 dopamine receptor agonists have been postulated to be able to improve negative and cognitive impairment symptoms of schizophrenia, while partial agonists and antagonists of the D2 and 5-HT(2A) receptors have been reported to be effective in reducing positive symptoms. There is therefore a need for well-defined homology models for the design of more selective antipsychotic agents, since no three-dimensional (3D) crystal structures of these receptors are currently available. In this study, homology models were built based on the high-resolution crystal structure of the β(2)-adrenergic receptor (2RH1) and further refined via molecular dynamics simulations in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid bilayer system with the GROMOS96 53A6 united atom force field. Docking evaluations with representative agonists and antagonists using AutoDock 4.2 revealed binding modes in agreement with experimentally determined site-directed mutagenesis data and significant correlations between the computed and experimental pK (i) values. The models are also able to distinguish between antipsychotic agents with different selectivities and binding affinities for the four receptors, as well as to differentiate active compounds from decoys. Hence, these human 5-HT(1A), 5-HT(2A), D1 and D2 receptor homology models are capable of predicting the activities of novel ligands, and can be used as 3D templates for antipsychotic drug design and discovery.
    Matched MeSH terms: Dopamine/chemistry; Receptors, Dopamine D1/chemistry*; Receptors, Dopamine D2/chemistry*; Dopamine Antagonists/chemistry
  8. Fulltext Prediction of clinical symptoms of Schizophrenia based on COMT Methylation marker
    Nour El Huda Abd Rahim, Mohd Nabil Fikri Rahim, Norsidah Ku Zaifah, Hanisah Mohd Noor, Kartini Abdullah, Norlelawati A. Talib
    International Medical Journal Malaysia, 2017;16(11):19-19.
    MyJurnal
    The dopamine hypothesis of schizophrenia is based on the fact that hyperdopaminergic
    state is involved in causing psychosis and antipsychotic drugs block the
    dopamine receptor. COMT regulates the homeostatic levels of neurotransmitter
    dopamine in the synapses and plays a role in the neurocognitive function. The
    dysregulation of dopamine in the prefrontal cortex influences the cognitive function and
    the severity of the psychotic symptoms in schizophrenia. During epigenetic event,
    methylated COMT gene may cause reduction in its expression and contribute to the
    clinical presentation of schizophrenia. Therefore, the aim of this study was to assess the
    feasibility of using COMT DNA methylation for the prediction of specific psychotic
    presentation of schizophrenia. (Copied from article).
    Matched MeSH terms: Dopamine; Receptors, Dopamine
  9. Fulltext Dopa-responsive dystonia of childhood: a case report
    Tan KK, Easaw PE
    Singapore Med J, 1995 Jun;36(3):326-7.
    PMID: 8553105
    A 5-year-old Chinese boy presented with difficulty in walking and weakness of his lower limbs for one year, especially towards the evening. Bilateral equinovarus posturing of the feet and tremors of the upper limbs were noted on physical examination. Dopa-responsive dystonia was diagnosed after a remarkable symptomatic response to levodopa. This disorder is reported here to highlight an often misdiagnosed condition is children which is important because it is treatable. Dopa-responsive dystonia should be considered in the differential diagnosis of gait disturbance in children.
    Matched MeSH terms: Dopamine Agents/therapeutic use*
  10. Fulltext Understanding translational research in schizophrenia: A novel insight into animal models
    Malik JA, Yaseen Z, Thotapalli L, Ahmed S, Shaikh MF, Anwar S
    Mol Biol Rep, 2023 Apr;50(4):3767-3785.
    PMID: 36692676 DOI: 10.1007/s11033-023-08241-7
    Schizophrenia affects millions of people worldwide and is a major challenge for the scientific community. Like most psychotic diseases, it is also considered a complicated mental disorder caused by an imbalance in neurotransmitters. Due to the complexity of neuropathology, it is always a complicated disorder. The lack of proper understanding of the pathophysiology makes the disorder unmanageable in clinical settings. However, due to recent advances in animal models, we hope we can have better therapeutic approaches with more success in clinical settings. Dopamine, glutamate, GABA, and serotonin are the neurotransmitters involved in the pathophysiology of schizophrenia. Various animal models have been put forward based on these neurotransmitters, including pharmacological, neurodevelopmental, and genetic models. Polymorphism of genes such as dysbindin, DICS1, and NRG1 has also been reported in schizophrenia. Hypothesis based on dopamine, glutamate, and serotonin are considered successful