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Dynamic functional reorganizations and relationship with working memory performance in healthy aging.

Sala-Llonch R, Arenaza-Urquijo EM, Valls-Pedret C, Vidal-Piñeiro D, Bargalló N, Junqué C, Bartrés-Faz D - Front Hum Neurosci (2012)

Bottom Line: Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks.We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks.We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging.

View Article: PubMed Central - PubMed

Affiliation: Departament de Psiquiatria i Psicobiologia Clinica, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain.

ABSTRACT
In recent years, several theories have been proposed in attempts to identify the neural mechanisms underlying successful cognitive aging. Old subjects show increased neural activity during the performance of tasks, mainly in prefrontal areas, which is interpreted as a compensatory mechanism linked to functional brain efficiency. Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks. We used functional MRI during resting-state and a verbal n-back task with different levels of memory load in a cohort of young and old healthy adults to identify patterns of networks associated with working memory and brain default mode. We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks. Moreover, elders who were able to activate additional areas and to recruit a more bilateral frontal pattern within the task-related network achieved successful performance on the task. We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging. This observation allows the integration of several theories that have been proposed to date regarding the aging brain.

No MeSH data available.


Related in: MedlinePlus

Results of the ROI-based analysis of brain activity during the performance of the n-back task. Within each defined ROI, percent signal change are plotted for each group and condition. *Indicates that differences have a significance value of p < 0.05.
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Figure 5: Results of the ROI-based analysis of brain activity during the performance of the n-back task. Within each defined ROI, percent signal change are plotted for each group and condition. *Indicates that differences have a significance value of p < 0.05.

Mentions: We focused the analysis of task-fMRI data on a set of spherical ROIs that were selected from the networks identified in the resting-fMRI analysis (Figure 5). Three ROIs were created from the right-FPN: one in the right inferior frontal gyrus: right-IFG ROI (MNI coordinates: x = 42, y = 54, z = −4), one in the right middle frontal gyrus: right-MFG ROI (MNI coordinates: x = 46, y = 34, z = 32) and one in the right superior parietal gyrus: right-PAR ROI (MNI coordinates: x = 42, y = −58, z = 52). Three were created from the left-FPN: one in the left inferior frontal gyrus: left-IFG ROI (MNI coordinates: x = −46, y = 50, z = 0), one in the left middle frontal gyrus: left-MFG ROI (MNI coordinates: x = −46, y = 34, z = 20), and one in the left superior parietal gyrus: left-PAR ROI (x = −46, y = −50, z = 31). We also selected a region in the anterior cingulate cortex that was common for the right-FPN and the left-FPN: ACC ROI (MNI coordinates: x = −2, y = 26, z = 44). As regards the DMN, we defined four ROIs, one in the precuneus and posterior cingulate cortex: PCC ROI (MNI coordinates: x = 2, y = −66, z = 40), two in the left and right lateral occipital cortices: LLO ROI (MNI coordinates: x = −38, y = −82, z = 32), and RLO ROI (MNI coordinates: x = 42, y = −74, z = 36) and one in the middle frontal cortex: MFC ROI (MNI coordinates: x = 2, y = 58, z = −8).


Dynamic functional reorganizations and relationship with working memory performance in healthy aging.

Sala-Llonch R, Arenaza-Urquijo EM, Valls-Pedret C, Vidal-Piñeiro D, Bargalló N, Junqué C, Bartrés-Faz D - Front Hum Neurosci (2012)

Results of the ROI-based analysis of brain activity during the performance of the n-back task. Within each defined ROI, percent signal change are plotted for each group and condition. *Indicates that differences have a significance value of p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369258&req=5

Figure 5: Results of the ROI-based analysis of brain activity during the performance of the n-back task. Within each defined ROI, percent signal change are plotted for each group and condition. *Indicates that differences have a significance value of p < 0.05.
Mentions: We focused the analysis of task-fMRI data on a set of spherical ROIs that were selected from the networks identified in the resting-fMRI analysis (Figure 5). Three ROIs were created from the right-FPN: one in the right inferior frontal gyrus: right-IFG ROI (MNI coordinates: x = 42, y = 54, z = −4), one in the right middle frontal gyrus: right-MFG ROI (MNI coordinates: x = 46, y = 34, z = 32) and one in the right superior parietal gyrus: right-PAR ROI (MNI coordinates: x = 42, y = −58, z = 52). Three were created from the left-FPN: one in the left inferior frontal gyrus: left-IFG ROI (MNI coordinates: x = −46, y = 50, z = 0), one in the left middle frontal gyrus: left-MFG ROI (MNI coordinates: x = −46, y = 34, z = 20), and one in the left superior parietal gyrus: left-PAR ROI (x = −46, y = −50, z = 31). We also selected a region in the anterior cingulate cortex that was common for the right-FPN and the left-FPN: ACC ROI (MNI coordinates: x = −2, y = 26, z = 44). As regards the DMN, we defined four ROIs, one in the precuneus and posterior cingulate cortex: PCC ROI (MNI coordinates: x = 2, y = −66, z = 40), two in the left and right lateral occipital cortices: LLO ROI (MNI coordinates: x = −38, y = −82, z = 32), and RLO ROI (MNI coordinates: x = 42, y = −74, z = 36) and one in the middle frontal cortex: MFC ROI (MNI coordinates: x = 2, y = 58, z = −8).

Bottom Line: Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks.We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks.We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging.

View Article: PubMed Central - PubMed

Affiliation: Departament de Psiquiatria i Psicobiologia Clinica, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain.

ABSTRACT
In recent years, several theories have been proposed in attempts to identify the neural mechanisms underlying successful cognitive aging. Old subjects show increased neural activity during the performance of tasks, mainly in prefrontal areas, which is interpreted as a compensatory mechanism linked to functional brain efficiency. Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks. We used functional MRI during resting-state and a verbal n-back task with different levels of memory load in a cohort of young and old healthy adults to identify patterns of networks associated with working memory and brain default mode. We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks. Moreover, elders who were able to activate additional areas and to recruit a more bilateral frontal pattern within the task-related network achieved successful performance on the task. We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging. This observation allows the integration of several theories that have been proposed to date regarding the aging brain.

No MeSH data available.


Related in: MedlinePlus