Development and Validation of A Cost-effective Passive Avoidance Apparatus for Assessing Memory Impairments in Mice

Background: The passive avoidance (PA) test is commonly used to evaluate memory performance in rodents; however, the high cost of commercial apparatus limits its accessibility for neuroscience research. Methods: This study aimed to develop a cost-effective PA apparatus integrated with custom software for automated step-through latency measurement. To validate the system, a scopolamine-induced amnesia model was established using repeated regimens (1 mg/kg, i.p.) daily for six consecutive days. Result: A total apparatus development cost is approximately 450 USD, with the integrated software enabling heatmap visualizations of animal movement. During the retention trial, scopolamine-treated mice exhibited significantly shorter step-through latencies than saline-treated controls, indicating impaired memory retrieval. The automated measurements were consistent with manual timing, suggesting the accuracy and reliability of the apparatus. Histopathological analysis revealed marked cell loss in the hippocampus of scopolamine-treated mice, accompanied by reduced brain-derived neurotrophic factor (BDNF) expression. These findings confirmed successful induction of neurodegeneration and supported the memory deficits detected by the apparatus. Overall, the developed PA system offers a reliable and affordable platform for memory assessment in laboratory mice, particularly in resource-limited settings.