www.bio-protocol.org/e2053 Vol 6, Iss 23, Dec 05, 2016 DOI:10.21769/BioProtoc.2053 Copyright © 2016 The Authors; exclusive licensee Bio-protocol LLC. 1 Delayed Spatial Win-shift Test on Radial Arm Maze Simone N. De Luca, Luba Sominsky and Sarah J. Spencer* School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic, Australia *For corresponding: Sarah.Spencer@rmit.edu.au [Abstract] The radial arm maze (RAM) is used to assess reference and working memory in rodents. This task relies on the rodent’s ability to orientate itself in the maze using extra-maze visual cues. This test can be used to investigate whether a rodent’s cognition is improved or impaired under a variety of experimental conditions. Here, we describe one way to test spatial working and reference memory. This delayed spatial win-shift (DSWS) procedure on the RAM was adapted from Packard and White (1990). The win-shift component of the test refers to the alternation of baiting, or rewarding, arms during the trial and test phase. The rodent is required to hold spatial information both within the task and across a delay to obtain the food-pellet reward (Taylor et al., 2003b). This task measures the incidence and type of memory errors made by the rodent both in the training and test phases of the learning task. A working memory error (re-entry of an arm that has been baited) can occur in both phases of the task, whilst a reference memory error (entry into an arm that has been baited during the training phase and is no longer baited) can only occur during the test phase. Keywords: Delayed spatial win-shift (DSWS), Radial arm maze (RAM), Spatial working memory, Spatial reference memory, Trial phase, Test phase [Background] The radial arm maze (RAM) can be used to examine the effects of hippocampal and prelimbic cortex (PLC) damage, ageing, as well as a variety of pharmacological agents (Wenk, 2001; Taylor et al., 2003b; Floresco et al., 1997; Vann et al., 2003). The hippocampus is widely accepted to be involved in both spatial working and reference memory. Lesions to the hippocampus in rodents have shown impairments in the ability to perform memory tasks, including the RAM, involving spatial navigation (O'Keefe and Nadel, 1978; Morris et al., 1982). The PLC region of the rat prefrontal cortex, the approximate equivalent of primate dorsolateral region of the prefrontal cortex (Groenewegen, 1988), is also involved in spatial working memory (Robbins, 1990). Taylor et al. have demonstrated that rodents with lesions to the PLC make more spatial reference and memory errors compared to controls in the delayed spatial win-shift (DSWS) procedure on the radial maze (Taylor et al., 2003b). The traditional RAM studies an animal’s explorative behaviour during the task, particularly investigating working memory (Seamans et al., 1995). The adaptation of the task to include the DSWS element is a well- established procedure in the literature. This technique investigates the rats’ ability to retain spatial information both within the task and across a delay (Taylor et al., 2003b; Lapish et al., 2008; De Luca et al., 2016).