Yaojing Chen1, Zhen Liu1, Ailin Wang1, Junying Zhang1, Sisi Zhang1, Di Qi1, Kewei Chen2, Zhanjun Zhang3. 1. State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, PR China; BABRI Centre, Beijing Normal University, Beijing 100875, PR China. 2. Banner Alzheimer's Institute, Phoenix, AZ 85006, USA; BABRI Centre, Beijing Normal University, Beijing 100875, PR China. 3. State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, PR China; BABRI Centre, Beijing Normal University, Beijing 100875, PR China. Electronic address: zhang_rzs@bnu.edu.cn.
Abstract
AIMS: Episodic memory depends on the maintenance of an intact default mode network (DMN), and is one of the earliest cognitive domains to become impaired in type 2 diabetes mellitus (T2DM). Therefore, exploring the alterations in task-related DMN deactivation and functional connectivity that affect episodic memory in T2DM will help to enhance our understanding of the allocation patterns underlying memory function in T2DM. METHODS: The current study assessed changes in DMN activation and architecture during the encoding of a functional magnetic resonance imaging task in 39 patients with T2DM and 41 healthy controls which were recruited from local communities in Beijing, China. RESULTS: We found that patients with T2DM and intact episodic memory performance exhibited reduced deactivation in the right precuneus and the middle temporal gyrus during the episodic memory task. Furthermore, an anterior-posterior disconnection phenotype and altered topological configuration of the DMN were observed in patients with T2DM using graph-theoretical approaches. Correlation analysis showed that altered deactivation during the episodic memory task was closely related to connectivity dysfunction and topological properties in the DMN. CONCLUSIONS: Our findings demonstrate that the maintenance of memory in patients with T2DM involves reduced deactivation and impaired anterior-posterior connections in the DMN during encoding.
AIMS: Episodic memory depends on the maintenance of an intact default mode network (DMN), and is one of the earliest cognitive domains to become impaired in type 2 diabetes mellitus (T2DM). Therefore, exploring the alterations in task-related DMN deactivation and functional connectivity that affect episodic memory in T2DM will help to enhance our understanding of the allocation patterns underlying memory function in T2DM. METHODS: The current study assessed changes in DMN activation and architecture during the encoding of a functional magnetic resonance imaging task in 39 patients with T2DM and 41 healthy controls which were recruited from local communities in Beijing, China. RESULTS: We found that patients with T2DM and intact episodic memory performance exhibited reduced deactivation in the right precuneus and the middle temporal gyrus during the episodic memory task. Furthermore, an anterior-posterior disconnection phenotype and altered topological configuration of the DMN were observed in patients with T2DM using graph-theoretical approaches. Correlation analysis showed that altered deactivation during the episodic memory task was closely related to connectivity dysfunction and topological properties in the DMN. CONCLUSIONS: Our findings demonstrate that the maintenance of memory in patients with T2DM involves reduced deactivation and impaired anterior-posterior connections in the DMN during encoding.
Authors: Frank C G van Bussel; Walter H Backes; Paul A M Hofman; Robert J van Oostenbrugge; Martin P J van Boxtel; Frans R J Verhey; Harry W M Steinbusch; Miranda T Schram; Coen D A Stehouwer; Joachim E Wildberger; Jacobus F A Jansen Journal: Front Neurosci Date: 2017-04-05 Impact factor: 4.677