Abstract: In recent years, there have been frequent cases of seizures among adolescents after using e-cigarettes, which has aroused deep concern about the potential health risks of excessive nicotine intake. Compared to adults, adolescents exhibit heightened sensitivity to nicotine’s reinforcing effects and greater tolerance to its adverse effects, which may lead to increased nicotine intake. Evidence indicates that nicotine possesses seizure potential. While clinical research mainly focuses on nicotine addiction, the impact of seizure-inducing doses of nicotine on adolescent brain development remains understudied. This study investigates the impact of intraperitoneal injections of nicotine at seizure-inducing doses on the brain structure and behavior of adolescent female rats. The results indicate that nicotine exposure leads to both short-term and long-term increases in gray matter volume in the hippocampal dCA1/DG regions of female rats. Additionally, nicotine exposure triggers short-term activation of microglia in the hippocampal dCA1 and dDG regions and a long-term decline in recognition memory function.

Key words: magnetic resonance imaging (MRI), nicotine, adolescence, hippocampus,, microglia