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Altered hippocampal activation during memory encoding in type 2 diabetes
Author(s) -
Meusel LieselAnn Catharine,
Anderson Nicole,
Tchistiakova Ekaterina,
MacIntosh Brad,
Greenwood Carol
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.840.12
Subject(s) - dementia , cognitive decline , hippocampal formation , neuropsychology , episodic memory , cognition , hippocampus , type 2 diabetes , effects of sleep deprivation on cognitive performance , memory impairment , medicine , audiology , psychology , neuroscience , diabetes mellitus , endocrinology , disease
Type 2 diabetes (T2DM) increases risk for cognitive decline and dementia. While much is known about T2DM‐associated cognitive changes and brain atrophy, the impact of T2DM on brain function is underexplored. Blood oxygenation level dependent (BOLD) signal changes were compared in older adults with T2DM and hypertension (DO, n = 9) and older adults with hypertension only (HO, n = 10) during a cerebrovascular reactivity (CVR) task and a word‐list learning task. We hypothesized that memory deficits and altered BOLD signaling would be apparent in DO compared to HO but that CVR, obtained during a breath‐hold task, would be comparable. There were no group differences in performance on neuropsychological memory tests nor on the word‐list learning task. A region‐of‐interest analysis on hippocampal (HC) activation during word‐list encoding showed stronger right HC activation in the DO compared to the HO group after accounting for CVR (p < .01). Across groups, there was a significant negative correlation between right HC activation and number of words learned during encoding, controlling for performance on the first trial (r = −0.61, p < .01). Collectively these findings suggest that 1) T2DM elevates memory‐related activation of right HC independent of vascular reactivity, and 2) increases in right HC activation parallel decreased learning success and may signal efforts to compensate for cognitive decline (CIHR – MOP111244). Grant Funding Source : Canadian Institutes of Health Research