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NeuroImmune Pharmacology and... Mar 2024HIV-1 Tat (transactivator of transcription) protein disrupts dopaminergic transmission and potentiates the rewarding effects of cocaine. Allosteric modulators of the...
OBJECTIVES
HIV-1 Tat (transactivator of transcription) protein disrupts dopaminergic transmission and potentiates the rewarding effects of cocaine. Allosteric modulators of the dopamine transporter (DAT) have been shown to reverse Tat-induced DAT dysfunction. We hypothesized that a novel DAT allosteric modulator, SRI-30827, would counteract Tat-induced potentiation of cocaine reward.
METHODS
Doxycycline (Dox)-inducible Tat transgenic (iTat-tg) mice and their G-tg (Tat-null) counterparts were tested in a cocaine conditioned place preference (CPP) paradigm. Mice were treated 14 days with saline, or Dox (100 mg/kg/day, i.p.) to induce Tat protein. Upon induction, mice were place conditioned two days with cocaine (10 mg/kg/day) after a 1-h daily intracerebroventricular (i.c.v.) pretreatment with SRI-30827 (1 nmol) or a vehicle control, and final place preference assessed as a measure of cocaine reward.
RESULTS
Dox-treatment significantly potentiated cocaine-CPP in iTat-tg mice over the response of saline-treated control littermates. SRI-30827 treatment eliminated Tat-induced potentiation without altering normal cocaine-CPP in saline-treated mice. Likewise, SRI-30827 did not alter cocaine-CPP in both saline- and Dox-treated G-tg mice incapable of expressing Tat protein.
CONCLUSIONS
These findings add to a growing body of evidence that allosteric modulation of DAT could provide a promising therapeutic intervention for patients with comorbid HIV-1 and cocaine use disorder (CUD).
PubMed: 38711842
DOI: 10.1515/nipt-2023-0022 -
Frontiers in Neurology 2024Diagnosing Dementia with Lewy Bodies (DLB) remains a challenge in clinical practice. The use of I-ioflupane (DaTscan) SPECT imaging, which detects reduced dopamine... (Review)
Review
BACKGROUND
Diagnosing Dementia with Lewy Bodies (DLB) remains a challenge in clinical practice. The use of I-ioflupane (DaTscan) SPECT imaging, which detects reduced dopamine transporter (DAT) uptake-a key biomarker in DLB diagnosis-could improve diagnostic accuracy. However, DAT imaging is underutilized despite its potential, contributing to delays and suboptimal patient management.
METHODS
This review evaluates DLB diagnostic practices and challenges faced within the U.S. by synthesizing information from current literature, consensus guidelines, expert opinions, and recent updates on DaTscan FDA filings. It contrasts DAT SPECT with alternative biomarkers, provides recommendations for when DAT SPECT imaging may be indicated and discusses the potential of emerging biomarkers in enhancing diagnostic approaches.
RESULTS
The radiopharmaceutical I-ioflupane for SPECT imaging was initially approved in Europe (2000) and later in the US (2011) for Parkinsonism/Essential Tremor. Its application was extended in 2022 to include the diagnosis of DLB. DaTscan's diagnostic efficacy for DLB, with its sensitivity, specificity, and predictive values, confirms its clinical utility. However, US implementation faces challenges such as insurance barriers, costs, access issues, and regional availability disparities.
CONCLUSION
I-ioflupane SPECT Imaging is indicated for DLB diagnosis and differential diagnosis of Alzheimer's Disease, particularly in uncertain cases. Addressing diagnostic obstacles and enhancing physician-patient education could improve and expedite DLB diagnosis. Collaborative efforts among neurologists, geriatric psychiatrists, psychologists, and memory clinic staff are key to increasing diagnostic accuracy and care in DLB management.
PubMed: 38711561
DOI: 10.3389/fneur.2024.1395413 -
Journal of Biomolecular Structure &... May 2024In a step towards understanding the structure-property relationship among Synthetic Cathinones (SCs), a combined methodology based on Density Functional Theory (DFT),...
