Reduced Thalamus Volume May Reflect Nicotine Severity in Young Male Smokers

Nicotineacts as an agonist at presynaptic nicotinic acetylcholine receptorsand to facilitate synaptic release of several neurotransmitters including dopamine and glutamate. The thalamushas the highest density of nicotinic acetylcholine receptorsin the brain, which may make this area more vulnerable to the addictive effects of nicotine. However, the volume of thalamusabnormalities and the association with smoking behaviors in young smokers remains unknown.Thirty-six young male smokers and 36 age-, gender- and education-matched nonsmokers participated in the current study. The nicotine dependenceseverity and cumulative effect were assessed with the Fagerstrom test for nicotine dependence(FTND) and pack-years. We used subcortical volume analyses method in FreeSurfer to investigate the thalamusvolume differences between young smokers and nonsmokers. Correlation analysis was used to investigate the relationship between thalamusvolume and smoking behaviors ( pack-yearsand FTND) in young smokers.Relative to nonsmokers, the young smokers showed reduced volume of bilateral thalamus. In addition, the left thalamusvolume was correlated with FTND in young smokers. It is hoped that our findings can shed new insights into the neurobiology of young smokers.In this article, we investigated the changes of thalamusvolume in young male smokers compared with nonsmokers. Reduced left thalamusvolume was correlated with FTND in young smokers, which may reflect nicotineseverity in young male smokers.