A Study On The Relationship Between The Polymorphisms In DDC,DRD4 And Human Cognitive Ability

Cognition is the most basic ability of human evolution to adapt and transform to the environment. Recently, the cognitive ability has become research hotspot of neurobiology and neuropsychology, and many stusies proved that neurobiology attributes of cognitive ability in the human brain are heritable and polygenic traits in regulatory. Previous studies on the relationship between receptors and enzymes in the dopamine neurotransmitter systems and cognitive ability suggested that some genes encoding receptors and enzymes in dopamine, may play an important role in human cognitions.This study selected dopamine D4 receptor gene (DRD4) and dopa decarboxylase gene (DDC) in zhe dopamine neurotransmitter systems.Four functional single nucleotide polymorphisms (SNPs) (rs6263, rs12666409, rs1800955, rs936461) and one genetic marker (rs11575375) in DDC gene and DRD4 gene were identified based on PCR-SSCP genotyping methods. At last data and statistical analysis were completed using Finetti and SPSS17.0 software package we explore the relationship of the 5 variants in the genes and working memory, central executive function, spatial cognitive ability, long-term memory, and verbal cognitive ability in a over 790 young healthy undergraduate students by the behavioral genomics method.Single factor variance analysis showed that rs6263 in DDC gene is significantly associated with reasoning error rates of verbal cognitive ability (p=0.028);rs11575375 is significantly associated with error rates of sentence-picture matching (p=0.005)and blocks connection(p=0.020); while rs12666409 shows no significant correlation with any type of cognitive tests (p> 0.05).rs1800955 in DRD4 gene is associated with digital memories ratio of long-term memory ability (p=0.046); rs936461 is significantly associated with updating of central executive function(p=0.017).The results of this study show that the the polymorphisms in DDC gene is associated with verbal cognitive ability and spatial cognitive ability in Chinese Han undergraduate students; the polymorphisms in DRD4 gene may selectively influence on long-term memory ability and the central executive function in man.