Effects of HTR1A rs6295 polymorphism on emotional attentional blink.

People prone to mood disorders and anxiety typically show increased sensitivity to task­irrelevant stimulation signifying threat. Better knowledge about the brain mechanisms mediating this sensitivity as well as about individual inherited differences in how these mechanisms function is a precondition for developing improved vulnerability screening, resilience building and treatment methods. The chances to have affective disorders are known to depend, among other factors, on the functioning of the brain serotonin systems developed under influence from common genetic variability. However, the extent and directions of the effects of SNPs involved in serotonergic regulation on the propensity for suboptimal threat­sensitivity are poorly understood. This applies also to HTR1A rs6295 polymorphism. Assisted by our custom developed emotional attentional blink task, we found that nonclinical subjects carrying the G allele (compared to C allele homozygotes) had higher sensitivity to threat­depicting distractor stimuli, expressed as an increase in the blink magnitude. We also disrupted right­hemisphere dorsolateral prefrontal cortex by rTMS (repetitive transcranial magnetic stimulation) to look for the possible role of DLPFC (dorsolateral prefrontal cortex; known to be involved in cognitive control of responses to affective stimuli) in serotonergic regulation mediated by the HTR1A rs6295 polymorphism. No main effects or interactions with rTMS being involved were found.

Mineralocorticoid receptor haplotype, estradiol, progesterone and emotional information processing.

BACKGROUND: Carriers of MR-haplotype 1 and 3 (GA/CG; rs5522 and rs2070951) are more sensitive to the influence of oral contraceptives (OC) and menstrual cycle phase on emotional information processing than MR-haplotype 2 (CA) carriers. We investigated whether this effect is associated with estradiol (E2) and/or progesterone (P4) levels. METHOD: Healthy MR-genotyped premenopausal women were tested twice in a counterbalanced design. Naturally cycling (NC) women were tested in the early-follicular and mid-luteal phase and OC-users during OC-intake and in the pill-free week. At both sessions E2 and P4 were assessed in saliva. Tests included implicit and explicit positive and negative affect, attentional blink accuracy, emotional memory, emotion recognition, and risky decision-making (gambling). RESULTS: MR-haplotype 2 homozygotes had higher implicit happiness scores than MR-haplotype 2 heterozygotes (p=0.031) and MR-haplotype 1/3 carriers (p<0.001). MR-haplotype 2 homozygotes also had longer reaction times to happy faces in an emotion recognition test than MR-haplotype 1/3 (p=0.001). Practice effects were observed for most measures. The pattern of correlations between information processing and P4 or E2 differed between sessions, as well as the moderating effects of the MR genotype. In the first session the MR-genotype moderated the influence of P4 on implicit anxiety (sr=-0.30; p=0.005): higher P4 was associated with reduction in implicit anxiety, but only in MR-haplotype 2 homozygotes (sr=-0.61; p=0.012). In the second session the MR-genotype moderated the influence of E2 on the recognition of facial expressions of happiness (sr=-0.21; p=0.035): only in MR-haplotype 1/3 higher E2 was correlated with happiness recognition (sr=0.29; p=0.005). In the second session higher E2 and P4 were negatively correlated with accuracy in lag2 trials of the attentional blink task (p<0.001). Thus NC women, compared to OC-users, performed worse on lag 2 trials (p=0.041). CONCLUSION: The higher implicit happiness scores of MR-haplotype 2 homozygotes are in line with previous reports. Performance in the attentional blink task may be influenced by OC-use. The MR-genotype moderates the influence of E2 and P4 on emotional information processing. This moderating effect may depend on the novelty of the situation.

Genes for emotion-enhanced remembering are linked to enhanced perceiving.

Emotionally enhanced memory and susceptibility to intrusive memories after trauma have been linked to a deletion variant (i.e., a form of a gene in which certain amino acids are missing) of ADRA2B, the gene encoding subtype B of the α2-adrenergic receptor, which influences norepinephrine activity. We examined in 207 participants whether variations in this gene are responsible for individual differences in affective influences on initial encoding that alter perceptual awareness. We examined the attentional blink, an attentional impairment during rapid serial visual presentation, for negatively arousing, positively arousing, and neutral target words. Overall, the attentional blink was reduced for emotional targets for ADRA2B-deletion carriers and noncarriers alike, which reveals emotional sparing (i.e., reduction of the attentional impairment for words that are emotionally significant). However, deletion carriers demonstrated a further, more pronounced emotional sparing for negative targets. This finding demonstrates a contribution of genetics to individual differences in the emotional subjectivity of perception, which in turn may be linked to biases in later memory.

The DRD2 C957T polymorphism and the attentional blink--a genetic association study.

The attentional blink phenomenon (AB) describes a transient deficit in temporally selective visual attention regarding the processing of the second of two target stimuli in a rapid serial visual presentation (RSVP) task. The AB is a very prominent paradigm in the Cognitive Neurosciences that has been extensively studied by diverse psychophysiological techniques such as EEG or fMRI. Association studies from molecular genetics are scarce although the high heritability of higher cognitive functioning is proven. Only one seminal study reported an association between AB magnitude and the dopamine receptor D2 (DRD2) C957T polymorphism (Colzato et al., 2011). This functional polymorphism influences striatal D2 receptor binding affinity and thereby the efficacy of dopaminergic neurotransmission which is important for working memory and attentional processes. Colzato et al. (2011) reported that DRD2 C957T T/T-carriers exhibit a significant smaller AB than C-allele carriers. In the present study this influence of the DRD2 SNP on the AB could not be replicated in N=211 healthy participants. However, a significantly larger lag 1 sparing was observed for homozygous T/T-carriers. Moreover, carriers of at least one T-allele showed a significantly poorer performance in the identification of T1. In general, these results support the notion of a role of the dopaminergic system on the AB. However, as our results do not parallel previous findings the exact nature of this influence and its dependence on task parameters will have to be examined in further genetic association studies.