In a step towards understanding the structure-property relationship among Synthetic Cathinones (SCs), a combined methodology based on Density Functional Theory (DFT), Administration, Distribution, Metabolism, Excretion, and Toxicity (ADMET) predictions, docking and molecular dynamics simulations have been applied to correlate physicochemical descriptors of various SCs to their biological activity. The results from DFT and molecular docking studies correlate well with each other explaining the biological activity trends of the studied SCs. Quantum mechanical descriptors viz. polarizability, electron affinity, ionization potential, chemical hardness, electronegativity, molecular electrostatic potential, and ion interaction studies unravel the distinguishingly reactive nature of Group D (pyrrolidine substituted) and Group E (methylenedioxy and pyrrolidine substituted) compounds. According to ADMET analysis, Group D and Group E molecules have a higher probability of permeating through the blood-brain barrier. Molecular docking results indicate that Phe76, Ala77, Asp79, Val152, Tyr156, Phe320, and Phe326 constitute the binding pocket residues of hDAT in which the most active ligands MDPV, MDPBP, and MDPPP are bound. Finally, to validate the derived quantum chemical descriptors and docking results, Molecular Dynamics (MD) simulations are performed with homology-modelled hDAT (human dopamine transporter). The MD simulation results revealed that the majority of SCs remain stable within the hDAT protein's active sites via non-bonded interactions after 100 ns long simulations. The findings from DFT, ADMET analysis, molecular docking, and molecular dynamics simulation studies complement each other suggesting that pyrrolidine-substituted SCs (Group D and E), specifically, MPBP and PVN are proven potent SCs along with MDPV, validating various experimental observations.Communicated by Ramaswamy H. Sarma.
PubMed: 38698732
DOI: 10.1080/07391102.2024.2335303 -
Neuropsychopharmacology : Official... May 2024The catecholamine neuromodulators dopamine and norepinephrine are implicated in motor function, motivation, and cognition. Although roles for striatal dopamine in these...
The catecholamine neuromodulators dopamine and norepinephrine are implicated in motor function, motivation, and cognition. Although roles for striatal dopamine in these aspects of behavior are well established, the specific roles for cortical catecholamines in regulating striatal dopamine dynamics and behavior are less clear. We recently showed that elevating cortical dopamine but not norepinephrine suppresses hyperactivity in dopamine transporter knockout (DAT-KO) mice, which have elevated striatal dopamine levels. In contrast, norepinephrine transporter knockout (NET-KO) mice have a phenotype distinct from DAT-KO mice, as they show elevated extracellular cortical catecholamines but reduced baseline striatal dopamine levels. Here we evaluated the consequences of altered catecholamine levels in NET-KO mice on cognitive flexibility and striatal dopamine dynamics. In a probabilistic reversal learning task, NET-KO mice showed enhanced reversal learning, which was consistent with larger phasic dopamine transients (dLight) in the dorsomedial striatum (DMS) during reward delivery and reward omission, compared to WT controls. Selective depletion of dorsal medial prefrontal cortex (mPFC) norepinephrine in WT mice did not alter performance on the reversal learning task but reduced nestlet shredding. Surprisingly, NET-KO mice did not show altered breakpoints in a progressive ratio task, suggesting intact food motivation. Collectively, these studies show novel roles of cortical catecholamines in the regulation of tonic and phasic striatal dopamine dynamics and cognitive flexibility, updating our current views on dopamine regulation and informing future therapeutic strategies to counter multiple psychiatric disorders.
PubMed: 38698264
DOI: 10.1038/s41386-024-01868-5 -
NPJ Parkinson's Disease May 2024Resilience in neuroscience generally refers to an individual's capacity to counteract the adverse effects of a neuropathological condition. While resilience mechanisms...
Resilience in neuroscience generally refers to an individual's capacity to counteract the adverse effects of a neuropathological condition. While resilience mechanisms in Alzheimer's disease are well-investigated, knowledge regarding its quantification, neurobiological underpinnings, network adaptations, and long-term effects in Parkinson's disease is limited. Our study involved 151 Parkinson's patients from the Parkinson's Progression Marker Initiative Database with available Magnetic Resonance Imaging, Dopamine Transporter Single-Photon Emission Computed Tomography scans, and clinical information. We used an improved prediction model linking neuropathology to symptom severity to estimate individual resilience levels. Higher resilience levels were associated with a more active lifestyle, increased grey matter volume in motor-associated regions, a distinct structural connectivity network and maintenance of relative motor functioning for up to a decade. Overall, the results indicate that relative maintenance of motor function in Parkinson's patients may be associated with greater neuronal substrate, allowing higher tolerance against neurodegenerative processes through dynamic network restructuring.
PubMed: 38697984
DOI: 10.1038/s41531-024-00699-x -
EJNMMI Radiopharmacy and Chemistry May 2024Parkinson's disease is a neurodegenerative disorder that is characterized by a degeneration of the dopaminergic system. Dopamine transporter (DAT) positron emission...
