KIBRA polymorphism is associated with individual differences in hippocampal subregions: evidence from anatomical segmentation using high-resolution MRI.
The KIBRA gene has been associated with episodic memory in several recent reports; carriers of the T-allele show enhanced episodic memory performance relative to noncarriers. Gene expression studies in human and rodent species show high levels of KIBRA in the hippocampus, particularly in the subfields. The goal of the present study was to determine whether the KIBRA C→T polymorphism is also associated with volume differences in the human hippocampus and whether specific subfields are differentially affected by KIBRA genotype. High-resolution magnetic resonance imaging (T2-weighted, voxel size=0.4×0.4 mm, in-plane) was used to manually segment hippocampal cornu ammonis (CA) subfields, dentate gyrus (DG), and the subiculum as well as adjacent medial temporal lobe cortices in healthy carriers and noncarriers of the KIBRA T-allele (rs17070145). Overall, we found that T-carriers had a larger hippocampal volume relative to noncarriers. The structural differences observed were specific to the CA fields and DG regions of the hippocampus, suggesting a potential neural mechanism for the effects of KIBRA on episodic memory performance reported previously.
Rotman Research Institute at Baycrest Hospital, Toronto, Ontario M6A 2E1 Canada.
Daniela J
DJ
Palombo
Robert S C
RS
Amaral
Rosanna K
RK
Olsen
Daniel J
DJ
Müller
Rebecca M
RM
Todd
Adam K
AK
Anderson
Brian
B
Levine
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D005838:Genotype; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007206:Individuality; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D010750:Phosphoproteins / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D015203:Reproducibility of Results; D055815:Young Adult
D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; C513637:WWC1 protein, human