models of schizophrenia on which drug therapies have been designed to date. New targets like the orexin system, muscarinic and nicotinic receptors, and cannabinoid receptors have been approached to alleviate the negative and cognitive symptoms. The non-pharmacological models like the post-weaning social isolation model (maternal deprivation), the isolation rearing model etc. have been also developed to mimic the symptoms of schizophrenia and to create and test new approaches of drug therapy which is a breakthrough at present in psychiatric disorders. Different behavioral tests have been evaluated in these specific models. This review will highlight the currently available animal models and behavioral tests in psychic disorders concerning schizophrenia.
    Matched MeSH terms: Dopamine/therapeutic use
  11. The beer component hordenine inhibits alcohol addiction-associated behaviours in mice
    Li Y, Vogel C, Kalinichenko LS, Hübner H, Weikert D, Schaefer N, et al.
    Addict Biol, 2023 Aug;28(8):e13305.
    PMID: 37500485 DOI: 10.1111/adb.13305
    Alcohol consumption is a widespread behaviour that may eventually result in the development of alcohol use disorder (AUD). Alcohol, however, is rarely consumed in pure form but in fruit- or corn-derived preparations, like beer. These preparations add other compounds to the consumption, which may critically modify alcohol intake and AUD risk. We investigated the effects of hordenine, a barley-derived beer compound on alcohol use-related behaviours. We found that the dopamine D2 receptor agonist hordenine (50 mg/kg) limited ongoing alcohol consumption and prophylactically diminished relapse drinking after withdrawal in mice. Although not having reinforcing effects on its own, hordenine blocked the establishment of alcohol-induced conditioned place preference (CPP). However, it independently enhanced alcohol CPP retrieval. Hordenine had a dose-dependent inhibitory effect on locomotor activity. Chronic hordenine exposure enhanced monoamine tissue levels in many brain regions. Further characterization revealed monoaminergic binding sites of hordenine and found a strong binding on the serotonin and dopamine transporters, and dopamine D3 , and adrenergic α1A and α2A receptor activation but no effects on GABAA receptor or glycinergic signalling. These findings suggest that natural ingredients of beer, like hordenine, may work as an inhibitory and use-regulating factor by their modulation of monoaminergic signalling in the brain.
    Matched MeSH terms: Dopamine; Dopamine Agonists
  12. Current Status and Challenges in Rotigotine Delivery
    Md S, Karim S, Saker SR, Gie OA, Hooi LC, Yee PH, et al.
    Curr Pharm Des, 2020;26(19):2222-2232.
    PMID: 32175832 DOI: 10.2174/1381612826666200316154300
    Rotigotine is a non-ergoline, high lipophilic dopamine agonist. It is indicated as the first-line therapy for Parkinson's disease (PD) and Restless Leg Syndrome (RLS). However, the precise mechanism of rotigotine is yet to be known. Rotigotine has similar safety and tolerability to the other oral non-ergolinic dopamine antagonists in clinical trials, which include nausea, dizziness and somnolence. Neupro® was the first marketed transdermal patch formulation having rotigotine. The transdermal delivery system is advantageous as it enables continuous administration of the drug, thus providing steady-state plasma drug concentration for 24-hours. Intranasal administration of rotigotine allows the drug to bypass the blood-brain barrier enabling it to reach the central nervous system within minutes. Rotigotine can also be formulated as an extended-release microsphere for injection. Some challenges remain in other routes of rotigotine administration such as oral, parenteral and pulmonary, whereby resolving these challenges will be beneficial to patients as they are less invasive and comfortable in terms of administration. This review compiles recent work on rotigotine delivery, challenges and its future perspective.
    Matched MeSH terms: Dopamine Agonists
  13. Multilevel Pharmacological Effects of Antipsychotics in Potential Glioblastoma Treatment
    Awuah WA, Kalmanovich J, Mehta A, Huang H, Abdul-Rahman T, Cheng Ng J, et al.
    Curr Top Med Chem, 2023;23(5):389-402.
    PMID: 36593538 DOI: 10.2174/1568026623666230102095836