BACKGROUND
Parkinson's disease is a neurodegenerative disorder that is characterized by a degeneration of the dopaminergic system. Dopamine transporter (DAT) positron emission tomography (PET) imaging has emerged as a powerful and non-invasive method to quantify dopaminergic function in the living brain. The PET radioligand, [F]FE-PE2I, a cocaine chemical derivative, has shown promising properties for in vivo PET imaging of DAT, including high affinity and selectivity for DAT, excellent brain permeability, and favorable metabolism. The aim of the current study was to scale up the production of [F]FE-PE2I to fulfil the increasing clinical demand for this tracer.
RESULTS
Thus, a fully automated and GMP-compliant production procedure has been developed using a commercially available radiosynthesis module GE TRACERLab FX2 N. [F]FE-PE2I was produced with a radiochemical yield of 39 ± 8% (n = 4, relative [F]F delivered to the module). The synthesis time was 70 min, and the molar activity was 925.3 ± 763 GBq/µmol (250 ± 20 Ci/µmol). The produced [F]FE-PE2I was stable over 6 h at room temperature.
CONCLUSION
The protocol reliably provides a sterile and pyrogen-free GMP-compliant product.
PubMed: 38696063
DOI: 10.1186/s41181-024-00269-9 -
Movement Disorders Clinical Practice Jun 2024As the diagnosis of Parkinson's disease (PD) is fundamentally clinical, the usefulness of ioflupane (I) single-photon emission computed tomography (SPECT) or DaTSCAN as... (Review)
Review
BACKGROUND
As the diagnosis of Parkinson's disease (PD) is fundamentally clinical, the usefulness of ioflupane (I) single-photon emission computed tomography (SPECT) or DaTSCAN as a diagnostic tool has been a matter of debate for years. The performance of DaTSCAN is generally recommended in the follow-up of patients with a clinically uncertain diagnosis, especially in those with a suspected essential tremor, drug-induced parkinsonism, or vascular parkinsonism. However, there is a dearth of DaTSCAN findings regarding neurodegenerative parkinsonisms besides PD and atypical parkinsonisms. To date, a specific nigrostriatal dopamine uptake pattern that would help differentiate PD from the most frequent atypical parkinsonisms is yet to be described. This fact is further complicated by the possible visualization of abnormalities in the uptake pattern in patients with rarer neurodegenerative parkinsonisms.
OBJECTIVES
We aimed to summarize the current literature regarding DaTSCAN findings in patients with rare neurodegenerative parkinsonisms.
METHODS
The PubMed database was systematically screened for studies in English or Spanish up to October 15, 2023, using search terms "DaTSCAN", "ioflupane", "DaT-SPECT", "123I-FP-CIT SPECT", "dopamine transporter imaging", and "[123I] FP-CIT SPECT". Duplicated publications and studies regarding PD, atypical parkinsonisms, dystonia-parkinsonism, essential tremor, and parkinsonism due to non-degenerative causes were excluded.
RESULTS
The obtained results were reviewed and summarized, including DaTSCAN findings in fragile X-associated tremor/ataxia syndrome, prion diseases, Huntington's disease, spinocerebellar ataxia, hereditary spastic paraparesis, metabolic disorders, and other diseases (anti-IgLON5 disease, ring chromosome 20 syndrome, chorea-acanthocytosis, and neuronal ceroid lipofuscinosis).
CONCLUSIONS
This review highlights the need to determine in the future the utility and cost-effectiveness of DaTSCAN, both as a diagnostic and a prognostic tool, in patients with parkinsonian symptoms in rare neurodegenerative diseases.
Topics: Humans; Tomography, Emission-Computed, Single-Photon; Parkinsonian Disorders; Tropanes; Parkinson Disease
PubMed: 38693679
DOI: 10.1002/mdc3.14055 -
Biological Psychiatry. Cognitive... Apr 2024Internet gaming disorder (IGD) can lead to psychological problems and cause behavioral problems in individuals. Traditional interventions have been ineffective in...
BACKGROUND
Internet gaming disorder (IGD) can lead to psychological problems and cause behavioral problems in individuals. Traditional interventions have been ineffective in treating IGDs. Meanwhile, mindfulness meditation (MM) is an emerging method that has proven to be effective for treating psychiatry disorders. In this study, MM was used to intervene in IGD and to explore its neural mechanism.
METHODS
Eighty participants were recruited through advertisements. Eventually, 61 completed the one-month training (MM/progressive muscle relaxation: 31/30), including a pre-test, eight training sessions, and a post-test. Regional homogeneity and degree centrality were calculated and the tests (pre- and post-) and group (MM and PMR) ANOVA was performed. The overlapping results were obtained as ROI for functional connectivity (FC) analyses. Behavioral data and neurotransmitters correlated with FC.
