Practical Overview of 123I-Ioflupane Imaging in Parkinsonian Syndromes.

Parkinsonian syndromes are a heterogeneous group of progressive neurodegenerative disorders involving the nigrostriatal dopaminergic pathway and are characterized by a wide spectrum of motor and nonmotor symptoms. These syndromes are quite common and can profoundly impact the lives of patients and their families. In addition to classic Parkinson disease, parkinsonian syndromes include multiple additional disorders known collectively as Parkinson-plus syndromes or atypical parkinsonism. These are characterized by the classic parkinsonian motor symptoms with additional distinguishing clinical features. Dopamine transporter SPECT has been developed as a diagnostic tool to assess the levels of dopamine transporters in the striatum. This imaging assessment, which uses iodine 123 (123I) ioflupane, can be useful to differentiate parkinsonian syndromes caused by nigrostriatal degeneration from other clinical mimics such as essential tremor or psychogenic tremor. Dopamine transporter imaging plays a crucial role in diagnosing parkinsonian syndromes, particularly in patients who do not clearly fulfill the clinical criteria for diagnosis. Diagnostic clarification can allow early treatment in appropriate patients and avoid misdiagnosis. At present, only the qualitative interpretation of dopamine transporter SPECT is approved by the U.S. Food and Drug Administration, but quantitative interpretation is often used to supplement qualitative interpretation. The authors provide an overview of patient preparation, common imaging findings, and potential pitfalls that radiologists and nuclear medicine physicians should know when performing and interpreting dopamine transporter examinations. Alternatives to 123I-ioflupane imaging for the evaluation of nigrostriatal degeneration are also briefly discussed. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Intenzo and Colarossi in this issue.

Supplementation with vitamins D3 and a mitigates Parkinsonism in a haloperidol mice model.

BACKGROUND: Earlier reports suggest that vitamin D3 (Vit D3) supplementation attenuates Parkinsonism in drug-induced motor deficits. Moreover, the function of Vit D3 may be optimized by co-administration with vitamin A (Vit A). In line with the synergistic interplay between vitamins, we hypothesized that the efficacy of Vit D3 to attenuate Parkinsonism in a haloperidol-induced mouse model of motor deficits would be more potent when concomitantly administered with Vit A. METHODS: Thirty-six (36) adult male mice were randomly divided into six groups of six animals each: the control group, the PD model (haloperidol-treated only group) (-D2), and four other groups treated with haloperidol together with either one or two of the following vitamin supplementations: Vit D3, Vit A, Vit D3 +VA, or bromocriptine a known PD drug respectively. Motor functions were assessed using a battery of neurobehavioral tests in experimental animals, after which brain tissues were harvested and processed for biochemical and histomorphological analysis. RESULTS: We recorded a significant decline in motor activity in the PD mice model treated with haloperidol alone compared to other experimental groups that received vitamin supplementations. The significant decrease in motor activity observed in the PD mice model corresponded with marked neurodegenerative features in the cytoarchitecture of the pyramidal cells in the striatum and primary motor cortex (M1). Furthermore, the haloperidol-induced PD mice model treated with Vit D3 +Vit A showed significant improvement in motor activity and attenuation of oxidative stress levels and neurodegenerative features compared to other groups treated with Vit A, Vit D3 and bromocriptine alone. CONCLUSION: Altogether, our findings suggest that concomitant administration of both Vit D3 and Vit A prevents the development of Parkinsonism features in the haloperidol mouse model of motor deficit. Thus, supplementation with Vit D3 +Vit A may be a viable option for slowing the onset and progression of motor deficits.

Modeling Synaptic Integration of Bursty and ß Oscillatory Inputs in Ventromedial Motor Thalamic Neurons in Normal and Parkinsonian States.

