Vulnerability to Nicotine Addiction Can Be Predicted by Eye Blink Rates
A group of researchers led by NAKANO Tamami , Associate Professor, Dynamic Brain Network Laboratory, Graduate School of Frontier Biosciences, Osaka University, in joint research with Kyoto University, made a breakthrough discovery: Individual differences in spontaneous eye blink rate can be explained by genetic variation in the nicotinic receptor which binds to acetylcholine, a major neurotransmitter in the brain.
It is known that genetic polymorphism of nicotine receptor is related to the tendency to develop nicotine addiction from cigarette smoking. Predicting the tendency to develop nicotine addiction through spontaneous eye blink rates can be used as a biomarker.
Spontaneous eyeblink rates greatly vary among individuals from several blinks to a few dozen blinks per minute. Because dopamine agonists immediately increase the blink rate, individual differences in blink rate are used as a behavioral index of central dopamine functioning. However, an association of the blink rate with polymorphisms in dopamine-related genes has yet not been found. In this study, we demonstrated that a genetic variation of the nicotinic acetylcholine receptor CHRNA4 (rs1044396) increased the blink rate while watching a video. A receiver operating characteristic analysis revealed that the blink rate predicts a genetic variation in the nicotinic receptor gene with a significant discrimination level (0.66, p < 0.004). The present study suggests that differences in sensitivity to acetylcholine because of the genetic variation of the nicotinic receptor are associated with individual differences in spontaneous eye blink rate.
To learn more about this research, please view the full research report entitled " Association of a nicotinic receptor gene polymorphism with spontaneous eyeblink rates " at this page of the Nature website.