Physical activity and environmental enrichment regulate the generation of neural precursors in the adult mouse substantia nigra in a dopamine-dependent manner

Nicotine has been defined as a potent parasympathomimetic alkaloid that accumulates in the roots and leaves of Nightshade family of plants Aim: This study was aimed at evaluating the effects of orally ingested nicotine in the histology of hippocampus, substantia nigra and cerebellum.Materials and Methods: Twenty four adult male Wistar rats (100g – 200g) were randomly divided into 4 groups (group 1 – group 4). Group 1 served as the control group, while groups 2 - 4 were the treated groups. Nicotine was diluted in water and 1ml of the different dosage (2mg/kg/day, 4mg/kg/day and 6mg/kg/day) were administered to the treated groups respectively with the aid of orogastric cannula for 42 days. Animals were euthanized by cervical dislocation at the end of 7, 21 and 42 days so as to demonstrate the dose and time dependant effect of this agent. Brain tissues were harvested, processed and stained using Haematoxylin and eosin according to standard histological techniques. Stained tissue images were captured using digital micrometer eyepiece and cell count was determined using stereological technique.Statistical analysis: Data obtained were subjected to statistical analysis with the use of statistical package for social sciences (SPSS version 20). Significant differences were obtained using One Way Analysis of Variance with a probability of 0.05 (95% confidence limit) and Tukeys post hoc test was further used to determine the mean significant differences between specific groups.Results: Histological findings showed mild, moderate and severe hyperplasia in a dose and time dependant manner. However, observations from quantitative analysisalso revealed a dose and time dependant significant increase in neuronal cell count and cell diameter of the hippocampus, Substantia nigra and cerebellum.Conclusion: This study has demonstrated that oral exposure of Nicotine in rats display proliferative adaptive changes on the hippocampus, substantia nigra and cerebellum in a dose/time dependent manner.

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Regular Physical Activity and Risk of Venous Thromboembolism

Seminars in Thrombosis and Hemostasis ◽

10.1055/s-0038-1673636 ◽

2018 ◽

Vol 44 (08) ◽

pp. 765-779 ◽

Cited By ~ 6

Author(s):

Sigrid Brækkan ◽

John-Bjarne Hansen ◽

Line Evensen

Keyword(s):

Physical Activity ◽

Venous Thromboembolism ◽

Current Knowledge ◽

Objective Assessment ◽

Operational Definition ◽

Assessment Method ◽

Health Concern ◽

Future Research ◽

Dependent Manner

AbstractVenous thromboembolism (VTE) is a complex multifactorial disease that represents a growing public health concern. Identification of modifiable risk factors at the population level may provide a measure to reduce the burden of VTE. In this review, we summarize current knowledge of the role of physical activity on the risk of VTE and VTE-related complications. We also discuss methodological challenges related to research on physical activity, and put forward plausible mechanisms for an association between physical activity and VTE. Up to now, published studies have reported diverging results on the relationship between physical activity and VTE, and a complex picture has emerged. However, the available evidence appears to be balanced toward a small beneficial effect of physical activity on the risk of incident VTE, but not in a dose-dependent manner. Still, the lack of an operational definition and standardized assessment method for physical activity, as well as several sources of bias, impairs the interpretation of the available literature. Additional work is necessary to understand the role and how to apply physical activity in the VTE setting. Future research should utilize objective assessment strategies of physical activity and physical fitness, account for the fluctuating nature in habitual activity levels, and explore the role of physical activity in the areas of secondary prevention and VTE-related complications.

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