Journal of Neural Transmission最新文献

L-dopa-induced dyskinesia (LID) is an incapacitating complication of long-term administration of L-dopa therapy that commonly affects patients with Parkinson's disease (PD) due to the widespread use of the causative drug. Herein, we investigated the therapeutic potential of sitagliptin, a drug used to treat type 2 diabetes mellitus, to treat LID. 6-hydroxydopamine (6-OHDA) was unilaterally injected into the left side of the substantia nigra pas compacta to induce a mouse model of PD. After four weeks of 6-OHDA induction, L-dopa was administered with or without sitagliptin for 11 consecutive days. LID was monitored using abnormal involuntary movement (AIM) scoring, conducted on days 5 and 10 of L-dopa treatment. Comparative proteomic analysis was performed on the 6-OHDA-lesioned striatum by comparing groups treated with vehicle + L-dopa and sitagliptin + L-dopa. Sitagliptin combined with L-dopa significantly attenuated AIM scores in 6-OHDA-lesioned mice. Proteomic analysis following sitagliptin treatment showed an increase in proteins involved in mitochondrial function regulation and a decrease in proteins associated with cytoskeleton function regulation. Changes in the expression of Ndufb2, a subunit of NADH: ubiquinone oxidoreductase (complex I), and Arc, an immediate early gene (IEG), which showed the most significant increase and decrease, respectively, were validated using western blotting and RT-PCR analysis. These findings suggest that sitagliptin may have therapeutic potential by enhancing mitochondrial functions and suppressing neuronal activity in the striatum, thereby mitigating the incapacitating complications associated with long-term L-dopa use in patients with PD.

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra (SN) and abnormal iron metabolism. While most of the current studies have focused on nigral iron deposition, there is still limited research into the role of iron in other brain regions. The zona incerta (ZI) is a heterogeneous subthalamic region and has extensive connections with the basal ganglia nucleus. Clinically, the ZI has been recognized as a new therapeutic target for PD. Deep brain stimulation of the ZI has been reported to relieve motor symptoms and experimental heat pain in patients with PD. The aim of the present study is to evaluate changes in iron levels in the ZI. Two neurotoxins, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA), were used to prepare PD mice. By immunostaining, we first measured the success of MPTP or 6-OHDA injury. We found that the expressions of tyrosine hydroxylase were decreased after MPTP or 6-OHDA treatment. Secondly, we observed the changes of iron metabolism using Perls' iron staining and western blots. Our results showed that the numbers of iron-positive cells were significantly increased in the SN and ZI of MPTP/6-OHDA-treated mice. Moreover, the expression levels of ferritin and divalent metal transporter 1 (DMT1) in the ZI were also increased in the PD group. Glutathione peroxidase 4 (GPX4), a marker of ferroptosis, was also detected. Western blots revealed that MPTP significantly down-regulated the level of GPX4 in the ZI. As glial cells activation and neuroinflammation play important roles in the ion deposition, we finally investigated the microglial and astrocyte activation and inflammatory factors. These results suggested increased iron levels and inflammation may be present in the ZI in PD mice.

Schizophrenia spectrum disorders (SSD) are a complex group of illnesses, and their pathophysiology remains unclear. Recent developments in neuroimaging techniques provided useful quantitative measures, such as quantitative T1 mapping (qT1) that is susceptible to tissue-level, microscopic changes. However, it is important to identify the most sensitive, accurate, and reliable imaging protocol, given the complex nature of SSD. We compared structural brain changes in a pilot sample of 15 SSD patients and 7 healthy controls, cross-sectionally, and using two different qT1 mapping protocols. Our findings showed a global elevation in qT1 values in SSD patients, that was statistically significant in the lateral ventricles, thalamus, caudate, and hippocampus (p < 0.01). Moreover, the two acquisition protocols were differently modulated by demographic factors, such as age, sex, and education, which further illustrates the importance of protocol selection. In conclusion, this investigation revealed microstructural tissue changes in subcortical regions in SSD patients, providing further insights into the pathophysiology of the illness.

