Simvastatin Prevents Dopaminergic Neurodegeneration in Experimental Parkinsonian Models: The Association with Anti-Inflammatory Responses

Background: In addition to their original applications to lowering cholesterol, statins display multiple neuroprotective effects. N-methyl-D-aspartate (NMDA) receptors interact closely with the dopaminergic system and are strongly implicated in therapeutic paradigms of Parkinson’s disease (PD). This study aims to investigate how simvastatin impacts on experimental parkinsonian models via regulating NMDA receptors. Methodology/Principal Findings: Regional changes in NMDA receptors in the rat brain and anxiolytic-like activity were examined after unilateral medial forebrain bundle lesion by 6-hydroxydopamine via a 3-week administration of simvastatin. NMDA receptor alterations in the post-mortem rat brain were detected by [3H]MK-801(Dizocilpine) binding autoradiography. 6-hydroxydopamine treated PC12 was applied to investigate the neuroprotection of simvastatin, the association with NMDA receptors, and the anti-inflammation. 6-hydroxydopamine induced anxiety and the downregulation of NMDA receptors in the hippocampus, CA1(Cornu Ammonis 1 Area), amygdala and caudate putamen was observed in 6- OHDA(6-hydroxydopamine) lesioned rats whereas simvastatin significantly ameliorated the anxiety-like activity and restored the expression of NMDA receptors in examined brain regions. Significant positive correlations were identified between anxiolytic-like activity and the restoration of expression of NMDA receptors in the hippocampus, amygdala and CA1 following simvastatin administration. Simvastatin exerted neuroprotection in 6-hydroxydopamine-lesioned rat brain and 6- hydroxydopamine treated PC12, partially by regulating NMDA receptors, MMP9 (matrix metalloproteinase-9), and TNF-a (tumour necrosis factor-alpha). Conclusions/Significance: Our results provide strong evidence that NMDA receptor modulation after simvastatin treatment could partially explain its anxiolytic-like activity and anti-inflammatory mechanisms in experimental parkinsonian models. These findings contribute to a better understanding of the critical roles of simvastatin in treating PD via NMDA receptors

Fearing Parkinson’s Disease: Relationships Between Cognition and Emotion

There is a growing interest in elucidating the etiopathogenesis of different neurodegenerative processes, and this chapter particularly focuses on Parkinson’s disease (PD). PD is the second most common neurodegenerative disease affecting 2% of the population over 65 years old, a consequence of the vulnerability of dopaminergic neurons associated with age. It is characterized by well-known motor symptoms, whereas the presence of non-motor symptoms, such as cognitive dysfunctions and emotional disturbances, are still underestimated. The degeneration of the nigrostriatal dopaminergic pathway results in functional-morphological changes in synaptic plasticity and architecture in fundamental areas for the processing of emotional memory (basolateral amygdala and hippocampus). Thereby, the cognitive–emotional deficit would be a critical predictive sign of motor alterations in the pathology progression. The mechanisms involved are still unknown. Currently, no treatment has been shown to modify the evolution of the degenerative process, much less the associated non-motor symptoms. Besides, several studies are advancing in the comprehension of multiple processes involved in the establishment of this neuropathology. This chapter focuses on cognition and emotion interactions in PD and their relevance to patient and caregiver quality of life. To this end, we will address the latest studies about neurocircuitries, regulation networks and possible therapeutic approaches in different parkinsonism experimental models.Fil: Herrera, Macarena Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Champarini, Leandro Gabriel. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Otamendi, Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Hereñú, Claudia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacología; Argentin