Lasting changes in social behavior and amygdala function following traumatic experience induced by a single series of foot-shocks

Social Fear Conditioning: A Novel and Specific Animal Model to Study Social Anxiety Disorder

“…However, when the extinction was performed 15 days after SFC, conditioned mice still showed social fear during extinction recall, indicating that the social fear sensitized over time. Previous studies also showed sensitization of fear responses over time after single or repeated foot-shock exposure (Siegmund and Wotjak, 2007;Mikics et al, 2008a), suggesting that the circuitry underlying the conditioned social fear not only remains stable, but may even strengthen over time. Moreover, the maintenance of social fear over both the short-and long-term not only offers the possibility to test medication with fast onset of action, such as benzodiazepines, but also with a delayed onset of action, such as antidepressants (Katz et al, 2006;Mitchell, 2006;Priest, 2006).…”

“…Previous studies have shown that foot-shock exposure alone decreased social investigation for both short-and long-term, however, only when assessed in a novel environment (Short and Maier, 1993;Haller and Bakos, 2002;Haller et al, 2003;Louvart et al, 2005;Leveleki et al, 2006;Siegmund and Wotjak, 2007;Mikics et al, 2008a, b). When social investigation was assessed in the home cage, no differences were found, suggesting that the former result is due to novelty-induced anxiety (Mikics et al, 2008a).…”

“…Social defeat is used both acutely-one defeat by a dominant male and chronically-repeated defeat by several dominant males (for reviews see Huhman, 2006;Yan et al, 2010). Foot-shock exposure is used as exposure to a single (Short and Maier, 1993;Siegmund and Wotjak, 2007) or to repeated foot shocks (Haller and Bakos, 2002;Louvart et al, 2005;Mikics et al, 2008a). Although social defeat and foot-shock exposure decrease social investigation, they also lead to behavioral alterations including increased general anxiety, depression, and impaired locomotion that might account for the observed social deficit (Denmark et al, 2010;Hollis et al, 2010).…”

“…Previous studies have shown that foot-shock exposure alone decreased social investigation for both short-and long-term, however, only when assessed in a novel environment (Short and Maier, 1993;Haller and Bakos, 2002;Haller et al, 2003;Louvart et al, 2005;Leveleki et al, 2006;Siegmund and Wotjak, 2007;Mikics et al, 2008a, b). When social investigation was assessed in the home cage, no differences were found, suggesting that the former result is due to novelty-induced anxiety (Mikics et al, 2008a). Shock exposure also increased general anxiety and decreased locomotion and exploratory behavior in the open field and EPM (Van Dijken et al, 1992;Bruijnzeel et al, 2001;Pijlman and van Ree, 2002;Kavushansky et al, 2009), indicating that the decreased social investigation observed after foot-shock exposure may rather be due to an increase in general anxiety.…”

“…Social anxiety/avoidance is presently induced using a number of paradigms, including the social defeat paradigm-used both acutely and chronically (for reviews see Huhman, 2006;Yan et al, 2010), and foot-shock exposure (Haller and Bakos, 2002;Louvart et al, 2005;Mikics et al, 2008a). However, these paradigms are rather unspecific with respect to the behavioral alterations they induce, as increased general anxiety, depression, and impaired locomotion were found to accompany the social avoidance (Denmark et al, 2010;Hollis et al, 2010).…”