Formononetin [FMN] belongs to the member of class 7-hydroxyisoflavones possesses anti-oxidant and anti-inflammatory activity. However, its efficacy in chronic unpredictable stress (CUS) associated with Parkinson disease (PD) is not evaluated. In a current study the effect of FMN on CUS associated with PD was screened to examine efficacy using different behavioral, biochemical and immuno-histochemical evaluation. During the study, CUS associated with PD was induced in mice by administering rotenone followed by exposure to different mild stressors. Animals showing CUS linked to PD were included in the study and treated daily with FMN (5, 10 & 20 mg/kg) by intraperitoneal route. After the treatment, animals evaluated for behavioral, biochemical parameters and immunohistochemistry analysis. Treatment with FMN was effective in alleviating core symptoms of chronic stress linked to PD and improved cognitive function, gait abnormality and impairment in co-ordination of CUS + ROT model. FMN showed dose dependent reduction in IL- 1β, TNF- α, IL- 6 concentration. FMN increasing the levels of dopamine, norepinephrine and serotonin. Immunohistochemical study revealed that the expression of α-synuclein reduced which helps to improve CUS linked to Parkinson's. Furthermore, expression of BDNF and BCL-2 found to be improved after FMN treatment and helps in elevation of dopamine levels thereby surviving neuronal system. Study findings revealed that formononetin is effective in the treatment of chronic unpredictable stress linked to Parkinson's, however further clinical investigation is required to evaluate its effect in human.

To investigate the clinical impact of mild behavioral impairment (MBI) in a predefined cohort with Lewy body disease (LBD) continuum. Eighty-four patients in the LBD continuum participated in this study, including 35 patients with video-polysomnography-confirmed idiopathic REM sleep behavior disorder (iRBD) and 49 clinically established LBD. Evaluations included the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), neuropsychological tests, and MBI Checklist (MBI-C). We examined the clinical associates of MBI-C and its diagnostic values in predicting disease severity and cognitive impairment across the LBD continuum. Participants were classified into 19 cognitively normal (CN), 45 mild cognitive impairment (MCI), and 20 dementia groups. Median MBI-C total scores were 1.0, 8.0, and 18.5 for CN, MCI, and dementia groups, respectively, with a significant increasing trend (p < 0.001). The MBI-C total score demonstrated significant correlations with the MDS-UPDRS part 1 (r = 0.504, p < 0.001) and total scores (r = 0.508, p < 0.001). Furthermore, significant correlations were observed between MBI-C and cognitive performances in frontal/executive (DSC: r = -0.314, p = 0.006; TMT-B: r = -0.338, p = 0.003) and attentional (TMT-A: r = -0.343, p = 0.002) domains. A cutoff 5.0 effectively differentiated the MCI from CN groups (area under the curve (AUC = 0.74). Furthermore, the MBI-C effectively discriminated the iRBD patients with high phenoconversion risk against those with low-risk (cut-off 4.0, AUC = 0.72). The MBI-C may be a useful screening questionnaire reflecting clinical severity across the LBD continuum. Longitudinal studies are needed to determine its value in monitoring disease progression in prodromal LBD.

Anhedonia is a core transnosographic symptom in several neuropsychiatric disorders. Recently, the Triple Network (TN) model has been proposed as a useful neurophysiological paradigm for conceptualizing anhedonia, providing new insights to clinicians and researchers. Despite this, the relationship between the functional dynamics of TN and the severity of anhedonia has been relatively understudied in non-clinical samples, especially in the resting state (RS) condition. Therefore, in the current study, we investigated this relationship using electroencephalography (EEG) functional connectivity. Eighty-two participants (36 males; mean age: 24.28 ± 7.35 years) underwent RS EEG recording with eyes-closed and completed the Beck Depression Inventory-derived 4-item anhedonia scale (BDI-Anh4) and the Brief Symptoms Inventory (BSI). EEG data on functional connectivity were analyzed using the exact low-resolution electromagnetic tomography (eLORETA). A significant positive correlation was observed between the BDI-Anh4 total score and salience-default mode network connectivity in the beta frequency band (r = 0.409; p = 0.010). The results of the hierarchical linear regression analysis also showed that this connectivity pattern was positively and independently associated (β = 0.358; p < 0.001) with the BDI-Anh4 total score and explained an additional 11% of the anhedonia variability. The association between anhedonia severity and increased salience-default mode network synchronization detected in the current study may reflect difficulty disengaging from internal/self-related mental contents, which consequently impairs the processing of other stimuli, including rewarding stimuli.

