Social modeling of conditioned fear in mice by non-fearful conspecifics

Abstract

Social interactions with conspecifics markedly alter the neuroendocrine, behavioral and emotional responses to stressful events. Some of these effects involve observational learning and result in lasting changes of fear-motivated behavior. While most evidence reveals increased fearfulness after observation of fearful demonstrators (models) in a number of species, a few reports from human and non-human primates indicate that observational learning can also attenuate some forms of fear. In the present study, we set out to determine the effects of social modeling and observational learning on fear conditioning in the mouse. Observers were pre-exposed to a novel context in the presence of fearful (F group) or non-fearful (NF group) demonstrators. Mice of the F group acquired control levels of conditioned fear. On the other hand, mice of the NF group exhibited profound and persistent reduction of fear. The decrease of fear in NF observers was most likely due to context-specific impairments of fear conditioning, as revealed by selective effects on long- but not short-term contextual fear memory, and normal fear conditioning in response to a novel context or cue. The effect was lasting, but constrained by the shock intensity. Attenuation of fear conditioning resulting from interactions with non-fearful conspecifics was largely, but not entirely, mediated by vicarious learning. These findings identify an important social buffering process serving to prevent a lasting induction of fear in response to isolated, moderately intense stressful events.

Social factors modulate restraint stress induced hyperthermia in mice

“…In fear conditioning, conspecifics without fear have a buffering effect (Guzman et al, 2009;Houtepen et al, 2011, for example). In the present experiment, it might be expected that free cage mates in the social inequality condition would have such a social buffering effect, because they were not suffering stress.…”

Witnessing traumatic events causes severe behavioral impairments in rats

“…witnessing defeat. It is reported that rodents are capable of emotional contagion, social buffering and shared effect or empathy (Church, 1959; Zentall and Levine, 1972; Heyes, 1994; Galef and Giraldeau, 2001; Valsecchi et al, 2002; Kiyokawa et al, 2004; Carlier and Jamon, 2006; Guzman et al, 2009; Knapska et al, 2010; Atsak et al, 2011), suggesting that a rodent can be attuned by the affective state of a social partner (Church, 1959; Rice and Gainer, 1962; Langford et al, 2006). Relevant to this, effect of social support and enriched environment has been examined in the social defeat paradigm (Ruis et al, 1999; de Jong et al, 2005; Lehmann and Herkenham, 2011).…”

Co-learning facilitates memory in mice: A new avenue in social neuroscience

“…To date, an audience effect of social learning was repeatedly demonstrated on fear memory in rodents under several conditions (review Panksepp and Lahvis, 2011), where a mouse or rat (observer) expressed freezing by observing other subject that receives foot shocks (demonstrators) or, in contrast, reduced fear response by observing non-fearful conspecific (Guzmán et al, 2009). The great interest in observational fear memory in mice was increased recently after the first report of empathy that modulates a pain response in mice (Langford et al, 2006), since historically empathy was considered as a feature of the highest nervous system in humans.…”