Table 1.

Examples of animal behaviors analogous to human behavioral phenotypes (BI/BE and irritability) for psychiatric risk

Human behavioral phenotype	Method/paradigm	Model/strain	Measured behavior in animal model	Example References
BI/BE	Novel social/nonsocial arena + juvenile reciprocal social interaction	Rats/Sprague-Dawley (outbred)	Longer latency to approach novelty, lower locomotion in both a novel social and nonsocial arena, more exploration of arena rather than following or sniffing unfamiliar rat (BI) Shorter latency to approach and higher locomotion in both a novel social and nonsocial arena, following, chasing, or sniffing unfamiliar rat (BE)	(Caruso et al., 2014; Cavigelli et al., 2007; Michael et al., 2020; Terranova et al., 1993)
	Novel social/nonsocial arena + open field, light/dark box, elevated plus maze, elevated zero maze	Mice/C57BL6 (inbred)	Longer latency to approach novelty, lower locomotion, less time spent in anxiogenic and interaction parts of the test apparatus (BI) Shorter latency to approach novelty, higher locomotion, more time spent in anxiogenic and interaction parts of the test apparatus (BE)	(Miao et al., 2019)
	Predator exposure paradigm	Rats/Sprague-Dawley (outbred)	Sum of freezing and hypervigilance: absence of locomotion (BI)	(Nanda et al., 2008; Qi et al., 2010)
	Non-spatial cue-based learned approach-avoidance paradigm	Rats/Long-Evans	High avoidance of conflict (BI) High approach of conflict (BE)	(Schumacher et al., 2018)
	Eyeblink conditioning	Rats/Wistar-Kyoto; Sprague Dawley	Wistar-Kyoto rats, an animal model of BI, show facilitated acquisition of the classically conditioned eyeblink response (CCER)	(Janke et al., 2015)
	Ultrasonic Vocalizations (USV)	Rats/Wistar	Increased isolation-induced ultrasonic vocalizations (BI) Decreased isolation-induced ultrasonic vocalizations (BE)	(Wöhr & Schwarting, 2008)
	Selective breeding (open field, light/dark box, elevated plus maze)	Rats/Bred “low responders” & bred “high responders”	Bred low responders (LR); decreased locomotion, increased latency to approach novelty, less time spent in anxiogenic parts of the test apparatus (BI) Bred high responders (HR); increased locomotion, decreased latency to approach novelty, more time spent in the anxiogenic sections (BE)	(Clinton et al., 2011, 2021; Flagel et al., 2010; McCoy et al., 2019; Piazza et al., 1991; Sanna et al., 2015, 2017; Simmons et al., 2012; Thiel et al., 1999)
Irritability	Frustrative non-reward (FNR); omission of expected reward	Fish/Atlanic Salmon Smolts (commercial strain, Aquagen AS)	Aggressive acts like charges, nips and chases elicited by delayed feeding	(Vindas et al., 2014)
	Frustrative non-reward (FNR); omission of expected reward	Mice/C57BL/6J	Increase in operant responding (lever presses/minute)	(Martín-García et al., 2015)
	Frustrative non-reward & threat/opponent confrontation	Rats/Lister, Long-Evans, Sprague-Dawley, Wister	Mice emit USVs in the same frequency in response to both frustrative non-reward and threat	(Knutson et al., 2002)