Vidal-Pineiro D.,University of Barcelona |
Martin-Trias P.,University of Barcelona |
Arenaza-Urquijo E.M.,University of Barcelona |
Sala-Llonch R.,University of Barcelona |
And 10 more authors.
Brain Stimulation | Year: 2014
Background Transcranial magnetic stimulation (TMS) can affect episodic memory, one of the main cognitive hallmarks of aging, but the mechanisms of action remain unclear. Objectives To evaluate the behavioral and functional impact of excitatory TMS in a group of healthy elders. Methods We applied a paradigm of repetitive TMS - intermittent theta-burst stimulation - over left inferior frontal gyrus in healthy elders (n = 24) and evaluated its impact on the performance of an episodic memory task with two levels of processing and the associated brain activity as captured by a pre and post fMRI scans. Results In the post-TMS fMRI we found TMS-related activity increases in left prefrontal and cerebellum-occipital areas specifically during deep encoding but not during shallow encoding or at rest. Furthermore, we found a task-dependent change in connectivity during the encoding task between cerebellum-occipital areas and the TMS-targeted left inferior frontal region. This connectivity change correlated with the TMS effects over brain networks. Conclusions The results suggest that the aged brain responds to brain stimulation in a state-dependent manner as engaged by different tasks components and that TMS effect is related to inter-individual connectivity changes measures. These findings reveal fundamental insights into brain network dynamics in aging and the capacity to probe them with combined behavioral and stimulation approaches. © 2014 Elsevier Inc.
Madrigal I.,CIBER ISCIII |
Xuncla M.,Fundacio Clinic per A la Recerca Biome Dica |
Tejada M.I.,Cruces Hospital |
Martinez F.,Hospital Universitario La Paz |
And 5 more authors.
European Journal of Human Genetics | Year: 2011
During the last few years, several studies have reported an excess of intermediate FMR1 alleles in patients with cognitive and/or behavioural phenotypes. Here, we report the frequency of intermediate alleles (IAs) in three pathologies, intellectual disabilities (IDs), attention-deficit/hyperactivity disorder and autism, from different Spanish regions. We found 142 IAs among 9015 patients with ID (1.6%), 4 among the 415 ADHD patients (0.96%) and 4 among the 300 autistic patients (1.3%), similar to the frequency reported in our control population. No evidence was found of an excess of IA at the FRAXA locus in any of the study populations, although geographical variability was detected. Moreover, the analysis of 100 transmissions of IAs showed that 95% of these alleles were stable. Only 3% expanded within the same range and 2% expanded to a full mutation in two generations. No evidence of an association between IAs and behavioural or cognitive phenotypes was found, suggesting that IAs are not clearly implicated in these pathologies. © 2011 Macmillan Publishers Limited All rights reserved.