    Glioblastoma Multiforme (GBM) is a debilitating type of brain cancer with a high mortality rate. Despite current treatment options such as surgery, radiotherapy, and the use of temozolomide and bevacizumab, it is considered incurable. Various methods, such as drug repositioning, have been used to increase the number of available treatments. Drug repositioning is the use of FDA-approved drugs to treat other diseases. This is possible because the drugs used for this purpose have polypharmacological effects. This means that these medications can bind to multiple targets, resulting in multiple mechanisms of action. Antipsychotics are one type of drug used to treat GBM. Antipsychotics are a broad class of drugs that can be further subdivided into typical and atypical classes. Typical antipsychotics include chlorpromazine, trifluoperazine, and pimozide. This class of antipsychotics was developed early on and primarily works on dopamine D2 receptors, though it can also work on others. Olanzapine and Quetiapine are examples of atypical antipsychotics, a category that was created later. These medications have a high affinity for serotonin receptors such as 5- HT2, but they can also act on dopamine and H1 receptors. Antipsychotic medications, in the case of GBM, also have other effects that can affect multiple pathways due to their polypharmacological effects. These include NF-B suppression, cyclin deregulation, and -catenin phosphorylation, among others. This review will delve deeper into the polypharmacological, the multiple effects of antipsychotics in the treatment of GBM, and an outlook for the field's future progression.
    Matched MeSH terms: Dopamine
  14. Generation of glial cell-derived neurotrophic factor (gdnf) morphants in zebrafish larvae by cerebroventricular microinjection of vivo morpholino
    Noor SM, Wong CED, Wong PF, Norazit A
    Methods Cell Biol, 2024;181:17-32.
    PMID: 38302238 DOI: 10.1016/bs.mcb.2022.09.004
    Dopaminergic neurons in the brain are an important source of dopamine, which is a crucial neurotransmitter for wellbeing, memory, reward, and motor control. Deficiency of dopamine due to advanced age and accumulative dopaminergic neuron defects can lead to movement disorders such as Parkinson's disease. Glial cell-derived neurotrophic factor (GDNF) is one of many factors involved in dopaminergic neuron development and/or survival. However, other endogenous GDNF functions in the brain await further investigation. Zebrafish is a well-established genetic model for neurodevelopment and neurodegeneration studies. Importantly, zebrafish shares approximately 70% functional orthologs with human genes including GDNF. To gain a better understanding on the precise functional role of gdnf in dopaminergic neurons, our laboratory devised a targeted knockdown of gdnf in the zebrafish larval brain using vivo morpholino. Here, detailed protocols on the generation of gdnf morphants using vivo morpholino are outlined. This method can be applied for targeting of genes in the brain to determine specific spatiotemporal gene function in situ.
    Matched MeSH terms: Dopamine
  15. Fulltext Plasmonic Refractive Index Sensor Enhanced with Chitosan/Au Bilayer Thin Film for Dopamine Detection
    Eddin FBK, Fen YW, Liew JYC, Daniyal WMEMM
    Biosensors (Basel), 2022 Dec 03;12(12).
    PMID: 36551091 DOI: 10.3390/bios12121124
    Surface plasmonic sensors have received considerable attention, found extensive applications, and outperformed conventional optical sensors. In this work, biopolymer chitosan (CS) was used to prepare the bilayer structure (CS/Au) of a plasmonic refractive index sensor for dopamine (DA) detection. The sensing characteristics of the developed plasmonic sensor were evaluated. Increasing DA concentrations significantly shifted the SPR dips. The sensor exhibited stability and a refractive index sensitivity of 8.850°/RIU in the linear range 0.1 nM to 1 µM with a detection limit of 0.007 nM and affinity constant of 1.383 × 108 M-1. The refractive index and thickness of the CS/Au structure were measured simultaneously by fitting the obtained experimental findings to theoretical data based on Fresnel equations. The fitting yielded the refractive index values n (1.5350 ± 0.0001) and k (0.0150 ± 0.0001) for the CS layer contacting 0.1 nM of DA, and the thickness, d was (15.00 ± 0.01) nm. Then, both n and d values increased by increasing DA concentrations. In addition, the changes in the FTIR spectrum and the variations in sensor surface roughness and structure obtained by AFM analysis confirmed DA adsorption on the sensing layer. Based on these observations, CS/Au bilayer has enhanced the performance of this plasmonic sensor, which showed promising importance as a simple, low-cost, and reliable platform for DA sensing.
    Matched MeSH terms: Dopamine
  16. Real time monitoring of dopamine release evoked by mitragynine (Kratom): An insight through electrochemical sensor
    Effendy MA, Yunusa S, Zain ZM, Hassan Z
    Neurosci Lett, 2021 10 15;763:136183.
    PMID: 34418508 DOI: 10.1016/j.neulet.2021.136183
    BACKGROUND: Mitragynine, the major indole alkaloid from Mitragyna speciosa has been reported previously to possess abuse liability. However, there are insufficient data suggesting the mechanism through which this pharmacological agent causes addiction.