The ventromedial motor thalamus (VM) is implicated in multiple motor functions and occupies a central position in the cortico-basal ganglia-thalamocortical loop. It integrates glutamatergic inputs from motor cortex (MC) and motor-related subcortical areas, and it is a major recipient of inhibition from basal ganglia. Previous in vitro experiments performed in mice showed that dopamine depletion enhances the excitability of thalamocortical (TC) neurons in VM due to reduced M-type potassium currents. To understand how these excitability changes impact synaptic integration in vivo, we constructed biophysically detailed mouse VM TC model neurons fit to normal and dopamine-depleted conditions, using the NEURON simulator. These models allowed us to assess the influence of excitability changes with dopamine depletion on the integration of synaptic inputs expected in vivo We found that VM neuron models in the dopamine-depleted state showed increased firing rates with the same synaptic inputs. Synchronous bursting in inhibitory input from the substantia nigra pars reticulata (SNR), as observed in parkinsonian conditions, evoked a postinhibitory firing rate increase with a longer duration in dopamine-depleted than control conditions, due to different M-type potassium channel densities. With ß oscillations in the inhibitory inputs from SNR and the excitatory inputs from cortex, we observed spike-phase locking in the activity of the models in normal and dopamine-depleted states, which relayed and amplified the oscillations of the inputs, suggesting that the increased ß oscillations observed in VM of parkinsonian animals are predominantly a consequence of changes in the presynaptic activity rather than changes in intrinsic properties.

Transcranial photobiomodulation ameliorates midbrain and striatum neurochemical impairments and behavioral deficits in reserpine-induced parkinsonism in rats.

Photobiomodulation (PBM) of deep brain structures through transcranial infrared irradiation might be an effective treatment for Parkinson's disease (PD). However, the mechanisms underlying this intervention should be elucidated to optimize the therapeutic outcome and maximize therapeutic efficacy. The present study aimed at investigating the oxidative stress-related parameters of malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) and the enzymatic activities of sodium-potassium-ATPase (Na+, K+-ATPase), Acetylcholinesterase (AChE), and monoamine oxidase (MAO) and monoamine levels (dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in the midbrain and striatum of reserpine-induced PD in an animal model treated with PBM. Furthermore, the locomotor behavior of the animals has been determined by the open field test. Animals were divided into three groups; the control group, the PD-induced model group, and the PD-induced model treated with the PBM group. Non-invasive treatment of animals for 14 days with 100 mW, 830 nm laser has demonstrated successful attainment in the recovery of oxidative stress, and enzymatic activities impairments induced by reserpine (0.2 mg/kg) in both midbrain and striatum of adult male Wistar rats. PBM also improved the decrease in DA, NE, and 5-HT in the investigated brain regions. On a behavioral level, animals showed improvement in their locomotion activity. These findings have shed more light on some mechanisms underlying the treatment potential of PBM and displayed the safety, easiness, and efficacy of PBM treatment as an alternative to pharmacological treatment for PD.

Striatal and thalamic automatic segmentation, morphology, and clinical correlates in Parkinsonism: Parkinson's disease, multiple system atrophy and progressive supranuclear palsy.

Parkinson's disease (PD), multisystem atrophy (MSA), and progressive supranuclear palsy (PSP) present similarly with bradykinesia, tremor, rigidity, and cognitive impairments. Neuroimaging studies have found differential changes in the nigrostriatal pathway in these disorders, however whether the volume and shape of specific regions within this pathway can distinguish between atypical Parkinsonian disorders remains to be determined. This paper investigates striatal and thalamic volume and morphology as distinguishing biomarkers, and their relationship to neuropsychiatric symptoms. Automatic segmentation to calculate volume and shape analysis of the caudate nucleus, putamen, and thalamus were performed in 18 PD patients, 12 MSA, 15 PSP, and 20 healthy controls, then correlated with clinical measures. PSP bilateral thalami and right putamen were significantly smaller than controls, but not MSA or PD. The left caudate and putamen significantly correlated with the Neuropsychiatric Inventory total score. Bilateral thalamus, caudate, and left putamen had significantly different morphology between groups, driven by differences between PSP and healthy controls. This study demonstrated that PSP patient striatal and thalamic volume and shape are significantly different when compared with controls. Parkinsonian disorders could not be differentiated on volumetry or morphology, however there are trends for volumetric and morphological changes associated with PD, MSA, and PSP.

Neurological update: non-motor symptoms in atypical parkinsonian syndromes.

