Table 1.
Rodent models of empathy, along with species tested, main behavioral findings, as well as any other manipulations performed and neurobiology discovered with each model.
| Model of Empathic Behavior | Species Studied | Outcome |
|---|---|---|
| Emotional Contagion - Behaviors | ||
| Church et al., 1959 | rats | Attenuation of operant behavior once it became associated with aversive shock to a conspecific |
| Langford et al., 2006 | mice | Potentiation of pain-related behaviors tested in the presence of a familiar conspecific that also received painful stimulus |
| Smith et al., 2016 | mice | Hyperalgesia observed in a “bystander” animal tested in the same environment as a conspecific that received painful stimulus, even without the shared experience of the stimulus |
| Carnevali et al., 2017 | rats | |
| Li et al., 2018 | rats | Prosocial behaviors (allo-licking and -grooming) made by “bystander” directed at conspecific that received noxious stimulus |
| Du et al., 2019 | rats | |
| Li et al., 2014 | rats | Expression of emotional contagion may be modulated by circulating glucocorticoid levels, depending on the type/severity of noxious stimuli used |
| Martin et al., 2015 | mice | |
| Laviola et al., 2017 | mice | Low levels of emotional contagion (paw licking) correlated with potentiated oxytocin and vasopressin levels in behaviorally-relevant brain areas absent any changes in receptor density. Low emotional contagion also associated with impaired reactivity to external stressors |
| Emotional Contagion – Brain Areas Associated | ||
| Li et al., 2014 | rats | Prefrontal cortex (PFC) |
| Knapska et al., 2006 | rats | PFC and amygdala |
| Zaniboni et al., 2018 | mice | Insula |
| Observational Fear Learning - Behaviors | ||
| Bredy and Barad, 2009 | mice | Context-dependent modulation of the social transmission of fear learning to an observer from a conspecific |
| Guzman et al., 2009 | mice | |
| Bruchy et al., 2010 | rats | |
| Knapska et al., 2010 | rats | |
| Atsak et al., 2011 | rats | |
| Jeon and Shin, 2011 | mice | |
| Sanders et al., 2013 | mice | |
| Jeon et al., 2010 | mice | Vicarious freezing behavior due to affective transfer to observer from conspecific receiving footshocks |
| Jeon and Shin, 2011 | mice | |
| Hernandez-Lallement et al., 2020 | rats | Instrumental harm aversion tested when observers became directly responsible for the footshock of the conspecific. This behavior was shown to be subject to effort |
| Guzman et al., 2009 | mice | Social buffering, both passive and active, modulated observational fear learning in observer. This phenomenon is dependent on the level of familiarity with the fearful conspecific |
| Watanabe 2011; 2015 | mice | |
| Kiyokawa et al., 2014 | rats | |
| Pisansky et al., 2017 | mice | Oxytocin administration, or chemogenetic activation of oxytocin neurons in the paraventricular nucleus of the hypothalamus (PVN), causes enhanced sensitivity to distress of the conspecific |
| Guzman et al., 2014 | mice | Oxytocin infusion into Lateral septum (LS) accelerated social buffering of observational fear |
| Observational Fear Learning - Brain Areas Associated | ||
| Pisansky et al., 2017 | mice | PVN |
| Guzman et al., 2014 | mice | LS |
| Jeon et al., 2010 | mice | Anterior cingulate cortex |
| Carrillo et al., 2019 | rats | |
| Restraint Stress Model - Behaviors | ||
| Bartal et al., 2011 | rats | Animals learn to release a conspecific from a restraint tube |
| Ueno et al., 2019a | mice | |
| Bartal et al., 2014 | rats | Release of a conspecific is modulated by social experience and familiarity |
| Ueno et al., 2019b | mice | Underlying motivation for release behavior in mice is less clear and may be driven by social interest and curiosity with the apparatus |
| Blystad et al., 2019 | rats | Release behavior may be modulated or dependent on contents of the container |
| Silberberg et al., 2014 | rats | Release behavior may be modulated or dependent on social contact |
| Carvalheiro et al., 2019 | rats | Release behavior may be modulated or dependent on alternative choices afforded to the observer |
| Bartal et al., 2011 | rats | |
| Bartal et al., 2016 | rats | Midazolam administered to observers before the session reduced door openings |
| Restraint Stress Model – Brain Areas Associated | ||
| Tomek et al., 2020 | rats | Insula |
| Soaked Conspecific Model - Behaviors | ||
| Sato et al., 2015 | rats | Animals learn to release a “soaked conspecific” into a dry chamber. Release behavior specific to presence of conspecific, and previous experience in the distressing condition potentiates the helping behavior |
| Cox and Reichel, 2019 | rats | |
| Mild stress (footshock) reduces latency to release distressed conspecific | ||
| Karakilic et al., 2018 | rats | |
| Yuksel et al., 2019 | mice | 8 weeks of voluntary wheel running improved door opening latency in females |
| Yamagishi et al., 2019 | rats | Oxytocin injections enhanced early acquisition of helping behavior in single-housed, but not pair-housed rats |
| Ueno et al., 2019b | mice | Oxytocin had no effect on door opening |
| Kandis et al., 2018 | rats | Dose-response relationship observed between acetaminophen concentration administered and reduction in door opening latency |
| Targeted Helping Independent of Social Interaction-Behaviors | ||
| Cox and Reichel, 2019 | rats | Rats will release distressed conspecific from a pool of water independent of social interaction. Release behavior is specific to a distressed conspecific, modulated by previous experience, and is dependent on effort |