RESUMO
BACKGROUND: Apolipoprotein ε4 allele (APOE4) is the strongest genetic risk factor for Alzheimer's disease and seems to be related to cognitive decline and damaged event-related potential P300, which is a sensitive measure to assess cognitive processing. OBJECTIVE: This research aims to critically review the existing scientific evidence regarding the association between APOE4 and P300. METHODS: A systematic review was carried out up to January 2020 on the following databases: Web of Science, Scopus and Medline/PubMed. Articles were considered for inclusion if they are original research that provided information regarding the association between APOE4 and P300, available in English, Spanish, or Portuguese, and available in full text. The methodological quality of the studies selected was evaluated using the quality assessment tool for observational cohort and cross-sectional studies recommended by Cochrane. RESULTS: Out of 993 studies, 14 met the inclusion criteria. The results obtained showed that APOE4 is related to a longer P300 latency. However, the data supplied do not allow us to confirm if this relationship also occurs in amplitude measures. Moreover, it was observed that APOE genotype may influence P300 in different ages, from younger individuals to demented older people. CONCLUSION: Evidence shows that APOE4 negatively influences cortical activities related to cognitive functions, as indicated by P300.
Assuntos
Doença de Alzheimer , Apolipoproteína E4 , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Estudos Transversais , Eletroencefalografia , Potenciais Evocados P300/genética , HumanosRESUMO
OBJECTIVES: The present study was designed to investigate the association between the DRD4 genotype and auditory P300 amplitudes in a high-risk community sample. METHODS: ERPs were elicited in 197 eight-year-olds (98 boys, 99 girls) using a passive and an active oddball task. Auditory stimuli of 60 dB HL were presented binaurally at 1000 (standard stimulus) and 2000 Hz (target stimulus), at a relative frequency ratio of 80:20. Two trial blocks of 250 stimuli each were collected. P300 amplitudes were analyzed from Fz, Cz and Pz. DNA was genotyped for the DRD4 exon III polymorphism. RESULTS: A pattern of significant interactions of the DRD4 genotype with gender and experimental conditions was obtained. In both the active and the passive task, boys with at least one copy of the DRD4 7-repeat allele displayed significantly lower P300 amplitudes during the second trial block than boys carrying other alleles. CONCLUSIONS: This finding provides further evidence supporting a role of P300 amplitude reduction as an endophenotype for disinhibited psychopathology.