Among people with Parkinson's disease (PD), non-motor symptoms (NMS) are a well-recognised cause of significant morbidity and poor quality of life. Yet, it is only more recently that NMS have been recognised to affect the lives of patients with atypical parkinsonian syndromes in a similar fashion. The aim of this article is to highlight and compare the relative prevalence of NMS among patients with atypical parkinsonian syndromes in the published literature, which largely remain underreported and unaddressed in routine clinical practice. All NMS that are recognised to occur in PD are also found to commonly occur in atypical parkinsonian syndromes. In particular, excessive daytime sleepiness is more prevalent among atypical parkinsonian syndromes (94.3%) compared to PD (33.9%) or normal controls (10.5%) (p < 0.001). Urinary dysfunction (not limited to urinary incontinence) is not only found to occur in MSA (79.7%) and PD (79.9%), but has also been reported in nearly half of the patients with PSP (49.3%), DLB (42%) and CBD (53.8%) (p < 0.001). Apathy is significantly more common among the atypical parkinsonian syndromes [PSP (56%), MSA (48%), DLB (44%), CBD (43%)] compared to PD (35%) (p = 0.029). Early recognition and addressing of NMS among atypical parkinsonian syndromes may help improve the holistic patient care provided and may encompass a range of conservative and pharmacotherapeutic treatments to address these symptoms.

Vitamin A and vitamin D3 protect the visual apparatus during the development of dopamine-2 receptor knockout mouse model of Parkinsonism.

OBJECTIVES: Dopamine-related movement disorders are associated with a loss of visual acuity. Studies have shown that chemical stimulation of the vitamin D3 receptor (VDR) ameliorates movement disorders; however, the chemical stimulation is not effective when there is a deficiency of vitamin A in the cells. In the study, we examine the role of VDR and its interplay with vitamin A in impaired visual function in the dopamine deficit model. METHODS: Thirty (30) male mice with an average weight of 26 g ± (2) were divided into six group (NS,-D2,-D2 + VD D2 + VD, -D2 + VA, -D2 + (VD + VA) and -D2 + D2 groups). Dopamine deficit models of movement disorders were created using 15 mg/kg of haloperidol (-D2) injected intraperitoneally daily for 21 days. In the -D2 + (VD + VA) group, 800 IU/day of vitamin D3 (VD) and 1000 IU/day of vitamin A were concurrently used, while in the -D2 + D2 group, bromocriptine (+D2) was used as the standard treatment of the model. At the end of the treatment phase, the animals were subjected to visual water box test for visual acuity. The level of oxidative stress was measured using Superoxide dismutase (SOD) and malondialdehyde (MDA) in the retina and visual cortex. The level of cytotoxicity in these tissues was measured using Lactate dehydrogenase (LDH) assay, while the structural integrity of these tissues was assessed using a light microscope by assessing slide mounted sections that were stained with haematoxylin and eosin. RESULTS: A significant decline in time taken to reach the escape platform in the visual water box test was observed in the -D2 (p<0.005) and -D2 + D2 (p<0.05) group. In the retina and the visual cortex, a significant increase in LDH, MDA and the density of degenerating neurons was observed in the -D2 and -D2 + D2 groups. LDH level in the retina was also found to be significantly increased in (-D2 + VD, -D2 + VA, -D2 + (VD + VA). A Significant decrease in SOD was found in the retina and visual cortex of -D2 and -D2 + D2 group. In the histology of the retina, thinning of the retina, retinal fold, distortion and retinal detachment were all seen in the -D2 group. These structural alterations were not seen in other groups. Histological hallmarks of degeneration were observed in the visual cortex of the mice from the -D2 (p<0.001), -D2 + D2 (p<0.005) and -D2 + VD (p<0.05) groups only. CONCLUSIONS: Dopamine-deficient models of movement disorders are associated with loss of visual functions, especially due to thinning of the retina, retinal fold, retinal detachment, and neurodegeneration in the visual cortex. Supplementation during the development of the model with vitamin D3 and vitamin A prevented the deterioration of the retina and visual cortex by reducing the degree of oxidative stress and cytotoxicity.

Ameliorating parkinsonian motor dysfunction by targeting histamine receptors in entopeduncular nucleus-thalamus circuitry.

