Addictive effects of nicotine on rat cerebral cortex

Introduction: The most important alkaloid compound in tobacco is nicotine. Around 30% of the people in different countries are addicted to nicotine. Nicotine is also the leading cause of smoking. Prefrontal is part of the cerebral cortex that plays a pivotal role in personality and mental state. It is considered the main cause of addiction as it is
located in mesocorticolimbic dopamine system. However, with regard to the significant role of prefrontal cortex, no study has been conducted on the effects of nicotine on
morphological changes in prefrontal cortex region, so far. Thus, we purpose to investigate the addictive effects of nicotine on rat cerebral cortex.
Methods: Twenty four male rats were divided into four groups based on nicotine administration dose (0, 0.5, 1 and 1.5 g/kg). After animals were anesthetized, their
brains were fixed using transcardiac method. Tissue processing and Golgi staining were performed and the stained tissue sections were analyzed by optic microscope and Motic software. The data were analyzed using SPSS software.
Results: By increasing the dose, nicotine significantly decreased the number of neuronal processes. In the higher dose, nicotine caused a significant decrease and increase in the size of pericarions and dendritic spines, respectively (P<0.05).
Conclusion: Nicotine administration can decrease the size of pericarion and number of dendritic spines in the prefrontal cortex.