Altered neural network supporting declarative long-term memory in mild cognitive impairment.
Autobiographical episodic memory represents a subsystem of declarative long-term memory and largely depends on combining information from multiple sources. The purpose of this study was to assess neural correlates of declarative long-term memory in patients with amnestic mild cognitive impairment (MCI) and controls using fMRI and a task requiring autobiographical and semantic memory retrieval. Comparison of the network supporting episodic autobiographical and semantic memory irrespective of remoteness (recent and remote) revealed significant activations in right parietal cortex and precuneus bilaterally in the patients. Autobiographical episodic versus semantic memory retrieval in the controls led to significant bilateral activations of the parietal-temporal junction, left temporal pole, anterior cingulate, retrosplenial cortex and cerebellum. In contrast, MCI patients activated left supplementary motor area, left premotor and superior temporal cortex. In MCI patients compared to controls a dysfunction of the retrosplenial cortex during memory retrieval was revealed by a lack of differential activation in relation to recency of memories and memory type. Our data suggest that MCI leads to a loss of specificity in the neural network supporting declarative long-term memory.
Poettrich
Katrin
K
Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden, Germany. Katrin.Poettrich@uniklinikum-dresden.de
Weiss
Peter H
PH
Werner
Annett
A
Lux
Silke
S
Donix
Markus
M
Gerber
Johannes
J
von Kummer
Rüdiger
R
Fink
Gereon R
GR
Holthoff
Vjera A
VA
D000647:Amnesia / Q000503:physiopathology*; D001325:Autobiographies as Topic; D001921:Brain / Q000503:physiopathology*; D003072:Cognition Disorders / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D012660:Semantics