In Parkinson's disease (PD), reduced dopamine levels in the basal ganglia have been associated with altered neuronal firing and motor dysfunction. It remains unclear whether the altered firing rate or pattern of basal ganglia neurons leads to parkinsonism-associated motor dysfunction. In the present study, we show that increased histaminergic innervation of the entopeduncular nucleus (EPN) in the mouse model of PD leads to activation of EPN parvalbumin (PV) neurons projecting to the thalamic motor nucleus via hyperpolarization-activated cyclic nucleotide-gated (HCN) channels coupled to postsynaptic H2R. Simultaneously, this effect is negatively regulated by presynaptic H3R activation in subthalamic nucleus (STN) glutamatergic neurons projecting to the EPN. Notably, the activation of both types of receptors ameliorates parkinsonism-associated motor dysfunction. Pharmacological activation of H2R or genetic upregulation of HCN2 in EPNPV neurons, which reduce neuronal burst firing, ameliorates parkinsonism-associated motor dysfunction independent of changes in the neuronal firing rate. In addition, optogenetic inhibition of EPNPV neurons and pharmacological activation or genetic upregulation of H3R in EPN-projecting STNGlu neurons ameliorate parkinsonism-associated motor dysfunction by reducing the firing rate rather than altering the firing pattern of EPNPV neurons. Thus, although a reduced firing rate and more regular firing pattern of EPNPV neurons correlate with amelioration in parkinsonism-associated motor dysfunction, the firing pattern appears to be more critical in this context. These results also confirm that targeting H2R and its downstream HCN2 channel in EPNPV neurons and H3R in EPN-projecting STNGlu neurons may represent potential therapeutic strategies for the clinical treatment of parkinsonism-associated motor dysfunction.

Group physiotherapy and quality of life in parkinsonism: quasi-experimental study

According to systematic reviews, a short-term treatment of aquatic physiotherapy, mind-body therapies and exergame improve quality of life of people with parkinsonism. But few studies examined the group physiotherapy effects on quality of life of people with parkinsonism. Objective: We aimed to investigate the short-term effects of group physiotherapy protocols on the quality of life of people with Parkinson's disease or secondary parkinsonism. Methods: This is a quasi-experimental study, a controlled, non-randomized, unmasked trial, with consecutive arms for one group and parallel to another, with 15 participants with parkinsonism. They were organized in 3 groups: OG-E1wI (n = 9), observed group treated with group physiotherapy once a week; EG-C (n = 6), in the control phase without treatment, concomitant with OG-E1wI; EG-2wI (n = 6), the same subjects as EG-C, they were treated with group physiotherapy twice a week, in a posterior consecutive phase. The PDQ-39 scale was used to assess Quality of Life. Results: The mean differences between OG-E1wI and EG-C and between EG-2wI and EG-C in the various domains of PDQ-39 were not statistically significant. Conclusion: A group physiotherapy protocols performed once or twice a week may not be enough to improve quality of life for people with parkinsonism. The literature suggests that group physiotherapy protocols performed three to five times a week improve quality of life in a short period

Contexto: Revisões sistemáticas sugerem que fisioterapia aquática, terapias corporais complementares e exergame aumentam a qualidade de vida da pessoa com parkinsonismo em tratamento de curto prazo. Porém, os efeitos da fisioterapia em grupo na qualidade de vida da pessoa com parkinsonismo são pouco estudados. Objetivo: Investigar os efeitos em curto prazo de protocolos de fisioterapia grupal sobre a Qualidade de Vida de pessoas com doença de Parkinson e parkinsonismo secundário. Métodos: Estudo quasi-experimental, ensaio controlado não randomizado, sem mascaramento, com braços consecutivos para um grupo e paralelo para outro, com 15 participantes com parkinsonismo. Os participantes foram organizados em 3 grupos: OG-E1wI (n= 9), intervenção de fisioterapia em grupo uma vez por semana; EG-C (n= 6), em fase controle sem tratamento, concomitante ao OG-E1wI; EG-2wI (n=6), os mesmos sujeitos do EG-C, em fase consecutiva com intervenção de fisioterapia em grupo, duas vezes por semana. A escala PDQ-39 foi utilizada para avaliar a Qualidade de Vida. Resultados: As diferenças médias entre OG-E1wI e EG-C e entre EG-2wI e EG-C nos vários domínios da PDQ-39 não são estatisticamente significativas. Conclusão: Protocolos de fisioterapia em grupo com frequência de uma ou duas vezes por semana podem não ser suficiente para promover ganhos na qualidade de vida de pessoas com parkinsonismo. A literatura sugere que protocolos de fisioterapia em grupo feitos três a cinco vezes por semana obtêm ganho de qualidade de vida em um período de curto prazo

A Prospective Study on the Relationship between Iron Supplement Intake, Hemoglobin Concentration, and Risk of Parkinsonism.

