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Sonia Cavigelli"Individual differences in behavorial inhibition in rats"

Abstract :


Approximately 20% of children tested in the USA are categorized as behaviorally inhibited – i.e. they show motor inhibition in response to novel physical and social situations (Garcia-Coll et al. 1984).
This behavioral response to novelty is a stable trait for some and has been identified as a potential risk factor for certain health trajectories in adulthood. Behaviorally-inhibited children have an increased risk for allergies and anxiety disorders in adulthood, and older adult that identify themselves as ‘non-curious’ have an increased mortality rate (Bell et al. 1990, Kagan et al. 1991, Hirschfeld et al. 1992, Swan & Carmelli 1996, Kagan & Snidman 1999, Cox et al. 2005). These health differences may relate to different physiological profiles between inhibited and non-inhibited individuals. Behaviorally-inhibited children and adults experience a suite of physiological response biases associated with increased fear: elevated blood pressure responses to novelty, elevated glucocorticoid production, and elevated amygdala activity in response to novelty (Kagan et al. 1987, Schmidt et al. 1997, Bell et al. 1993, Schwartz et al. 2003). To better understand the development of this trait over the life span and to conduct experimental studies on the development and physiology of this trait, we have developed an animal model of behavioral inhibition (Cavigelli 2005). Results of our work indicate this trait can be modeled in rats, and that this model may provide a useful tool to better understand differential health and aging outcomes in inhibited vs. non-inhibited. To identify stably inhibited (or neophobic) rats, we test them in several novel conditions to identify those that regularly have longer than median approach latencies across different novel situations. We have shown that these stably inhibited rats have elevated blood pressure responses, elevated glucocorticoid production and increased anxiety-related behavior in adulthood (Cavigelli et al. 2007, Ragan et al. 2007). In addition, we find significant life span differences between inhibited and non-inhibited rats, with median life span differences of 3-8 months – which represents a difference of approximately 15-35% of the average life span in these animals (Cavigelli & McClintock 2003, Cavigelli et al. 2006, Cavigelli et al. in press). I will discuss future studies to further understand the development and physiology of this trait in rats, as a model of human behavioral inhibition

Selected publications

Cavigelli SA, Stine MM, Kovacsics C, Jefferson A, Diep MN, Barrett CE (2007). Behavioral inhibition and glucocorticoid dynamics in a rodent model. Physiol. Behav. [Epub ahead of print]
Cavigelli SA, Bennett JM, Michael KC, Klein LC (in press). Female temperament, tumor development and life span: Relation to glucocorticoid and TNFα levels in rats. Brain Behav. Immunity
Cox BJ, MacPherson PS, Enns MW (2005). Psychiatric correlates of childhood shyness in a nationally representative sample. Behav. Res. Ther. 43: 1019-27.

Pierre Mormede Labo PsyNuGen