Neurobiology of disease
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Neurobiology of disease · Jun 2012
ReviewCardiovascular dysautonomia in Parkinson disease: from pathophysiology to pathogenesis.
Signs or symptoms of impaired autonomic regulation of circulation often attend Parkinson disease (PD). This review covers biomarkers and mechanisms of autonomic cardiovascular abnormalities in PD and related alpha-synucleinopathies. The clearest clinical laboratory correlate of dysautonomia in PD is loss of myocardial noradrenergic innervation, detected by cardiac sympathetic neuroimaging. ⋯ Alpha-synucleinopathy in autonomic neurons may occur early in the pathogenetic process. The timing of cardiac noradrenergic denervation in PD is therefore a key issue. This review updates the field of autonomic cardiovascular abnormalities in PD and related disorders, with emphasis on relationships among striatal dopamine depletion, sympathetic noradrenergic denervation, and alpha-synucleinopathy.
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Neurobiology of disease · Jun 2012
ReviewREM sleep behavior disorder: from dreams to neurodegeneration.
REM sleep behavior disorder is a unique parasomnia characterized by dream enactment behavior during REM sleep. Unless triggered by pharmacologic agents such as antidepressants, it is generally related to damage of pontomedullary brainstem structures. Idiopathic REM sleep behavior disorder (RBD) is a well-established risk factor for neurodegenerative disease. ⋯ The interval between RBD onset and disease onset averages 10-15 years, suggesting a promisingly large window for intervention into preclinical disease stages. The ability of RBD to predict disease has major implications for design and development of neuroprotective therapy, and testing of other predictive markers of synuclein-mediated neurodegeneration. Recent studies in idiopathic RBD patients have demonstrated that olfaction, color vision, severity of REM atonia loss, transcranial ultrasound of the substantia nigra, and dopaminergic neuroimaging can predict development of neurodegenerative disease.
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Neurobiology of disease · Jun 2012
Combined inhibition of cell death induced by apoptosis inducing factor and caspases provides additive neuroprotection in experimental traumatic brain injury.
Neuronal programmed cell death (PCD) contributes to delayed tissue damage after traumatic brain injury (TBI). Both caspase-dependent and caspase-independent mechanisms have been implicated, with the latter including apoptosis inducing factor (AIF). The peptidyl-proplyl isomerase Cyclophilin A (CypA) transports AIF from the cytosol to the nucleus, a key step for AIF-dependent cell death. ⋯ Importantly, BAF-treated CypA(-/-) mice, showed greater effects than either intervention alone on multiple outcomes including: reduction in TUNEL-positive cells, decrease in neuroinflammation, improved motor and cognitive recovery, and attenuation of lesion volume and neuronal loss in the hippocampus. Using two in vitro neuronal cell death models known to induce AIF-mediated PCD, we also showed that neurons from CypA(-/-) animals were protected and that effects were unrelated to caspase activation. These data indicate that AIF-mediated and caspase-dependent pathways contribute independently and in parallel to secondary injury after TBI, and suggest that combined therapeutic strategies directed at multiple PCD pathways may provide superior neuroprotection than those directed at single mechanisms.