The findings regarding whether the greater iron level or intake is a risk factor to Parkinson's disease (PD) or parkinsonism was not clear. The purpose of this study is to establish a consistent association between iron supplementation and parkinsonism risk, we conducted a large-scale prospective cohort study using comprehensive longitudinal data from the UK Biobank. The longitudinal cohort data of 385,898 participants (including 911 cases) who were middle to old aged British adults and joined the UK Biobank study from 2006 to 2010 and were followed up until 2018 was analyzed. The associations between iron supplement intake, hemoglobin levels and all cause subsequent parkinsonism risk after corrections of potential confounders (sex, age, household income, education length, employment status, deprivation level, body mass index, physical activity level, household numbers, smoking and drinking levels, health status, blood pressure) were investigated. Analyses revealed that (a) iron supplementation was significantly associated with higher parkinsonism risk, (b) greater hemoglobin was weakly and insignificantly associated with lower parkinsonism risk, and (c) multivitamin or vitamin C supplement intake was not significantly associated with parkinsonism risk. Regardless of whether the subjects were classified as anemic, normal, or polycythemic or in the hemoglobin level quintile, there was no nonlinear association between hemoglobin and parkinsonism risk. Parkinsonism risk did not differ between participants reporting supplementary iron intake with or without vitamin C or multivitamin supplement intake. Furthermore, polygenic risk score of PD negatively correlated with hemoglobin level, while it did not associate with intake of iron supplement or multivitamin or vitamin C supplement intake. The results suggest excessive iron intake may increase parkinsonism risk. Interventional studies are warranted to examine whether iron intake restriction is beneficial for individuals without clinical iron deficiency.

Annonaceae Consumption Worsens Disease Severity and Cognitive Deficits in Degenerative Parkinsonism.

BACKGROUND: High consumption of Annona muricata fruit has been previously identified as a risk factor for atypical parkinsonism in the French Caribbean islands. OBJECTIVE: We tested whether consumption of Annonaceae products could worsen the clinical phenotype of patients with any form of degenerative parkinsonism. METHODS: We analyzed neurological data from 180 Caribbean parkinsonian patients and specifically looked for dose effects of lifelong, cumulative Annonaceae consumption on cognitive performance. Using unsupervised clustering, we identified one cluster with mild/moderate symptoms (N = 102) and one with severe symptoms including cognitive impairment (N = 78). RESULTS: We showed that even low cumulative consumption of fruits/juices (>0.2 fruit-years) or any consumption of herbal tea from Annonaceae worsen disease severity and cognitive deficits in degenerative parkinsonism including Parkinson's disease (OR fruits-juices: 3.76 [95% CI: 1.13-15.18]; OR herbal tea: 2.91 [95% CI: 1.34-6.56]). CONCLUSION: We suggest that more restrictive public health preventive recommendations should be made regarding the consumption of Annonaceae products. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A GLP1 receptor agonist diabetes drug ameliorates neurodegeneration in a mouse model of infantile neurometabolic disease.

Infantile neuroaxonal dystrophy (INAD) is a rare paediatric neurodegenerative condition caused by mutations in the PLA2G6 gene, which is also the causative gene for PARK14-linked young adult-onset dystonia parkinsonism. INAD patients usually die within their first decade of life, and there are currently no effective treatments available. GLP1 receptor (GLP-1R) agonists are licensed for treating type 2 diabetes mellitus but have also demonstrated neuroprotective properties in a clinical trial for Parkinson's disease. Therefore, we evaluated the therapeutic efficacy of a new recently licensed GLP-1R agonist diabetes drug in a mouse model of INAD. Systemically administered high-dose semaglutide delivered weekly to juvenile INAD mice improved locomotor function and extended the lifespan. An investigation into the mechanisms underlying these therapeutic effects revealed that semaglutide significantly increased levels of key neuroprotective molecules while decreasing those involved in pro-neurodegenerative pathways. The expression of mediators in both the apoptotic and necroptotic pathways were also significantly reduced in semaglutide treated mice. A reduction of neuronal loss and neuroinflammation was observed. Finally, there was no obvious inflammatory response in wild-type mice associated with the repeated high doses of semaglutide used in this study.

