Prefrontal-hippocampal coupling during memory processing is modulated by COMT val158met genotype.
BACKGROUND
Studies in humans and in animals have demonstrated that a network of brain regions is involved in performance of declarative and recognition memory tasks. This network includes the hippocampal formation (HF) as well as the ventrolateral prefrontal cortex (VLPFC). Studies in animals have suggested that the relationship between these brain regions is strongly modulated by dopamine.


METHODS
Using fMRI in healthy humans matched for a series of demographic and genetic variables, we studied the effect of the COMT val158met polymorphism on function of HF and VLPFC as well as on their functional coupling during recognition memory.


RESULTS
The COMT Val allele was associated with: relatively poorer performance at retrieval; reduced recruitment of neuronal resources in HF and increased recruitment in VLPFC during both encoding and retrieval; and unfavorable functional coupling between these two regions at retrieval. Moreover, functional coupling during retrieval was predictive of behavioral accuracy.


CONCLUSIONS
These results shed new light on individual differences in responsivity and connectivity between HF and VLPFC related to genetic modulation of dopamine, a mechanism accounting at least in part for individual differences in recognition memory performance.
Bertolino
Alessandro
A
Psychiatric Neuroscience Group, Section on Mental Disorders, Department of Psychiatric and Neurological Sciences, University of Bari, Bari, Italy. bertolia@psiciat.uniba.it
Rubino
Valeria
V
Sambataro
Fabio
F
Blasi
Giuseppe
G
Latorre
Valeria
V
Fazio
Leonardo
L
Caforio
Grazia
G
Petruzzella
Vittoria
V
Kolachana
Bhaskar
B
Hariri
Ahmad
A
Meyer-Lindenberg
Andreas
A
Nardini
Marcello
M
Weinberger
Daniel R
DR
Scarabino
Tommaso
T
D000328:Adult; D000704:Analysis of Variance; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D006624:Hippocampus / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007206:Individuality; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008715:Methionine / Q000235:genetics*; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010100:Oxygen / Q000097:blood; D017397:Prefrontal Cortex / Q000098:blood supply / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D014633:Valine / Q000235:genetics*
D008715:Methionine; D002394:Catechol O-Methyltransferase; D014633:Valine; D010100:Oxygen