The ability to recognize emotion is modulated by the aryl hydrocarbon receptor (AhR) variants in normal human adolescents

Abstract

Previous studies have implicated the role of aryl hydrocarbon receptor pathway variants in biological effects (e.g., endometriosis), but few studies have investigated the role of these variants in psychological effects (e.g., intelligence). The purpose of this study was to determine whether the polymorphisms in aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor repressor (AHRR), and aryl hydrocarbon receptor nuclear translocator (ARNT) genes are associated with the ability to recognize emotion in normal human subjects. A total of 56 junior high-school students (28 males and 28 females) participated in the study. Participants were asked to perform an emotional recognition task, in which they classify various emotional intensities of faces and voices into happy, angry, sad and neutral voices. We used happy, angry and neutral voices, as recorded by 4 adolescent actors. The emotional intensity of each voice was modulated into 6 grades (0, 20, 40, 60, 80, 100%) by means of morphing techniques. We selected the following SNPs (Single Nucleotide Polymorphisms): G/A (rs2066853) Arg554Lys in AHR, C/G (rs2292596) Pro185Ala in AhRR, and G/C (rs2228099) in ARNT. These polymorphisms were genotyped by real-time polymerase chain reaction (PCR) analysis on an ABI 7900HT (Applied Biosystems). HPLC water was used as a negative PCR control in each amplification. We found that individuals with the AhR G/G genotype showed lower sensitivities in recognizing emotions from both faces and voices, compared with those with A/G and A/A genotypes. Our data indicate that different haplotypes of aryl hydrocarbon receptor gene polymorphisms are involved in the development of sensitivity for emotion recognition in normal subjects.