Lippia grata essential oil complexed with ß-cyclodextrin ameliorates biochemical and behavioral deficits in an animal model of progressive parkinsonism.

Parkinson's disease (PD) is identified by the loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNpc), and is correlated to aggregates of proteins such as α-synuclein, Lewy's bodies. Although the PD etiology remains poorly understood, evidence suggests a main role of oxidative stress on this process. Lippia grata Schauer, known as "alecrim-do-mato", "alecrim-de-vaqueiro", "alecrim-da-chapada", is a native bush from tropical areas mainly distributed throughout the Central and South America. This plant species is commonly used in traditional medicine for relief of pain and inflammation conditions, and that has proven antioxidant effects. We evaluated the effects of essential oil of the L. grata after its complexed with ß-cyclodextrin (LIP) on PD animal model induced by reserpine (RES). Behavioral assessments were performed across the treatment. Upon completion the treatment, the animals were euthanized, afterwards their brains were isolated and processed for immunohistochemical and oxidative stress analysis. The LIP treatment delayed the onset of the behavior of catalepsy, decreased the number of oral movements and prevented the memory impairment on the novel object recognition task. In addition, the treatment with LIP protected against dopaminergic depletion in the SNpc and dorsal striatum (STRd), and decreased the α-syn immunoreactivity in the SNpc and hippocampus (HIP). Moreover, there was reduction of the oxidative stability index. These findings demonstrated that the LIP treatment has neuroprotective effect in a progressive parkinsonism model, suggesting that LIP could be an important source for novel treatment approaches in PD.

Sesquiterpenoids isolated from davana (Artemisia pallens Wall. ex DC) mitigates parkinsonism in Caenorhabditis elegans disease model.

Parkinson's disease (PD) is a multifactorial ailment that severely affects the viability of dopaminergic neurons leading to progressive loss of motor control. The current regimen for PD treatment includes synthetic drugs that lack efficacy and cause serious side effects. Consequently, recent drug development studies are focusing on alternative medicines from plant sources. Artemisia pallens Wall. ex DC, commonly known as davana, is an annual aromatic herb cultivated in southern India. Given the diverse traditional and scientifically documented therapeutic effects of A. pallens, the pharmacological potential of the isolates of the plant, namely bicyclogermacrene (D1), cis-davanone (D3), and cis-hydroxy davanone (D5), was tested for anti-Parkinson's activity in Caenorhabditis elegans model. The tested compounds alleviated α-synuclein (α-syn) aggregation and maximum decline was observed in 25 µM D1 supplemented worms. Additionally, D1 modulated dopamine regulated nonanol-1 repulsion and locomotory behaviour of C. elegans validating its future use as a dopamine-enhancing agent. The genetic regulation mediating the above effects validated through the qPCR study showed that D1 supplementation displayed its anti-Parkinson's effect through upregulation of the antioxidant defence system genes (superoxide dismutase (sod)-1, sod-2, and sod-4) and PD associated pdr-1 gene that maintains the mitochondrial proteostasis. The molecular docking studies of C. elegans PDR-1 with D1 further confirmed its contribution in D1 induced abridgment of Parkinson disease linked pathologies in C. elegans disease model. Hence, this article proposes D1 as an effective regimen for curtailing the Parkinson disease linked pathologies through mechanism of maintaining cellular redox state and proteostasis.

