COMT genotype and its role on hippocampal-prefrontal regions in declarative memory.
BACKGROUND
Memory dysfunction is a prominent feature in schizophrenia. Impairments of declarative memory have been consistently linked to alterations especially within hippocampal-prefrontal regions. Due to the high heritability of schizophrenia, susceptibility genes and their modulatory impact on the neural correlates on memory are of major relevance. In the present study the influence of the COMT val(158)met status on the neural correlates of declarative memory was investigated in healthy subjects.


METHODS
From an initial behavioural sample of 522 healthy individuals (Sheldrick et al., 2008), 84 subjects underwent fMRI scanning while performing a memory encoding and a retrieval task. The COMT val(158)met status was determined for the whole sample and correlated with cortical activation within the group of n=84 individuals.


RESULTS
There were no effects of COMT status on behavioural performance. For declarative memory processing the number of met alleles predicted circumscribed bilateral insula and anterior hippocampus activations during memory encoding as well as less deactivations within the bilateral posterior parahippocampal gyri during memory retrieval.


CONCLUSIONS
Although declarative memory performance was unaffected, the neural correlates within hippocampal-prefrontal regions demonstrate a link between COMT val(158)met carrier status and brain areas associated with declarative memory processing. The study contributes to a better understanding of the role that susceptibility genes might play in the aetiology of schizophrenia.
Krach
Sören
S
Department of Psychiatry and Psychotherapy, Section of Brain Imaging, Philipps-University Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany. krachs@med.uni-marburg.de
Jansen
Andreas
A
Krug
Axel
A
Markov
Valentin
V
Thimm
Markus
M
Sheldrick
Abigail J
AJ
Eggermann
Thomas
T
Zerres
Klaus
K
Stöcker
Tony
T
Shah
N Jon
NJ
Kircher
Tilo
T
D001931:Brain Mapping; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D020641:Polymorphism, Single Nucleotide; D017397:Prefrontal Cortex / Q000502:physiology*; D012559:Schizophrenia / Q000235:genetics; D055815:Young Adult
D002394:Catechol O-Methyltransferase