Social buffering in rats: prolactin attenuation of active interaction.

摘要: Previous research has identified that social partners buffer stress (Kikusui, Winslow, & Mori, 2006). Several mechanisms of this buffering effect are being (Kiyokawa, Kikusui, Takeuchi, 2004; Wilson, 2007 3). The purpose the current study was to use a rat model examine role touch by partner decrease responses when exposed conditioned emotional response (CER) stressor. In humans, occurs an internal need or environmental demand is viewed as threatening out one’s control (Clark, Rager, Calpin, 1997). Stressors often categorized either physical psychological. Physical defined threat based on harm, pain, capacity terminate life (Lovallo, This type experimentally induced in animal methods which include, but not limited to, restraint (Kant, Eggleston, Landman-Roberts, Kenion, Driver, Meyerhoff, 1985; Kant, Mougey, 1986; Orr, Bunnell, 1990; McKinley, Young, 2000; Klenerova, Sida, Hynie, Jurcovicova, 2001), forced swim (Greisen, Altar, Bolwig, Whitehead, Wortwein, 2005; Ma, Shipston, Morilak, Russell, 2005), and footshock (Huhman, Moore, 1995; Pitman, Natelson, Ottenweller, McCarty, Pritzel, Tapp, Maslova, Bulygina, Markel, 2003; Westenbroek, Ter Horst, Roos, Kuipers, Trentani, den Boer, Penka, Bond, Heinrichs, 2004). Psychological stressors situations perceived threatening, interpretation leads engagement regardless whether environment actually harmful et al, Psychological commonly such open-field exposure novel (Yelvington, Weiss, Ratner, Muir Pfister, Terranova, Cirulli, Laviola, 1999; 2000, 2001; Miserendino, Haile, Kosten, Pijlman, Wolterink, Van Ree, 2003), elevated plus maze (Belda, Marquez, Armario, Mueller, Dolgas, Herman, Nadal, fear (Van de Kar, Lorens, McWilliams, Kunimoto, Urban, Bethea, 1984; Przewlocka, Sumova, Lason, Zhu Onaka, 2003). Conditioned offers prior experience. Female animals rarely have been examined CER literature; conditioned-fear paradigm previously relied almost exclusively male rats Urbana, Richardson, Paris, Richardson-Morton, 1987; Hata, Handa, Guschwan, Goral, al., 1990). Therefore, one goal present include female sample testing learned prolactin stress. Previous found secretion increase both psychological (Telner, Merali, Singhal, 1982; Yelvington, Marti-Carbonell, Darbra, Garau, Sanz, Balada, 1993). Prolactin increases direct function stimulus intensities (Armario, Lopez-Calderon, Jolin, Castellanos, 1986). al. (1990) tailshock be more intense than immobilization, immobilization chamber without shock. Different same stressor indicate gradations response. For example, Kant colleagues sensitive increasing Pennington, 1983). Based these studies, were expected display differences across slight variations even stressor. Responses may alleviated support, allowing presence another act against threats (Bondi Picardi, 1999). Among squirrel monkeys large group, caged live boa constrictor did adrenocortical activities; however, experienced absence hormonal levels (Coe, Franklin, Smith, Levine, 1982). A similar stressor, with partner. Juvenile conspecific had significantly lower individually (Wilson, 2000). In study, appeared attenuate given conspecific. However, offered distraction from stressful environment. included condition object possibility. In addition possible distraction, active touch, important element 2001). previous juvenile allowed during though all able see, hear, smell Although indeed promote buffering, does know if necessary. That is, occurrence rely reciprocated animal, it simply tactile stimulation. exploration comfort stimulation provided living nonliving stimuli dates back Harlow’s (e.g., 1959). experimental euthanized conspecifics explore buffering. Live functioned received response. Increased confounded increased activity, activity associated (Marti-Carbonell, 1993; Similarly, application ventral hippocampus decreased ambulation (Alvarez Banzan, 1994). could particularly problematic, would offer alternative explanation for hypothesized reductions prolactin. analyze general freezing behaviors quantified. When subjects paradigm, subsequent exposures evoke freeze behavior anticipation Freezing allow engage behaviors. In pairing produce day testing. Experimental conditions consisted tested alone (Alone), paired (Object), recently (Euthanized), (Social). fifth never due shock atmosphere chamber. These experimentation served condition. Alone, Object, Euthanized show higher Control Social (rats interactive littermate) exhibit those Alone (animals alone). differ treatment conditions, enhanced