Demethylenetetrahydroberberine protects dopaminergic neurons in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is a multifactorial disorder of the nervous system where a progressive loss of dopaminergic neurons exist. However, the pathogenesis of PD remains undefined, which becomes the main limitation for the development of clinical PD treatment. Demethylenetetrahydroberberine (DMTHB) is a novel derivative of natural product berberine. This study was aimed to explore the neuroprotective effects and pharmacological mechanism of DMTHB on Parkinson's disease using C57BL/6 mice. A PD model of mice was induced by administration of MPTP (20 mg·kg-1) and probenecid (200 mg·kg-1) twice per week for five weeks. The mice were administered with DMTHB daily by gavage at the dose of 5 and 50 mg·kg-1 for one- week prophylactic treatment and five-week theraputic treatment. The therapeutic effects of DMTHB were evaluated by behavior tests (the open field, rotarod and pole tests), immunohistochemical staining of tyrosine hydroxylase (TH), Nissl staining and biochemical assays. The molecular mechanisms of DMTHB on the key biomarkers of PD pathological states were analyzed by Western blot (WB) and qRT-PCR. DMTHB treatment alleviated the behavioral disorder induced by MPTP-probenecid. Nissl staining and TH staining showed that the damage of dopaminergic neurons in the substantia nigra was remarkably suppressed by DMTHB treatment. Western blot results showed that the ratio of Bcl-2/Bax and TH increased, but the level of α-synuclein (α-syn) was remarkably reduced, which indicated that the apoptosis of dopaminergic neurons in mice was significantly reduced. The protein phosphorylation of p-PI3K, p-AKT and p-mTOR also increased about 2-fold, compared with the model group. Furthermore, qRT-PCR results demonstrated that the mRNA levels of pro-inflammatory cytokines, IL-1ß and TNF-α, were reduced, but the level of anti-inflammatory cytokine IL-10 increased after DMTHB treatment. Finally, the cellular assay displayed that DMTHB was also a strong antioxidant to protect neuron cell line PC12 by scavenging ROS. In this study, we demonstrated DMTHB alleviates the behavioral disorder and protects dopaminergic neurons through multiple-target effects includubg anti-apoptotic, anti-inflammatory and antioxidant effects.

Decreased thalamic monoamine availability in drug-induced parkinsonism.

Drug-induced parkinsonism (DIP) is caused by a dopamine receptor blockade and is a major cause of misleading diagnosis of Parkinson's disease (PD). Striatal dopamine activity has been investigated widely in DIP; however, most studies with dopamine transporter imaging have focused on the clinical characteristics and prognosis. This study investigated differences in striatal subregional monoamine availability among patients with DIP, normal controls, and patients with early PD. Thirty-five DIP patients, the same number of age-matched PD patients, and 46 healthy controls were selected for this study. Parkinsonian motor status was examined. Brain magnetic resonance imaging and positron emission tomography with 18F-N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane were performed, and the regional standardized uptake values were analyzed with a volume-of-interest template and compared among the groups. The groups were evenly matched for age, but there were numerically more females in the DIP group. Parkinsonian motor symptoms were similar in the DIP and PD groups. Monoamine availability in the thalamus of the DIP group was lower than that of the normal controls and similar to that of the PD group. In other subregions (putamen, globus pallidus, and ventral striatum), monoamine availability in the DIP group and normal controls did not differ and was higher than that in the PD group. This difference compared to healthy subject suggests that low monoamine availability in the thalamus could be an imaging biomarker of DIP.

Striatal synaptic bioenergetic and autophagic decline in premotor experimental parkinsonism.

Synaptic impairment might precede neuronal degeneration in Parkinson's disease. However, the intimate mechanisms altering synaptic function by the accumulation of presynaptic α-synuclein in striatal dopaminergic terminals before dopaminergic death occurs, have not been elucidated. Our aim is to unravel the sequence of synaptic functional and structural changes preceding symptomatic dopaminergic cell death. As such, we evaluated the temporal sequence of functional and structural changes at striatal synapses before parkinsonian motor features appear in a rat model of progressive dopaminergic death induced by overexpression of the human mutated A53T α-synuclein in the substantia nigra pars compacta, a protein transported to these synapses. Sequential window acquisition of all theoretical mass spectra proteomics identified deregulated proteins involved first in energy metabolism and later, in vesicle cycling and autophagy. After protein deregulation and when α-synuclein accumulated at striatal synapses, alterations to mitochondrial bioenergetics were observed using a Seahorse XF96 analyser. Sustained dysfunctional mitochondrial bioenergetics was followed by a decrease in the number of dopaminergic terminals, morphological and ultrastructural alterations, and an abnormal accumulation of autophagic/endocytic vesicles inside the remaining dopaminergic fibres was evident by electron microscopy. The total mitochondrial population remained unchanged whereas the number of ultrastructurally damaged mitochondria increases as the pathological process evolved. We also observed ultrastructural signs of plasticity within glutamatergic synapses before the expression of motor abnormalities, such as a reduction in axospinous synapses and an increase in perforated postsynaptic densities. Overall, we found that a synaptic energetic failure and accumulation of dysfunctional organelles occur sequentially at the dopaminergic terminals as the earliest events preceding structural changes and cell death. We also identify key proteins involved in these earliest functional abnormalities that may be modulated and serve as therapeutic targets to counterbalance the degeneration of dopaminergic cells to delay or prevent the development of Parkinson's disease.

