Washington, Dec 23: Scientists, led by an Indian-origin researcher, have identified a gene that may determine the intensity of our response to cocaine.
Researchers at the University of Texas Southwestern suspect that the newly identified gene, Cyfip2, determines how mammals respond to cocaine, although it is too soon to tell what the indications are for humans or for addiction.
The findings evolved from examining the genetic differences between two substrains of the standard C57BL/6 mouse strain: a 'J' strain from the Jackson Laboratory (C57BL/6J) in US and an 'N' strain from the National Institutes of Health (C57BL/6N).
The study, with Dr Vivek Kumar as the lead author, compared the two strains of mice and used their differential responses to cocaine to identify the causative gene.
"We found that the 'N' strain has accumulated mutations over time, one of which has a very strong effect on cocaine response," said Dr Joseph Takahashi, chair of neuroscience and a Howard Hughes Medical Institute investigator at UT Southwestern and the senior author of the study.
"We propose that CYFIP2 - the protein produced by the Cyfip2 gene - is a key regulator of cocaine response in mammals," he said.
"We identified this gene by first using a forward genetics strategy to search for differences in traits between the two mouse strains. We found a difference in cocaine response between them, with the C57BL/6N strain showing a reduced behavioural response," Takahashi said.
"We then carried out genetic mapping and whole genome sequencing, which allowed us to pinpoint the Cyfip2 gene as the causative one in a rapid and unambiguous way," he added.
The study was published in the journal Science....