Poster Session 04 Program Schedule
02/15/2024
12:00 pm - 01:15 pm
Room: Majestic Complex (Posters 61-120)
Poster Session 04: Neuroimaging | Neurostimulation/Neuromodulation | Teleneuropsychology/Technology
Final Abstract #83
Increased Glucose and CA4 Volume Interact to Promote Hippocampal Memory Function
Sarah Norman, University of Arizona, Tucson, United States
Siobhan Hoscheidt, University of Arizona, Tucson, United States
Stephanie Matijevic, University of Arizona, Tucson, United States
Lee Ryan, University of Arizona, Tucson, United States
Category: Cognitive Neuroscience
Keyword 1: hippocampus
Keyword 2: memory: normal
Keyword 3: aging (normal)
Objective:
Research suggests that glucose promotes hippocampal memory function and that the dentate gyrus (CA4) is particularly affected by glucose. Glucose regulation is gradually impaired with age and may contribute, at least in part, to normal cognitive decline. There may be factors; however, such as hippocampal volume, that mediate the effects of glucose on memory function. The present study examined the association between glucose and memory performance on a hippocampal-dependent memory task examining hippocampal subfield volume as a potential mediating factor.
Participants and Methods:
Twenty-six cognitively asymptomatic older adults (mean age 68.9 ± 6.56 years, range=59-80 years, 73% female) underwent oral glucose tolerance testing (OGTT), neuropsychological testing, and magnetic resonance imaging (MRI). Blood glucose levels were obtained at fasting, one hour- and two hours- post glucose ingestion. Directly after glucose consumption, participants were administered the Rey Auditory Verbal Learning Test (AVLT). Structural MRI scans were used to calculate hippocampal volumes, including subfields, using FreeSurfer (version 6).
Results:
Higher blood glucose levels relative to baseline (1hr post OGTT - fasting) were significantly associated with better memory performance on the delayed AVLT but only in individuals with larger volumes of the CA4 body. This relationship was also observed in the granular cell molecular layer of the dentate gyrus body. Findings were significant in the left, but not right, hippocampus. This relationship was not significant in other hippocampal subfields on either side.
Conclusions:
Results further substantiate the critical role of glucose in hippocampal-dependent processes and suggest that increased glucose and volume of the left hippocampus, specifically the dentate gyrus and granular cell molecular layer, interact to promote hippocampal memory function. Findings provide evidence that glucose alone may not be sufficient to promote hippocampal-dependent memory, particularly in aging. The concomitant effect of glucose and the structural integrity of the CA4 region may be an important factor in sustaining normal cognitive function.
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