Objective: To examine the effects of melatonin and cortistatin on the damage caused by cellulosic thinner in the rat nucleus accumbens due to chronic inhalation at the biochemical and histological level. Methods: Research ventilation was done in special glass cages at constant temperature and pressure. In our study, 50 young male Wistar rats of Rattus norvegicus species weighing approximately 400-45 g were used. The rats were divided into 5 groups. Groups; control group, thinner group, thinner and cortistatin group, thinner and melatonin group, and thinner, melatonin and vitamin C group. There were 10 rats in each group and the rats were exposed to thinner inhalation in glass cages with air ventilation for 1 hour, 2 times a day for 6 weeks. At the end of the experiment, the animals were sacrificed and tissue and blood analysis was performed. Results: The first clinical manifestations of rats exposed to thinner inhalation were observed as subjects lying on top of each other, trying to hide their faces, and a tendency to flee to the corners of the glass cage. As the thinner application time increased, excessive licking, frequent blinking, drooling, shortness of breath, and inability to balance were observed in rats. On the eighth day of thinner inhalation, yellowing of body hair occurred in the subjects. It was determined that this yellowing continued throughout the entire experiment. We found that the body weights of the rats who inhaled thinner were significantly decreased compared to the rats who did not inhale the thinner (p<0.05). The histology of the nucleus accumbens tissue taken at the end of the experiment is as follows: In hematoxylin-eosin staining; The cells in the nucleus accumbens in the control group were compared with the cells of the thinner inhaled, thinner + cortistatin, thinner + melatonin and thinner + cortistatin + melatonin group. Biochemical analysis; Catalase Enzyme Activity, Glutathione Peroxidase Enzyme Activity Detection, Superoxide Dismutase Activity Detection were performed. Blood was taken from the aorto abdominalis of the subjects and liver enzyme activity determination was made ALT, AST, GGT and LDH. Conclusion: After thinner inhalation, damage occurred in the nucleus accumbens, and it was determined that the application of melatonin and cortistatin was preventive at the biochemical and histological level against this damage. [ABSTRACT FROM AUTHOR]