    AIMS: In this study, we investigated the effects of mitragynine on dopamine (DA) level and dopamine transporter (DAT) expression from the rat's frontal cortex.

    METHODS: DA level was recorded in the brain samples of animals treated with acute or repeated exposure for 4 consecutive days with either vehicle or mitragynine (1 and 30 mg/kg) using electrochemical sensor. Animals were then decapitated and the brain regions were removed, snap-frozen in liquid nitrogen and immediately stored at -80 °C. DA level was quantified using Enzyme linked immunosorbent assay (ELISA) kits and DAT gene expression was determined using quantitative real time polymerase chain reaction (RT-qPCR).

    RESULTS/OUTCOME: Mitragynine (1 and 30 mg/kg) did not increase DA release following acute treatment, however, after repeated exposure at day 4, mitragynine significantly and dose dependently increased DA release in the frontal cortex. In this study, we also observed a significant increase in DAT mRNA expression at day 4 in group treated with mitragynine (30 mg/kg).

    CONCLUSION/INTERPRETATION: Data from this study indicates that mitragynine significantly increased DA release when administered repeatedly, increased in DAT mRNA expression with the highest tested dose (30 mg/kg). Therefore, the rewarding effects observed after mitragynine administration could be due to its ability to increase DA content in certain areas of the brain especially the frontal cortex.

