WASHINGTON - A genetic variation in serotonin, a brain chemical, influences social behaviour of rhesus macaque monkeys, making them avoid risks or just play safe, a new study says.
Humans and macaques are the only members of the primate family to have this particular genetic trait. The finding could be the new model to study autism, social anxiety and schizophrenia.
‘We have found very similar gene-based disruptions in social rewards shared by monkeys and by humans,’ said Michael Platt, associate professor of neurobiology at Duke University Medical Centre.
Platt’s research group at Duke studied behaviour and social anxiety in two groups of monkeys with variations in the serotonin transporter gene, crucial to regulating emotion.
Based on earlier observations, scientists knew that humans carry two versions of the gene, long and short. Some people have two long versions (L/L), but the people with one of each (S/L) are known to experience a higher incidence of social anxiety and other such behaviour.
In a series of experiments, the short version of the gene in monkeys was found to influence their risk-taking when faced with particular social stimuli.
‘Based on work in humans, we interpreted this to reflect an induction of a fearful emotional state, which often leads people to become risk averse,’ said Karli Watson, of Duke’s Department of Neurobiology, a co-author on the paper.
In human populations of European ancestry, 48 percent are S/L and 36 percent are L/L. The rest are S/S. The S allele is more common in Asian populations, a Duke release cited Watson as saying.
‘Heightened sensitivity to social threats may prove to be helpful in many ways, because success in a social group depends on seizing opportunities while avoiding any potential harmful, antagonistic interactions,’ Watson said.
The study appeared in the online journal PLoS One Jan 13.