Joubert Syndrome (JS) is a congenital cerebellar ataxia typically inherited in an autosomal recessive pattern, although rare X-linked inheritance can occur. It is characterized by hypotonia evolving into ataxia, global developmental delay, oculomotor apraxia, breathing dysregulation, and multiorgan involvement. To date, there are 40 causative genes implicated in JS, all of which encode proteins of the primary cilium. Primary cilia play a crucial role in the normal development and function of many organs, including parts of the brain (cerebellum and brainstem), kidneys, and the retina. This likely explains the multiorgan involvement seen in JS. In this report, we present the first genetically confirmed case of JS in two Filipino adolescent siblings who had early onset ataxia, hepatomegaly, and global developmental delay. A cranial CT scan revealed the Molar Tooth Sign (MTS). Whole Exome Sequencing (WES), performed via buccal swab, showed biallelic pathogenic variants at NM_153704.6:c.2086 C > T (NP_714915.3:p.Leu696Phe) and NM_153704.6:c.431del (NP_714915.3:p.Leu144CysfsTer19) in TMEM67, which are associated with Joubert Syndrome 6 (OMIM:610688) in a compound heterozygous state. The prevalence of NM_153704.6:c.2086 C > T (NP_714915.3:p.Leu696Phe) in TMEM67 variant is very rare (< 0.001%), and the NM_153704.6:c.431del (NP_714915.3:p.Leu144CysfsTer19) has not been recorded. This case contributes valuable information to the expanding knowledge of JS and its related disorders.

Aneurysmal subarachnoid hemorrhage (aSAH) is a debilitating condition with significant morbidity and mortality rates. Despite advancements in treatment, understanding the underlying pathophysiology, particularly the inflammatory response, remains crucial for improving patient outcomes. In this study, we investigated the presence of transmembrane protein 119 (TMEM119) of microglial cells in cerebrospinal fluid (CSF) as a potential marker for neuroinflammation following aSAH. CSF samples were collected from aSAH patients, pathological and healthy controls, processed, and analyzed using immunocytochemistry. TMEM119-positive microglial cells were consistently identified in the CSF of aSAH patients, exhibiting amoeboid morphology and intense staining. Importantly, microglial cells were detected as early as the first day post-bleeding, persisting throughout the acute phase in some cases. Analysis of consecutive samples revealed varying trends in microglial cell numbers, with a peak during the initial phase followed by a gradual decline. Our findings suggest that microglia may migrate into the CSF following aSAH, potentially serving as an early predictor of inflammatory-related CNS damage. This study underscores the importance of understanding neuroinflammatory processes in aSAH and opens avenues for further research on the role of microglia in CNS disorders by liquid biopsy.

Huntington's disease (HD) is characterized by a combination of motor, cognitive, and neuropsychiatric impairments. Among them, impulsivity and attention deficits are clinical features usually described in HD, impacting the quality of life of patients and their caregivers. Twenty early-stage HD patients (PHD) and 20 age and gender-matched control participants (CP) performed a "Simon" reaction time (RT) task allowing us to explore action impulsivity and attention deficits. Surface EMG recordings aimed at revealing the presence and characterizing the nature of impulsivity in PHD. Correlational analyses between error rates or chronometric data, and clinical or neuropsychological data were examined. (1) Analysis of the accuracy and EMG patterns revealed no difference between PHD and CP, indicating absence of motor impulsivity at the early stage of HD. (2) Chronometric indices revealed a general slowing of information processing in PHD, involving central information processing but sparing the latest stages of motor execution, consistent with performed correlational analysis. (3) Sequential analysis of RT patterns showed a failure to allocate attention appropriately. These indices of attentional deficits nicely correlated with performance in neuropsychological tests exploring attentional processes. (1) Central information processing slows down at the early stage of HD but the latest steps of motor execution are unaffected. (2) In the progression of HD, attentional deficits typically should appear first among dysexecutive problems, without significant action impulsivity.

Parkinson's disease (PD) is a chronic neurodegenerative disease of the elderly. Patients suffer from progressive motor and non-motor symptoms. Further, PD patients often present geriatric features like multimorbidity and polypharmacotherapy. A frequent comorbidity of PD patients is diabetes mellitus type two (T2DM). In the last decade growing evidence emerged on the impact of T2DM on PD. Of the present review was to analyze the impact of T2DM on PD incidence and progression in patient cohorts. A systematic review of the literature was performed via PubMed and Google Scholar. Studies on longitudinal PD patient cohorts with at least 10 patients per group were included. The diabetic state of the patient had to be determined. In total, 15 studies were analyzed for this review. According to most of the included studies T2DM increases the risk of developing PD significantly. Disease progression is augmented by T2DM both for motor and cognitive impairments. Some studies also point out a correlation of motor worsening and diabetic status measured by the serum HbA1c level. In relation to biomarkers, PD patients with diabetes have higher neurofilament light chain and Tau level but lower Amyloid beta level. T2DM seems to be a risk factor for the development and progression of PD. PD patients should be screened for T2DM and treatment should be initiated promptly. There is still a lack of knowledge about the molecular mechanisms leading to interactions of these diseases.