GABA levels in ventral visual cortex decline with age and are associated with neural distinctiveness

NEUROBIOLOGY OF AGING

卷:102

Article

Chamberlain, Jordan D.¹  Gagnon, Holly²  Lalwani, Poortata²  Cassady, Kaitlin E.²  Simmonite, Molly²  Seidler, Rachael D.³  Taylor, Stephan F.⁴  Weissman, Daniel H.²  Park, Denise C.⁵  Polk, Thad A.⁶ 

[1] Penn State Univ, Dept Psychol, University Pk, PA 16802 USA

[2] Univ Utah, Dept Psychol, Salt Lake City, UT 84112 USA

[3] Univ Florida, Dept Appl Physiol & Kinesiol, Gainesville, FL USA

[4] Univ Michigan, Dept Psychiat, Ann Arbor, MI 48109 USA

[5] Univ Texas Dallas, Ctr Vital Longev, Dallas, TX USA

[6] Univ Michigan, Dept Psychol, 580 Union Dr, Ann Arbor, MI 48109 USA

关键词: Aging;    Dedifferentiation;    fMRI;    GABA;    Multivariate pattern analysis;    MR spectroscopy;   

DOI  :  10.1016/j.neurobiolaging.2021.02.013

来源: Elsevier

【 摘 要 】

Age-related neural dedifferentiation-a decline in the distinctiveness of neural representations in the aging brain-has been associated with age-related declines in cognitive abilities. But why does neural distinctiveness decline with age? Based on prior work in nonhuman primates and more recent work in humans, we hypothesized that the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) declines with age and is associated with neural dedifferentiation in older adults. To test this hypothesis, we used magnetic resonance spectroscopy (MRS) to measure GABA and functional MRI (fMRI) to measure neural distinctiveness in the ventral visual cortex in a set of older and younger participants. Relative to younger adults, older adults exhibited lower GABA levels and less distinct activation patterns for faces and houses in the ventral visual cortex. Furthermore, individual differences in GABA within older adults positively predicted individual differences in neural distinctiveness. These results provide novel support for the view that age-related reductions of GABA contribute to age-related reductions in neural distinctiveness (i.e., neural dedifferentiation) in the human ventral visual cortex. (c) 2021 Elsevier Inc. All rights reserved.

【 授权许可】

Free