    Matched MeSH terms: Dopamine/analysis; Dopamine/metabolism*; Dopamine Plasma Membrane Transport Proteins/analysis; Dopamine Plasma Membrane Transport Proteins/metabolism*
  17. Fulltext Simultaneous electrochemical detection of dopamine and ascorbic acid using an iron oxide/reduced graphene oxide modified glassy carbon electrode
    Peik-See T, Pandikumar A, Nay-Ming H, Hong-Ngee L, Sulaiman Y
    Sensors (Basel), 2014;14(8):15227-43.
    PMID: 25195850 DOI: 10.3390/s140815227
    The fabrication of an electrochemical sensor based on an iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE) and its simultaneous detection of dopamine (DA) and ascorbic acid (AA) is described here. The Fe3O4/rGO nanocomposite was synthesized via a simple, one step in-situ wet chemical method and characterized by different techniques. The presence of Fe3O4 nanoparticles on the surface of rGO sheets was confirmed by FESEM and TEM images. The electrochemical behavior of Fe3O4/rGO/GCE towards electrocatalytic oxidation of DA was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analysis. The electrochemical studies revealed that the Fe3O4/rGO/GCE dramatically increased the current response against the DA, due to the synergistic effect emerged between Fe3O4 and rGO. This implies that Fe3O4/rGO/GCE could exhibit excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA. Moreover, the modified sensor electrode portrayed sensitivity and selectivity for simultaneous determination of AA and DA. The observed DPVs response linearly depends on AA and DA concentration in the range of 1-9 mM and 0.5-100 µM, with correlation coefficients of 0.995 and 0.996, respectively. The detection limit of (S/N = 3) was found to be 0.42 and 0.12 µM for AA and DA, respectively.
    Matched MeSH terms: Dopamine/isolation & purification*
  18. Fulltext The Principle of Nanomaterials Based Surface Plasmon Resonance Biosensors and Its Potential for Dopamine Detection
    Kamal Eddin FB, Fen YW
    Molecules, 2020 Jun 15;25(12).
    PMID: 32549390 DOI: 10.3390/molecules25122769
    For a healthy life, the human biological system should work in order. Scheduled lifestyle and lack of nutrients usually lead to fluctuations in the biological entities levels such as neurotransmitters (NTs), proteins, and hormones, which in turns put the human health in risk. Dopamine (DA) is an extremely important catecholamine NT distributed in the central nervous system. Its level in the body controls the function of human metabolism, central nervous, renal, hormonal, and cardiovascular systems. It is closely related to the major domains of human cognition, feeling, and human desires, as well as learning. Several neurological disorders such as schizophrenia and Parkinson's disease are related to the extreme abnormalities in DA levels. Therefore, the development of an accurate, effective, and highly sensitive method for rapid determination of DA concentrations is desired. Up to now, different methods have been reported for DA detection such as electrochemical strategies, high-performance liquid chromatography, colorimetry, and capillary electrophoresis mass spectrometry. However, most of them have some limitations. Surface plasmon resonance (SPR) spectroscopy was widely used in biosensing. However, its use to detect NTs is still growing and has fascinated impressive attention of the scientific community. The focus in this concise review paper will be on the principle of SPR sensors and its operation mechanism, the factors that affect the sensor performance. The efficiency of SPR biosensors to detect several clinically related analytes will be mentioned. DA functions in the human body will be explained. Additionally, this review will cover the incorporation of nanomaterials into SPR biosensors and its potential for DA sensing with mention to its advantages and disadvantages.
    Matched MeSH terms: Dopamine/chemistry*
  19. Normobaric hyperoxia treatment in traumatic brain injury: a focus on basal ganglia
    Fatin Azwa Haruddin
    Orient Neuron Nexus, 2010;1(1):13-16.
    MyJurnal
    Traumatic brain injury (TBI) is known to inflict significant morbidity and mortality worldwide. In severe TBI cases, the resulting physical and cognitive impairments incur high management and rehabilitation costs that crucially involve monitoring intracranial pressure (ICP) and improving brain oxygenation. Normobaric Hyperoxia Treatment (NBOT) is a therapeutic strategy to improve brain oxygen metabolism and to decrease ICP by reducing tissue swelling and deactivating toxin. NBOT is administered by increasing the inspired oxygen concentration to 100% in normal atmospheric pressure. Previous studies involving NBOT had explored its effectiveness to salvage the TBI-related cognitive and motor deficits. However, the focus of these studies has frequently been on the cortical lesions despite the known facts that TBI often inflicts tissue damage to the subcortical areas such as the basal ganglia. There are growing evidence to support recent functional theories that implicate a pivotal role of the basal ganglia in regulating normal movements and cognition through dopamine (DA) and glutamate interaction. Thus, tissue damages leading to TBI-related motor and cognitive deficits may involve the different affected brain regions. This minireview attempts to highlight the key processes involved in the pathophysiology of severe TBI and offers insights into the role of NBOT by exploring its potential effects on the cerebral energy metabolism and gene expression patterns of dopamine receptor in a mouse model.
    Matched MeSH terms: Dopamine; Receptors, Dopamine
  20. Fulltext Behavioural effects of APH199, a selective dopamine D4 receptor agonist, in animal models
    Chestnykh D, Graßl F, Pfeifer C, Dülk J, Ebner C, Walters M, et al.
    Psychopharmacology (Berl), 2023 Apr;240(4):1011-1031.
    PMID: 36854793 DOI: 10.1007/s00213-023-06347-1
    RATIONALE: The dopamine D4 receptors (DRD4) play a key role in numerous brain functions and are involved in the pathogenesis of various psychiatric disorders. DRD4 ligands have been shown to moderate anxiety, reward and depression-like behaviours, and cognitive impairments. Despite a series of promising but ambiguous findings, the therapeutic advantages of DRD4 stimulation remain elusive.

    OBJECTIVES: The investigation focused on the behavioural effects of the recently developed DRD4 agonist, APH199, to evaluate its impact on anxiety, anhedonia, behavioural despair, establishment and retrieval of alcohol reinforcement, and amphetamine (AMPH)-induced symptoms.

    METHODS: Male C57BL/6 J mice and Sprague-Dawley rats were examined in five independent experiments. We assessed APH199 (0.1-5 mg/kg, i.p.) effects on a broad range of behavioural parameters in the open field (OF) test, conditioned place preference test (CPP), elevated plus maze (EPM), light-dark box (LDB), novelty suppressed feeding (NSF), forced swim test (FST), sucrose preference test (SPT), AMPH-induced hyperlocomotion test (AIH), and prepulse inhibition (PPI) of the acoustic startle response in AMPH-sensitized rats.

    RESULTS: APH199 caused mild and sporadic anxiolytic and antidepressant effects in EPM and FST, but no remarkable impact on behaviour in other tests in mice. However, we found a significant increase in AMPH-induced hyperactivity, suggesting an exaggeration of the psychotic-like responses in the AMPH-sensitized rats.

    CONCLUSIONS: Our data challenged the hypothesis of the therapeutic benefits of DRD4 agonists, pointing out a possible aggravation of psychosis. We suggest a need for further preclinical studies to ensure the safety of antipsychotics with DRD4 stimulating properties.

    Matched MeSH terms: Receptors, Dopamine D4*
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