Respiratory Disorders in Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) non motor symptoms may present early in the disease course and worsen with advancing disease. Respiratory changes can affect individuals to remain physically active, contributing to a reduction of functionality and quality of life. OBJECTIVE: The aim of this systematic review is to synthesize evidence of respiratory disorders in patients with PD. METHODS: An electronic search was performed up to November 2020 on PubMed-MEDLINE, Embase, Web of Science, Lilacs, Cinahl, and Cochrane using the following keyword combination: [("Parkinson disease") AND ("respiratory function tests" OR "evaluation") AND ("respiratory system" OR "respiration disorders" OR "respiratory muscles")]. RESULTS: The electronic search resulted in 601 references in English or Portuguese. The selection process and data extraction were made by two independent reviewers. We selected 19 studies including cross-sectional studies that investigated the respiratory disorders in patients with PD through pulmonary function, respiratory muscle strength, or physical capacity evaluation. We excluded studies that considered patients with other diseases. Eighteen studies evaluated the pulmonary function in patients with PD, eleven studies verified the influence of PD on respiratory muscle strength, and three studies assessed the physical capacity through functional tests. CONCLUSION: The evidence showed that PD patients have higher chances to present a pulmonary dysfunction, either obstructive or restrictive, when compared to healthy subjects. In addition, these patients present lower respiratory muscle strength and a consequent decrease in physical capacity in endurance exercises. The respiratory impairment in PD seems to be directly related to the progression of the disease.

The Effects of Intravermis Cerebellar Microinjections of Dopaminergic Agents in Motor Learning and Aversive Memory Acquisition in Mice.

The cerebellum receives dopaminergic innervation and expresses the five types of described dopaminergic receptors. The cerebellar function involves both motor movement and cognition, but the role of cerebellar dopaminergic system on these processes remain unclear. The present study explores the behavioral responses to intracerebellar microinjection of dopaminergic agents in motor and emotional memory. For this, naïve Swiss mice had their cerebellar vermis implanted with a guide canula, received a intravermis microinjection of Dopamine, D1-like antagonist SCH-23390 or D2-like antagonist Eticlopride, and underwent a behavioral analysis of motor learning (by a Rotarod and balance beam learning protocol) or aversive memory acquisition (by the inhibitory avoidance task). The mixed-effects analysis was used to evaluate groups performance, followed by Tukey's post hoc when appropriated. In this study, Dopamine, SCH-23390 and Eticlopride at the doses used did not affected motor control and motor learning. In addition, the administration of Dopamine and SCH-233390 had no effects on emotional memory acquisition, but the animals that received the highest dose of Eticlopride had an improvement in aversive memory acquisition, shown by a suppression of its innate preference for the dark compartment of the inhibitory avoidance apparatus following an exposure to a foot shock. We propose that cerebellar dopaminergic D2 receptors seem to participate on the modulation of aversive memory processes, without influencing motor performance at the doses used in this study.

Intracerebellar microinjection of histaminergic compounds on locomotor and exploratory behaviors in mice.

The neural histaminergic system innervates the cerebellum, with a high density of fibers in the vermis and flocculus. The cerebellum participates in motor functions, but the role of the histaminergic system in this function is unclear. In the present study, we investigated the effects of intracerebellar histamine injections and H1, H2 and H3 receptor antagonist injections (chlorpheniramine, ranitidine, and thioperamide, respectively) and H4 receptor agonist (VUF-8430) on locomotor and exploratory behaviors in mice. The cerebellar vermis of male mice was implanted with guide cannula. After three days of recovery,the animals received microinjections of saline or histamine (experiment1), saline or chlorpheniramine (experiment 2), saline or ranitidine(experiment 3), saline or thioperamide (experiment 4), and saline or VUF-8430 (experiment 5) in different concentrations. Five minutes postinjection,the open field test was performed. The data were analyzed using one-way ANOVA and Duncan's post hoc test. The microinjections of histamine, ranitidine or thioperamide did not lead any behavioral effects at the used doses. In contrast, animals that received chlorpheniramine at the highest dose (0.16 nmol) and VUF-8430 at the highest dose (1.48 nmol)were more active in the open field apparatus, with an increase in the number of crossed quadrants, number of rearings and time spent in the central area of the arena, suggesting that chlorpheniramine and VUF-8430 modulates locomotor and exploratory behaviors in mice.