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Depression is a highly prevalent and debilitating non-motor symptom observed during the early stages of Parkinson’s disease (PD). Although PD prevalence is higher in men, the depressive symptoms in PD are more common in women. Therefore, the aim of this study was to investigate the development of anhedonic- and depressive-like behaviors in male and female mice and the potential mechanisms related to depressive symptoms in an experimental model of PD. Young adult male and female C57BL/6 mice (3 months old) received a single intranasal (i.n.) administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and were submitted to a battery of behavioral tasks (sucrose consumption, splash test, tail suspension, forced swimming and open field tests) to assess their emotional and motor profiles. Considering the role of sexual hormones in emotional behaviors, the same protocol of i.n. MPTP administration and the splash, tail suspension, and open field tests were conducted in ovariectomized (OVX) and aged C57BL/6 female (20 months old) mice. We also investigated the immunocontent of neurotrophins (BDNF, GDNF, and VEGF) in the hippocampus and prefrontal cortex by western blot. I.n.  MPTP administration induced more pronounced anhedonic- and selective depressive-like behaviors in female adult mice, also observed in OVX and aged female mice, with the absence of motor impairments. Furthermore, MPTP induced a more pronounced depletion of neurotrophins in the prefrontal cortex and hippocampus in female than male mice. This study provides new evidence of increased susceptibility of female mice to anhedonic- and depressive-like behaviors following i.n. MPTP administration. The observed gender-related effects of MPTP on emotional parameters seem to be linked to increased depletion of neurotrophins (particularly BDNF and GDNF) in the hippocampus and prefrontal cortex of female mice. [ABSTRACT FROM AUTHOR]

Background The objective of this study was to compare the incidence and prevalence of depressive symptoms in atypical parkinsonian ( APD) syndromes versus Parkinson disease ( PD). Methods In a large, retrospective patient cohort, the authors analyzed the incidence and prevalence of depressive symptoms using the Beck Depression Inventory and evaluated patients longitudinally on subsequent visits. For individuals who were followed at subsequent visits, incidence rates were calculated in person-years as a measure of incidence. Results In total, 361 patients were identified who had APD syndromes, including progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy, and dementia with Lewy bodies; and 2352 patients with PD were used as a control group. The mean Beck Depression Inventory values were significantly higher in patients with APD (F = 14.19; P < 0.001). A significantly higher proportion of those with APD screened positive for depressive symptoms both at the initial visit and on subsequent visits ( P < 0.001), and depressive symptoms appeared to be more severe in the APD subgroups. Unified Parkinson's Disease Rating Scale motor scores and disease duration were correlated with depressive symptoms. Conclusions The current results suggest that the incidence and prevalence of depressive symptoms are higher in patients with APD syndromes and also appear to be more severe than those in patients with PD. Depressive symptoms in APD are common and affect patients regardless of disease duration or motor severity. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) patients have an increased risk of falls resulting in important social and economical consequences. Risk factors for falls include the use of psychotropic drugs, which are used for the treatment of PD neuropsychiatric symptoms. We aimed to determine the association between psychotropic drug use and falls in a PD cohort. A cross-sectional study from the NPF QII study UF site was conducted. Subjects reported presence and frequency of falls in the prior year. Frequency was scored from 0 (no falls) to 4 (falling daily). Antidepressants, antipsychotics, cognitive enhancers/stimulants, and benzodiazepines were considered psychotropics. Forty percent of the 647 subjects included had a fall in the previous year. Fallers were found to have clinical signs of a more advanced disease. After adjusting for confounding variables, the regression analysis showed that use of antidepressants alone (adjusted OR 2.2, CI 95 % 1.3-3.8, p = 0.04), benzodiazepines alone (adjusted OR 2.0, CI 95 % 1.1-3.5, p = 0.02), and the combination of antidepressants with benzodiazepines (adjusted OR 4.1, CI 95 % 2.0-8.3, p < 0.0001) were independently associated with the presence of falls. When comparing to those not on psychotropics, subjects on antidepressants alone had a significantly higher mean frequency of falls score (1.07 vs. 0.44, p < 0.0001). The use of antidepressants was independently associated with falls in our PD cohort after considering for confounding variables such as age and measures of disease progression. Other factors related to disease progression should be considered before claiming the use of psychotropic drugs as causative. [ABSTRACT FROM AUTHOR]