Pycnogenol ameliorates motor function and gene expressions of NF-ƙB and Nrf2 in a 6-hydroxydopamine-induced experimental model of Parkinson's disease in male NMRI mice.

We investigated the effect of Pycnogenol as an antioxidant on improving motor function, depression, and the expression of NF-ƙB and Nrf2 genes in the experimental model of Parkinson's disease. Forty adult male NMRI mice weighing about 30 g were randomly divided into five groups of eight. Saline group: received 3 µl of saline, as 6-hydroxydopamine (6-OHDA) solvent, unilaterally in the left striatum, treatment groups: first received 3 µl 6-OHDA unilaterally inside the ipsilateral striatum and then divided into subgroup A: received distilled water, Pycnogenol solvent, by gavage for 7 days (lesion group), and subgroup B: received Pycnogenol at doses of 10, 20, and 30 mg/kg by gavage for 7 days. Seven days after Parkinson's model induction, the apomorphine test, the degree of catalepsy by bar test, the duration of immobility (depression) by forced swimming test (FST) were measured. In addition, the expression of NF-ƙB and Nrf2 genes was measured using the real-time PCR technique. The total number of rotations in the apomorphine test decreased significantly in the groups receiving Pycnogenol. Administration of Pycnogenol significantly reduced catalepsy. The study of depression in the group receiving Pycnogenol showed a significant reduction. Also, Pycnogenol increased the expression of the Nrf2 anti-inflammatory gene, but it had no significant difference in the expression of NF-ƙB gene. Pycnogenol, presumably with its antioxidative and genomic effects, improves the expression of the anti-inflammatory gene and found that neuroprotection effect in the brain.

Beneficial effects of an algal oil rich in ω-3 polyunsaturated fatty acids on locomotor function and D2 dopamine receptor in haloperidol-induced parkinsonism.

INTRODUCTION: Parkinson's disease (PD) is a chronic neurological disorder whose pathogenesis involves the loss of dopaminergic neurons and dopamine terminals, formation of Lewy bodies, and microgliosis. Its treatment includes dopamine-based drugs with limited results and adverse effects. Additionally, some neuroleptic drugs used for mental disorders produce side effects referred to as parkinsonism. Dietary interventions with ω-3 polyunsaturated fatty acids (ω-3 PUFA) have attracted attention since they play a key role in most of the processes associated with PD etiology. OBJECTIVE: The purpose of our work was to investigate the effects of an ω-3 PUFA rich algal oil on locomotive alterations induced by haloperidol and D2 receptor protein and gene expression in Wistar rats. METHODOLOGY: Pre- and co-supplementation of algal oil (300 mg of ω-3 FA/kg/day for six weeks) and haloperidol (1.5 mg/kg/day for two weeks) were evaluated. RESULTS: Haloperidol provoked locomotive alterations in the Open Field Test and a 43% diminution in D2 receptor in brain membranes; in pre-supplemented rats a 93% increase in D2 receptor protein expression and a partial maintenance of locomotory performance were observed, while in co-supplemented rats D2 receptor protein expression was maintained as in control rats, although locomotive behavior was found diminished as in haloperidol rats. CONCLUSIONS: These results confirm the beneficial effects of ω-3 PUFA over locomotory alterations and as neuroprotective and neurorestorative compounds and demonstrates a stimulatory action on D2 receptor presence, as a mechanism by which these fatty acids participate in brain health.