95 research outputs found
Diet impact on Mitochondrial Bioenergetics and Dynamics
Diet induced obesity is associated with impaired mitochondrial function and dynamic behavior. Mitochondria are highly dynamic organelles and the balance in fusion/fission is strictly associated with their bioenergetics. Fusion processes are associated with the optimization of mitochondrial function, whereas fission processes are associated with the removal of damaged mitochondria. In diet-induced obesity, impaired mitochondrial function and increased fission processes were found in liver and skeletal muscle. Diverse dietary fat sources differently affect mitochondrial dynamics and bioenergetics. In contrast to saturated fatty acids, omega 3 polyunsaturated fatty acids induce fusion processes and improve mitochondrial function. Moreover, the pro-longevity effect of caloric restriction has been correlated with changes in mitochondrial dynamics leading to decreased cell oxidative injury. Noteworthy, emerging findings revealed an important role for mitochondrial dynamics within neuronal populations involved in central regulation of body energy balance. In conclusion, mitochondrial dynamic processes with their strict interconnection with mitochondrial bioenergetics are involved in energy balance and diet impact on metabolic tissues
Clinical, anatomical and pathological features in the three variants of primary progressive aphasia : a review
Primary progressive aphasias (PPA) are neurodegenerative diseases clinically
characterized by an early and relatively isolated language impairment. Three main
clinical variants, namely the nonfluent/agrammatic variant (nfvPPA), the semantic
variant (svPPA), and the logopenic variant (lvPPA) have been described, each with
specific linguistic/cognitive deficits, corresponding anatomical and most probable
pathological features. Since the discovery and the development of diagnostic criteria for
the PPA variants by the experts in the field, significant progress has been made in the
understanding of these diseases. This review aims to provide an overview of the literature
on each of the PPA variant in terms of their clinical, anatomical and pathological features,
with a specific focus on recent findings. In terms of clinical advancements, recent
studies have allowed a better characterization and differentiation of PPA patients based
on both their linguistic and non-linguistic profiles. In terms of neuroimaging, techniques
such as diffusion imaging and resting-state fMRI have allowed a deeper understanding
of the impact of PPA on structural and functional connectivity alterations beyond the
well-defined pattern of regional gray matter atrophy. Finally, in terms of pathology,
despite significant advances, clinico-pathological correspondence in PPA remains far
from absolute. Nonetheless, the improved characterization of PPA has the potential to
have a positive impact on the management of patients. Improved reliability of diagnoses
and the development of reliable in vivo biomarkers for underlying neuropathology will
also be increasingly important in the future as trials for etiology-specific treatments
become available
Music recognition in frontotemporal lobar degeneration and Alzheimer disease
Objective—To compare music recognition in patients with frontotemporal dementia, semantic
dementia, Alzheimer disease, and controls and to evaluate the relationship between music
recognition and brain volume.
Background—Recognition of familiar music depends on several levels of processing. There are
few studies about how patients with dementia recognize familiar music.
Methods—Subjects were administered tasks that assess pitch and melody discrimination,
detection of pitch errors in familiar melodies, and naming of familiar melodies.
Results—There were no group differences on pitch and melody discrimination tasks. However,
patients with semantic dementia had considerable difficulty naming familiar melodies and also
scored the lowest when asked to identify pitch errors in the same melodies. Naming familiar
melodies, but not other music tasks, was strongly related to measures of semantic memory. Voxelbased morphometry analysis of brain MRI showed that difficulty in naming songs was associated
with the bilateral temporal lobes and inferior frontal gyrus, whereas difficulty in identifying pitch
errors in familiar melodies correlated with primarily the right temporal lobe.
Conclusions—The results support a view that the anterior temporal lobes play a role in familiar
melody recognition, and that musical functions are affected differentially across forms of
dementia
Differential Patterns of Domain-Specific Cognitive Complaints and Awareness Across the Alzheimer's Disease Spectrum
Background: Characterizing self- and informant-reported cognitive complaints, as well as awareness of cognitive decline (ACD), is useful for an early diagnosis of Alzheimer's disease (AD). However, complaints and ACD related to cognitive functions other than memory are poorly studied. Furthermore, it remains unclear which source of information is the most useful to distinguish various groups on the AD spectrum. Methods: Self- and informant-reported complaints were measured with the Everyday Cognition questionnaire (ECog-Subject and ECog-StudyPartner) in four domains (memory, language, visuospatial, and executive). ACD was measured as the subject-informant discrepancy in the four ECog scores. We compared the ECog and ACD scores across cognitive domains between four groups: 71 amyloid-positive individuals with amnestic AD, 191 amnestic mild cognitive impairment (MCI), or 118 cognitively normal (CN), and 211 amyloid-negative CN controls, selected from the ADNI database. Receiver operating characteristic curves analysis was performed to evaluate the accuracy of the ECog and ACD scores in discriminating clinical groups. Results: Self- and informant-reported complaints were generally distributed as follows: memory, language, executive, and visuospatial (from the most severe to the least severe). Both groups of CN participants presented on average more memory and language complaints than their informant. MCI participants showed good agreement with their informants. AD participants presented anosognosia in all domains, but especially for the executive domain. The four ECog-StudyPartner sub-scores allowed excellent discrimination between groups in almost all classifications and performed significantly better than the other two classifiers considered. The ACD was excellent in distinguishing the participants with AD from the two groups of CN participants. The ECog-Subject was the least accurate in discriminating groups in four of the six classifications performed. Conclusion: In research, the study of complaint and anosognosia should not be reduced solely to the memory domain. In clinical practice, non-amnestic complaints could also be linked to Alzheimer's disease. The presence of an informant also seems necessary given its accuracy as a source of information
Avoiding Over-Reliance on Multi-Domain Interventions for Dementia Prevention
Given the unknown therapeutic value of targeting Alzheimer's disease pathology and the discovery of robust risk factors for dementia, non-pharmacological risk reduction (RR) is increasingly offered as an alternative to targeting Alzheimer's disease pathology. While RR will surely be a useful tool to make public health gains, we propose solutions to three possible issues with over-reliance on multi-domain interventions to achieve RR: limited individual impact, an exclusive focus on later life, and overlooking social determinants of dementia. We argue in favor of a broader debate within the research community and greater society about how different therapeutic avenues should be explored.Fil: Daly, Timothy. Sorbonne University; FranciaFil: Mastroleo, Ignacio Damian. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad de Buenos Aires; Argentina. Facultad Latinoamericana de Ciencias Sociales. Sede AcadĂ©mica Argentina Buenos Aires. Programa de BioĂ©tica; ArgentinaFil: Migliaccio, Raffaella. Sorbonne University; Franci
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