Sleep disturbance is a common nonmotor phenomenon in Parkinson’s disease (PD) affecting patient’s quality of life. In this study, we examined the association between clinical characteristics with sleep disorders and sleep architecture patterns in a PD cohort. Patients underwent a standardized polysomnography study (PSG) in their “on medication” state. We observed that male gender and disease duration were independently associated with obstructive sleep apnea (OSA). Only lower levodopa equivalent dose (LED) was associated with periodic limb movement disorders (PLMD). REM sleep behavior disorder (RBD) was more common among older patients, with higher MDS-UPDRS III scores, and LED. None of the investigated variables were associated with the awakenings/arousals (A/A). Sleep efficiency was predicted by amantadine usage and age, while sleep stage 1 was predicted by dopamine agonists and Hoehn & Yahr severity. The use of MAO-B inhibitors and MDS-UPDRS part III were predictors of sleep stages 2 and 3. Age was the only predictor of REM sleep stage and gender for total sleep time. We conclude that sleep disorders and architecture are poorly predictable by clinical PD characteristics and other disease related factors must also be contributing to these sleep disturbances. [ABSTRACT FROM AUTHOR]

• Intranasal NaDMDC administration in mice induces motor impairments that lasts until 35 days. • Melatonin treatment protects against motor deficits induced by NaDMDC in early and late phases. • Melatonin reduces the oxidative/nitrosative damages induced by NaDMDC in brain structures of mice. • The dopaminergic nigrostriatal pathway was protect by melatonin treatment. Exposure to fungicide ziram (zinc dimethyldithiocarbamate) has been associated with increased incidence of Parkinson's disease (PD). We recently demonstrated that the intranasal (i.n.) administration of sodium dimethyldithiocarbamate (NaDMDC, a more soluble salt than ziram) induces PD-like behavioral and neurochemical alterations in mice. We now investigated the putative neuroprotective effects of melatonin on behavioral dificits and neurochemical alterations induced by i.n. NaDMDC. Melatonin treatment (3, 10 or 30 mg/kg, i.p.) was given 1 h before NaDMDC administration (1 mg/nostril) during 4 consecutive days and we evaluated early (up to 7 days) and late (up to 35 days) NaDMDC-induced behavioral and neurochemical alterations. Melatonin treatment protected against early motor and general neurological impairments observed in the open field and neurological score of severity, respectively, and late deficits in rotarod test. Melatonin prevented the NaDMDC-induced alterations in the striatal tyrosine hydroxylase immunocontent. Melatonin also protected against increased levels of oxidative stress markers (4-hydroxynonenal and 3-nitrotyrosine) in the striatum, as well as the NaDMDC-induced increase of 4-hydroxynonenal and TNF, markers of oxidative stress and inflammation, respectively, in the olfactory bulb. These results further detail the mechanisms underlying NaDMDC toxicity and demonstrate the neuroprotective effects of melatonin against the neuronal damage induced by NaDMDC. [ABSTRACT FROM AUTHOR]

Objective: Parkinson's disease (PD) is often accompanied by stigma, which could contribute to a worse prognosis. The objective of this study is to identify the variables associated with stigma in PD patients who are candidates for deep brain stimulation (DBS). Methods: We investigated sociodemographic and clinical variables associated with stigma in a sample of 54 PD patients indicated for DBS. The independent variables were motor symptoms assessed by the Movement Disorder Society-sponsored revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS III), depressive symptoms measured by the Hospital Anxiety and Depression Scale, age, disease duration and the presence of a general medical condition. The Mobility, Activities of daily living and Emotional well-being domains of the 39-item Parkinson's Disease Questionnaire (PDQ-39) were also investigated as independent variables, and the Stigma domain of the PDQ-39 scale was considered the outcome variable. Results: After multiple linear regression analysis, activities of daily living remained associated with the Stigma domain (B = 0.42 [95%CI 0.003-0.83], p = 0.048). The full model accounted for 15% of the variance in the Stigma domain (p = 0.03). Conclusions: Although causal assumptions are not appropriate for cross-sectional studies, the results suggest that ADL difficulties could contribute to greater stigma in PD patients with refractory motor symptoms who are candidates for DBS. [ABSTRACT FROM AUTHOR]

