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Titolo:
Altered brain functional connectivity and impaired short-term memory in Alzheimer's disease
Autore:
Grady, CL; Furey, ML; Pietrini, P; Horwitz, B; Rapoport, SI;
Indirizzi:
Univ Toronto, Baycrest Ctr Geriat Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada Univ Toronto Toronto ON Canada M6A 2E1 Inst, Toronto, ON M6A 2E1, Canada NIMH, Lab Brain & Cognit, Bethesda, MD 20892 USA NIMH Bethesda MD USA 20892 MH, Lab Brain & Cognit, Bethesda, MD 20892 USA Natl Inst Deafness & Other Commun Disorders, Voice Speech & Language Branch, Language Sect, Bethesda, MD USA Natl Inst Deafness & Other Commun Disorders Bethesda MD USA esda, MD USA NIA, Sect Brain Physiol & Metab, Bethesda, MD USA NIA Bethesda MD USANIA, Sect Brain Physiol & Metab, Bethesda, MD USA Univ Pisa, Dept Human & Environm Sci, Pisa, Italy Univ Pisa Pisa ItalyUniv Pisa, Dept Human & Environm Sci, Pisa, Italy
Titolo Testata:
BRAIN
, volume: 124, anno: 2001,
parte:, 4
pagine: 739 - 756
SICI:
0006-8950(200104)124:<739:ABFCAI>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
POSITRON EMISSION TOMOGRAPHY; CEREBRAL BLOOD-FLOW; EMOTIONAL FACIAL EXPRESSIONS; CORTICAL GLUCOSE-UTILIZATION; FACE PROCESSING IMPAIRMENTS; HUMAN EXTRASTRIATE CORTEX; PARTIAL LEAST-SQUARES; HUMAN WORKING-MEMORY; AGE-RELATED-CHANGES; RECOGNITION MEMORY;
Keywords:
neuroimaging; dementia; face recognition; PET; memory;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
74
Recensione:
Indirizzi per estratti:
Indirizzo: Grady, CL Univ Toronto, Baycrest Ctr Geriat Care, Rotman Res Inst, 3560 Bathurst St,Toronto, ON M6A 2E1, Canada Univ Toronto 3560 Bathurst St TorontoON Canada M6A 2E1 , Canada
Citazione:
C.L. Grady et al., "Altered brain functional connectivity and impaired short-term memory in Alzheimer's disease", BRAIN, 124, 2001, pp. 739-756

Abstract

To examine functional interactions between prefrontal and medial temporal brain areas during face memory, blood flow was measured in patients with Alzheimer's disease and healthy controls using PET. We hypothesized that controls would show correlated activity between frontal and posterior brain areas, including the medial temporal cortex, whereas patients would not, although frontal activity per se might be spared or even increased compared withcontrols, We used a delayed match to sample paradigm with delays from 1 to16 s, There was no change in recognition accuracy with increasing delay incontrols, whereas patients showed impaired recognition over all delays that worsened as delay increased. Controls showed increased activity in the bilateral prefrontal and parietal cortex with increasing delay, whereas the patients had increased activity in the right prefrontal, anterior cingulate and left amygdala, Increased activity in the right prefrontal cortex was associated with better memory performance in both groups and activity in the left amygdala was correlated with better performance in the patients, Basedon these task and behavioural effects, we examined functional connectivityof the right prefrontal cortex and left amygdala in both groups by determining those areas whose activity was correlated with activity in these regions, In controls, activity in the right prefrontal cortex was positively correlated with blood flow in the left prefrontal cortex, bilateral extrastriate and parietal areas and the right hippocampus. In patients, activity in the right prefrontal cortex was correlated mainly with other prefrontal regions, Areas where activity was correlated with the left amygdala in patientsincluded the bilateral posterior parahippocampal gyri, a number of left prefrontal regions, anterior and posterior cingulate, thalamus, and insula, Controls had a relatively restricted set of regions where activity correlated with the left amygdala, mainly temporal and occipital areas, These results support the idea of a functional disconnection between the prefrontal cortex and the hippocampus in Alzheimer's disease and suggest that memory breakdown in early Alzheimer's disease is related to a reduction in the integrated activity within a distributed network that includes these two areas. The unexpected finding of increased involvement of the amygdala suggests thatthe patients may have processed the emotional content of the faces to a greater degree than did the controls, Furthermore, the positive association between amygdala activity and memory performance in the patients suggests a possible compensatory role for an emotion-related network of regions.

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Documento generato il 18/01/20 alle ore 22:07:29