Some UW-Madison students do risky things in the winter, like plunging into an ice-cold lake for charity or flying down Observatory Hill on a lunch tray with no regard for their safety. According to a recent study, their thrill-seeking behavior could be linked to their genes.
Jim Olson of Seattle's Fred Hutchinson Cancer Institute and a team of scientists found a gene called neuroD2 that may be involved in mediating risky behavior. NeuroD2 is involved in the formation of the amygdala, a part of the brain that works with emotions and sensing danger, according to ScienCentral. Stephen Gammie, UW-Madison assistant professor of zoology, described one of the important features of the amygdala.
This is a brain region that's involved in consolidating fear memories,\ Gammie said. ""It's not just your regular memories, but it's memories that might be associated with something very negative.""
Gammie said memories such as seeing a menacing snake activate the region and cause you to jump or react in some way.
ScienCentral News reported Olson modified mice to have either no neuroD2 gene or have one out of the two copies that normal mice have. Olson's team watched the behavior of the mice on an elevated metal platform. Non-modified mice would normally want to be hidden in the dark or against walls, but Olson found modified mice went onto the metal platform that offered no protection just as often as staying in a safe place. Olson told ScienCentral News that more adventurous behavior was especially prevalent in the mice that lacked neuroD2 entirely.
Like mice, humans have genes that might be associated with fear.
""Humans have small differences in gene sequences or express higher or lower levels of a gene than other humans,"" Olson said in an e-mail to The Daily Cardinal. ""If a human expresses a lower level of the gene, it could be analogous to the neuroD2 heterozygous mice, which lack one copy of the gene and thus express lower levels [of fear]."" To study fear in humans, Olson said research must determine if fearlessness, altered perception of risks or changes in the function of the amygdala correlate with differences in DNA.
While some research shows neuroD2 is connected to fear, Gammie said that people should not be too quick to label it the ""fearless"" gene.
""All we know is that if we get rid of [the gene] it changes behavior,"" Gammie said. ""But that's usually a good enough criteria for us to want to jump on something and see how interesting it is."" Gammie explained that the study has not delivered a big breakthrough as of yet, but has potential that usually leads to further groundbreaking research beyond what just taking the gene away can do.
Perhaps scientists should go back and look at alumni who have plunged into frozen lakes or cascaded down Observatory during snowfalls to see if their children share the same thirst for the Wisconsin extreme.\
