Table 1.

Representative examples of methods used for novel object recognition in mice. Column 1 lists the NICHD-supported Intellectual and Developmental Disabilities Rodent Core facilities that contributed information about standard methods which have been effective in their studies. Column 2 confirms that object pairs were pre-tested to ensure that the two objects, presented simultaneously, evoked equal amounts of exploration by control mice. Column 3 summarizes various protocols used for habituating subject mice to the test arena without objects present. Habituation is designed to reduce the time spent exploring arena surfaces during the novel object test phases. Procedures for habituation vary across facilities for many reasons, including properties of the testing environment and background strain of the subject mice. Column 4 displays the retention interval, i.e. the length of time between familiarization of the two identical objects and choice between the familiar and the novel object. Retention intervals are usually selected to evaluate aspects of short-term and long-term memory. Column 5 lists the statistical tests used to determine whether novel object recognition was significant, i.e. more time was spent exploring the novel mouse than the familiar object, for each genotype or for each treatment group. Choice of statistical test varies according to experimental design. Column 6 provides references for obtaining more detailed information about novel object recognition procedures used by reputable behavioral laboratories. Further descriptions of standard protocols and caveats for conducting novel object recognition assays appear in the text sections under “Strategies to Ensure Reproducibility.”

IDDRC site, Rodent Core Manager and/or Director	Were the two objects previously confirmed for equal valence? (Yes/No)	Prior habituation to the empty test chamber (# days, # minutes/day)	Interval between familiarization and recognition sessions (minutes, hours or days)	Data presentation and statistical analyses used	Reference(s)
UC Davis MIND Institute, Crawley	Yes 6 objects in use across studies, object pairs counterbalanced	30 minutes/day,1–4 days, varies by strain	1 hour or 30 minutes for short-term memory, 24 hours for long-term memory	Repeated Measures ANOVA; One Way ANOVA with Tukey’s posthoc for preference and discrimination indices; paired t-test for sniff times within-group	Gompers et al. (2017); Silverman et al. (2013); Stoppel et al. (2017); Yang et al. (2015)
Albert Einstein College of Medicine, Gulinello	Yes, 2 objects used, counterbalanced, validated	Usually 6 minutes, sometimes no habituation	1 hour-24 hours	ANOVA, Chi Square % preference and pass/fail rate	Dai et al. (2010); Vijayanathan et al. (2011)
UW Madison Waisman Center, Mitchell/Chang	Yes, 4 objects used, counterbalanced	Mice pre-handled by experimenter for at least 3 days, habituation to chamber is one 6-minute session	3 minutes	ANOVA	Hullinger et al. (2016)
UPenn, CHOP O’Brien/Abel	Yes	5 min/day, 3–5 days, varies by strain	1 hour for short-term memory, 24 hours for long-term memory	Two-way ANOVA for gene effect, drug effect, and gene × drug interaction, Tukey post- hoc	Oliveira et al. (2010); Patel et al. (2014)
Children’s National Medical Center, Wang/Corbin	Yes	15 minutes/day, 4 consecutive days	15 minutes, 6-hour interval	Two-Way Repeated Measures ANOVA, Newman-Keuls post-hoc	(Wang et al., 2011)
Baylor College of Medicine, Veeraragavan/Samaco	Yes	5 minutes/day,1–4 days	24 hours	One-Way ANOVA with LSD or Tukey’s posthoc, paired t-test	Lu et al. (2017)
Boston Children’s Hospital, Andrews/Fagiolini	Yes	Typically 5 minutes on day prior to first trial of same objects, sometimes no habituation	10 minutes, 24 hours, depending on mouse model	ANOVA, genotype × object between/within	Arque et al. (2008)
University of Washington, Cole/Burbacher	Yes	Habituation to room > 1 week; pre-handling 3–5 days; habituation to chamber 15–30 minutes, 1 day prior to testing.	1 hour, 48 hours	One-Way ANOVA or Two-Way ANOVA with Bonferroni’s post hoc	Choi et al. (2017); Pan et al. (2012); Wang et al. (2014)