RESULTS
Compared to PMR, MM decreased the severity of addiction and game craving in IGD. Brain imaging results showed that the FC between and within the executive control and default mode networks (DMN)/reward-related regions were enhanced. Significant negative correlations were observed between the FC and dopamine receptors D2, dopamine transporter (DAT), and acetylcholine receptors VAChT. Significant positive correlations were observed between FCs and serotonin and aminobutyric acid receptors.
CONCLUSIONS
This study confirmed the effectiveness of MM in treating IGD. MM altered the default mode and enhanced the top-down control over game cravings. These findings were revealed by the correlations between brain regions and behavioral and bio-chemical effects. The results showed the neural mechanism of MM in reducing IGD and lay the foundation for future research.
PubMed: 38692393
DOI: 10.1016/j.bpsc.2024.04.011 -
The Science of the Total Environment Jul 2024The misuse of antitussives preparations is a continuing problem in the world, and imply that they might have potential new psychoactive substances (NPS) activity....
The misuse of antitussives preparations is a continuing problem in the world, and imply that they might have potential new psychoactive substances (NPS) activity. However, few study focus on their ecological toxicity towards fish. In the present study, the machine learning (ML) methods gcForest and random forest (RF) were employed to predict NPS activity in 30 antitussives. The potential toxic target, mode of action (MOA), acute toxicity and chronic toxicity to fish were further investigated. The results showed that both gcForest and RF achieved optimal performance when utilizing combined features of molecular fingerprint (MF) and molecular descriptor (MD), with area under the curve (AUC) = 0.99, accuracy >0.94 and f1 score > 0.94, and were applied to screen the NPS activity in antitussives. A total of 15 antitussives exhibited potential NPS activity, including frequently-used substances like codeine and dextromethorphan. The binding affinity of these antitussives with zebrafish dopamine transporter (zDAT) was high, and even surpassing that of some traditional narcotics and NPS. Some antitussives formed hydrogen bonds or salt bridges with aspartate (Asp) 95, tyrosine (Tyr) 171 of zDAT. For the ecotoxicity, the MOA of these 15 antitussives in fish was predicted as narcosis. The prenoxdiazin, pholcodine, codeine, dextromethorphan and dextrorphan exhibited very toxic/toxic to fish. It was necessary to pay close attention to the ecotoxicity of these antitussives. In this study, the integration of ML, molecular docking and ECOSAR approaches are powerful tools for understanding the toxicity profiles and ecological hazards posed by new pollutants.
Topics: Animals; Water Pollutants, Chemical; Psychotropic Drugs; Zebrafish; Fishes; Machine Learning
PubMed: 38692322
DOI: 10.1016/j.scitotenv.2024.172872 -
Cellular and Molecular Life Sciences :... May 2024Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted...
Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted by their mammalian equivalents. The cephalic sheath (CEPsh) glia, which are known to be the counterparts of mammalian astrocytes, are enriched with two nuclear hormone receptors (NHRs)-NHR-210 and NHR-231. This unique enrichment makes the CEPsh glia and these NHRs intriguing subjects of study concerning neuronal health. We endeavored to assess the role of these NHRs in neurodegenerative diseases and related functional processes, using transgenic C. elegans expressing human alpha-synuclein. We employed RNAi-mediated silencing, followed by behavioural, functional, and metabolic profiling in relation to suppression of NHR-210 and 231. Our findings revealed that depleting nhr-210 changes dopamine-associated behaviour and mitochondrial function in human alpha synuclein-expressing strains NL5901 and UA44, through a putative target, pgp-9, a transmembrane transporter. Considering the alteration in mitochondrial function and the involvement of a transmembrane transporter, we performed metabolomics study via HR-MAS NMR spectroscopy. Remarkably, substantial modifications in ATP, betaine, lactate, and glycine levels were seen upon the absence of nhr-210. We also detected considerable changes in metabolic pathways such as phenylalanine, tyrosine, and tryptophan biosynthesis metabolism; glycine, serine, and threonine metabolism; as well as glyoxalate and dicarboxylate metabolism. In conclusion, the deficiency of the nuclear hormone receptor nhr-210 in alpha-synuclein expressing strain of C. elegans, results in altered mitochondrial function, coupled with alterations in vital metabolite levels. These findings underline the functional and physiological importance of nhr-210 enrichment in CEPsh glia.
Topics: Animals; Caenorhabditis elegans; Mitochondria; Neuroglia; Parkinson Disease; Humans; alpha-Synuclein; Disease Models, Animal; Caenorhabditis elegans Proteins; Animals, Genetically Modified; Receptors, Cytoplasmic and Nuclear; Dopamine; Metabolomics; RNA Interference
PubMed: 38691171
DOI: 10.1007/s00018-024-05179-2