The primary etiology of Parkinson’s disease (PD) remains unclear, but likely reflects a combination of genetic and environmental factors. Exposure to some pesticides, including ziram (zinc dimethyldithiocarbamate), is a relevant risk factor for PD. Like some other environmental neurotoxicants, we hypothesized that ziram can enter the central nervous system from the nasal mucosa via the olfactory nerves. To address this issue, we evaluated the effects of 1, 2 or 4 days of intranasal (i.n., 1 mg/nostril/day) infusions of sodium dimethyldithiocarbamate (NaDMDC), a dimethyldithiocarbamate more soluble than ziram, on locomotor activity in the open field, neurological severity score and rotarod performance. We also addressed the effects of four daily i.n. NaDMDC infusions on olfactory bulb (OB) and striatal measures of cell death, reactive oxygen species (ROS), tyrosine hydroxylase, and the levels of dopamine, noradrenaline, serotonin, and their metabolites. A single i.n. administration of NaDMDC did not significantly alter the behavioral measures. Two consecutive days of i.n. NaDMDC administrations led to a transient neurological deficit that spontaneously resolved within a week. However, the i.n. infusions of NaDMDC for 4 consecutive days induced motor and neurological deficits for up to 7 days after the last NaDMDC administration and increased striatal TH immunocontent and dopamine degradation within a day of the last infusion. Pharmacological treatment with the anti-parkinsonian drugs l -DOPA and apomorphine improved the NaDMDC-induced locomotor deficits. NaDMDC increased serotonin levels and noradrenaline metabolism in the OB 24 h after the last NaDMDC infusion, ROS levels in the OB 2 h after the last infusion, and striatum 2 and 24 h after the last infusion. These results demonstrate, for the first time, that i.n. NaDMDC administration induces neurobehavioral and neurochemical impairments in mice. This accords with evidence that dimethyldithio-carbamate exposure increases the risk of PD and highlights the possibility that olfactory system could be a major route for NaDMDC entry to central nervous system. [ABSTRACT FROM AUTHOR]

Abstract: We have recently demonstrated that rodents treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) suffered impairments in olfactory, cognitive, emotional and motor functions associated with time-dependent disruption of dopaminergic neurotransmission in different brain structures conceivably analogous to those observed during different stages of Parkinson''s disease (PD). Agmatine, an endogenous arginine metabolite, has been proposed as a novel neuromodulator that plays protective roles in several models of neuronal cellular damage. In the present study we demonstrated that repeated treatment with agmatine (30mg/kg, i.p.) during 5 consecutive days increased the survival rate (from 40% to 80%) of 15-month-old C57BL/6 female mice infused with a single intranasal (i.n.) administration of MPTP (1mg/nostril), improving the general neurological status of the surviving animals. Moreover, pretreatment with agmatine was found to attenuate short-term social memory and locomotor activity impairments observed at different periods after i.n. MPTP administration. These behavioral benefits of exogenous agmatine administration were accompanied by a protection against the MPTP-induced decrease of hippocampal glutamate uptake and loss of dopaminergic neurons in the substantia nigra pars compacta of aging mice, without altering brain monoamine oxidase B (MAO-B) activity. These results provide new insights in experimental models of PD, indicating that agmatine represents a potential therapeutic tool for the management of cognitive and motor symptoms of PD, together with its neuroprotective effects. [Copyright &y& Elsevier]