Differences in Spatial Memory Impairment in Mice after Oral D-Galactose Administration and Intraperitoneal Injection

BACKGROUND: The aging process can increase the incidence of dementia, such as spatial memory impairment to remember space, recognize shapes and distances. Research on dementia in mice was carried out by administering d-galactose through intraperitoneal injection, while oral d-galactose administration had not received enough attention. AIM: This study aims to prove the differences in the occurrence of spatial memory impairment in rats induced by d-galactose through two different routes, oral and intraperitoneal injection. METHODS: This study is an experimental study using a post- test control group design. The sample criteria were 20 male Wistar rats aged 12–14 weeks, weighing 200–300 g divided into two groups which are the oral and intraperitoneal injection. Spatial memory assessment based on spontaneous alternation using the Y-maze test was carried out at the end of week 8. RESULTS: In this study, the average spatial memory score after d-galactose administration in the injection group (51.572±4.388) was lower compared to the oral group (66.058±1.551). The Shapiro–Wilk normality test shows that the data are normally distributed with p > 0.05. Independent t-test showed a significant difference in the incidence of spatial memory disorders between the injection and oral groups with p = 0.010 (p < 0.05). CONCLUSION: The conclusion of this study is that d-galactose administration by oral route or intraperitoneal injection causes a decrease in spatial memory in mice. Spatial memory in the injection group was lower than in the oral group. This might be related to the decrease in synaptophysin in the hippocampus of mice due to d-galactose administration by intraperitoneal injection.