Alzheimer's disease risk variant in CLU is associated with neural inefficiency in healthy individuals

Introduction: Genome-wide association studies identify rs11136000 in the CLU gene, which codes for Apolipoprotein J/Clusterin, as a significant risk variant for Alzheimer's disease (AD). However, the mechanisms by which this variant confers susceptibility remain relatively unknown. Methods: Eighty-five healthy Caucasian participants underwent functional magnetic resonance imaging during a working memory (WM) task and were genotyped for CLU rs11136000/APOE loci. Results: Here we show that young individuals with the CLU rs11136000 risk variant (C) have higher activation levels in memory-related prefrontal and limbic areas during a WMtask. We also found subtle reductions in gray matter in the right hippocampal formation in carriers of the risk variant. Discussion: We suggest that this pattern of multimodal imaging results may reflect incipient structural differences and inefficient functional activation. This study supports accumulating evidence suggesting that genetic risk for AD affects the neural networks associated with memory in healthy individuals. (C) 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.