The influence of a serotonin 2A receptor gene (HTR2A) on stress responsivity.

The influence of a serotonin 2A receptor gene (HTR2A) on stress responsivity.

A single nucleotide polymorphism on the serotonin 2A receptor gene HTR2A (rs6313) alters neurological functions. Previous research has shown that the “A” allele carriers are at greater risk for increased stress responsivity. It is currently uncertain the extent to which rs6313 affects physiological and psychological responses. To address this uncertainty, we carried out a study with the hypothesis that “A” allele carriers on the serotonin 2A receptor gene would have increased physiological and psychological stress responsivity. The groups did not differ on any self-report measures of anxiety or sensation seeking. There was no difference between the groups on cortisol before or after the CPT. In agreement with previous research, there were differences between the groups on measures of autonomic arousal Relative to GG homozygotes (mean = 65, SD = 9.3), A allele carriers had a higher heartrate 1 minute after the CPT stress (mean = 71, SD = 12.62), t(1, 73)=2.30, p = 0.02. Our biomarker of autonomic arousal (sAA) was also higher in the A allele carriers (mean = 99, SD = 68.8) relative the GGs (mean = 66, SD = 61.5), t(1, 74)=2.06, p = 0.04 prior to the CPT stress and one minute after the CPT stressor A allele carriers (mean = 116, SD = 77) relative the GGs (mean = 78, SD = 78.5), t(1, 74)=2.03, p = 0.04. The groups were not significantly different from each other after 10 minutes. The findings suggest an increase in autonomic arousal in “A” allele carriers without psychological impact.