title: Preservation of general intelligence following traumatic brain injury: contributions of the Met66 brain-derived neurotrophic factor.
abstract: Brain-derived neurotrophic factor (BDNF) promotes survival and synaptic plasticity in the human brain. The Val66Met polymorphism of the BDNF gene interferes with intracellular trafficking, packaging, and regulated secretion of this neurotrophin. The human prefrontal cortex (PFC) shows lifelong neuroplastic adaption implicating the Val66Met BDNF polymorphism in the recovery of higher-order executive functions after traumatic brain injury (TBI). In this study, we examined the effect of this BDNF polymorphism on the preservation of general intelligence following TBI. We genotyped a sample of male Vietnam combat veterans (n = 156) consisting of a frontal lobe lesion group with focal penetrating head injuries for the Val66Met BDNF polymorphism. Val/Met did not differ from Val/Val genotypes in general cognitive ability before TBI. However, we found substantial average differences between these groups in general intelligence (≈ half a standard deviation or 8 IQ points), verbal comprehension (6 IQ points), perceptual organization (6 IQ points), working memory (8 IQ points), and processing speed (8 IQ points) after TBI. These results support the conclusion that Val/Met genotypes preserve general cognitive functioning, whereas Val/Val genotypes are largely susceptible to TBI.
authors.affiliation: Decision Neuroscience Laboratory, University of Illinois, Urbana, Illinois, United States of America ; Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, Illinois, United States of America ; Department of Internal Medicine, University of Illinois, Champaign, Illinois, United States of America ; Department of Psychology, University of Illinois, Champaign, Illinois, United States of America ; Department of Speech and Hearing Science, University of Illinois, Champaign, Illinois, United States of America ; Neuroscience Program, University of Illinois, Champaign, Illinois, United States of America.
authors.forename: Aron K
authors.initials: AK
authors.lastname: Barbey
authors.affiliation: Universidad Autónoma de Madrid, Fundación CIEN/Fundación Reina Sofía, Madrid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Colom
authors.affiliation: Decision Neuroscience Laboratory, University of Illinois, Urbana, Illinois, United States of America ; Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, Illinois, United States of America.
authors.forename: Erick
authors.initials: E
authors.lastname: Paul
authors.affiliation: Department of Psychology, University of Delaware, Delaware, Maryland, United States of America.
authors.forename: Chad
authors.initials: C
authors.lastname: Forbes
authors.affiliation: Department of Molecular Neuroscience, George Mason University, Virginia, United States of America.
authors.forename: Frank
authors.initials: F
authors.lastname: Krueger
authors.affiliation: Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Goldman
authors.affiliation: Traumatic Brain Injury Research Laboratory, Rehabilitation Institute of Chicago, Chicago, Illinois, United States of America.
authors.forename: Jordan
authors.initials: J
authors.lastname: Grafman
mesh_terms: D000368:Aged; D001930:Brain Injuries / Q000503:physiopathology / Q000523:psychology*; D019208:Brain-Derived Neurotrophic Factor / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007360:Intelligence; D008297:Male; D008715:Methionine / Q000737:chemistry*; D008875:Middle Aged; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine