Tuesday, February 11, 2014

Genetic predisposition of our behavioral responses.

Gregory sets the context for a recent article by Skuze et al. on how genes for our oxytocin receptors can influence our social recognition skills:
...the notion that the evolution of our behavioral response is solely shaped by the events themselves is challenged by studies that highlight how interindividual differences in social perception and response to social cues may be determined by underlying genetic predisposition. These studies are establishing that our DNA contains heritable variants that contribute to subtle differences in social cognition. These sequence variants are contained within genes that not only play a role in the relationship that parents may have with their offspring but also how we recognize or react to one another. In PNAS, Skuse et al.investigate the signaling pathways of neuropeptides oxytocin (OT) and arginine-vasopressin (AVP) to identify DNA polymorphisms that might explain interindividual differences in response to social cues. The authors genotyped a series of SNPs from the OT and AVP receptor regions to identify SNPs that account for variation in response to tests of social cognition in autism spectrum disorder (ASD) families.
Here is the Skuze et al. abstract:
The neuropeptides oxytocin and vasopressin are evolutionarily conserved regulators of social perception and behavior. Evidence is building that they are critically involved in the development of social recognition skills within rodent species, primates, and humans. We investigated whether common polymorphisms in the genes encoding the oxytocin and vasopressin 1a receptors influence social memory for faces. Our sample comprised 198 families, from the United Kingdom and Finland, in whom a single child had been diagnosed with high-functioning autism. Previous research has shown that impaired social perception, characteristic of autism, extends to the first-degree relatives of autistic individuals, implying heritable risk. Assessments of face recognition memory, discrimination of facial emotions, and direction of gaze detection were standardized for age (7–60 y) and sex. A common SNP (single nucleotide polymorphism) in the oxytocin receptor (rs237887) was strongly associated with recognition memory in combined probands, parents, and siblings after correction for multiple comparisons. Homozygotes for the ancestral A allele had impairments in the range −0.6 to −1.15 SD scores, irrespective of their diagnostic status. Our findings imply that a critical role for the oxytocin system in social recognition has been conserved across perceptual boundaries through evolution, from olfaction in rodents to visual memory in humans.

1 comment:

  1. I feel that the researchers missed an opportunity to improve their findings. The researchers may have been able to improve their assessment of the autism-related genetic contribution to the study’s findings by separating the degree of environmental influence on the oxytocin receptor gene expression, as did a 2015 University of Virginia study.

    The fact that they sampled non-autistic siblings of autistic children may have made an assessment of epigenetic DNA methylation of the oxytocin receptor gene more compelling.

    Interestingly, both studies gave their subjects similar facial emotion recognition tests, with the current one deriving from findings about autism, and the second from findings about the amygdala.