2000). Habituation is likely mediated by diminution of central responses to the stressor; for example, activation of c-fos expression in the medial parvocellular PVN is markedly reduced in the PVN following repeated restraint stress (Girotti et al., 2006). Habituation limits the overall physiological impact of stress, in terms of effects of repeated stress on energy balance (i.e., minimal weight loss), adrenal function (i.e., no adrenal hypertrophy) and cumulative corticosterone exposure (small decrements in thymus weight, associated with small episodic increases in corticosterone exposure) (Flak et al., 2012).
