بر اعتياد به مورفين در رت VTA بررسي اثر تحريك الكتريكي ناحيه تگمنتوم شكمي

Effects of electrical stimulation of ventral tegmental area on morphine addiction in rat

Background and aim: Ventral tegmental area (VTA) is located in the mesencephalon and it is one of the main nuclei that play a major role in drug abuse or addiction. In this study we investigated the effect of electrical stimulation of the VTA on addiction to morphine. Methods: Intravenous self-administration was used to quantify the level of drug-dependence. Twenty-four Wistar rats were divided into three groups: 1) Sham or saline group that had surgery and received saline by self administration. 2) Control or morphine group that had surgery and received morphine by self-administration. 3) Case or morphine + stimulation (25 }tA; 100 Hz; 0.14 ms period; for 10 minutes) group that had surgery and received electrical stimulation 15 minutes before morphine self-administration. Results: Addiction was seen only in the morphine group, and electrical stimulation of the VTA prevented the addiction. Conclusion: Electrical current stimulates all type of the neurons in the VTA. Since dopaminergic neurons comprise two-third of its neurons, VTA stimulation may cause the release of dopamine in the nucleus accumbence and produce rewards so that the animal needs no further rewards from morphine.