rTCT: Rodent Triangle Completion Task to Facilitate Reverse Translational Study of Path Integration.

Path integration is navigation in the absence of environmental landmarks and is a primary cognitive mechanism underlying spatial memory. Path integration performance is primarily assessed in humans using the Triangle Completion Task (TCT). In humans, TCT has shown promise for the early diagnosis of Alzheimer's disease. In rodents, however, path integration is assessed using a wide variety of tasks, but none of which currently provide a homologue for the TCT. As rodents are routinely used as preclinical models, homologous path integration tasks that result in comparable performance metrics between species are important. In the present study, we developed and tested a novel rodent version of the triangle completion task to enhance cross-species comparability of path integration performance. Rats were able to comprehend and perform the task. A group of Alzheimer's disease model rats (TgF344-AD) exhibited similar path integration performance to their wild-type littermates. This work establishes a novel rodent homologue of the triangle completion task, facilitating enhanced reverse translational study of human path integration.