Constitutive differences in glucocorticoid responsiveness to stress are related to variation in aggression and anxiety-related behaviors

Constitutive differences in glucocorticoid responsiveness are related to divergent spatial information processing abilities

“…Importantly, we confirmed that the three lines display a stable divergence in CORT responsiveness to stressors from the juvenile period throughout aging and a behavioral phenotype comparable to the one reported in young-adults from the same lines (Walker et al, 2017; Walker and Sandi, 2018; Huzard et al, 2019). Our results show that, as compared to Inter line rats, rats from the High line were high CORT responders, and those from the Low line were low CORT responders to stressful challenges throughout life.…”

“…So far, our work with these lines of rats selected tor their differential CORT responsiveness to stressors has verified that differential hormonal levels implied by the selection procedure at juvenility are still maintained when animals are exposed to life challenges during early adulthood (Walker et al, 2017). Here, we tested animals during the aging process.…”

“…In fact, an age-related decline in the adrenal stimulated secretion of corticosterone has been earlier documented (Cizza et al, 1994; Hauger et al, 1994; Oh et al, 2018). Moreover, it is important to note that the High CORT line shows normal CORT baseline and recovery levels following stress activation, while it displays higher peak CORT levels following stress exposure and lower habituation to repeated stress (Walker et al, 2017). Therefore, this pattern of mounting a high CORT response to stress while being capable to efficiently recover CORT levels to normal baseline values might have allowed the optimal cognitive performance of the High line during all cognitive phases.…”

“…Based on the role of CORT in the facilitation of memory acquisition during training and on the inverted U-shape theory, we hypothesized that the Low line would present worse spatial information processing capacities as compared to the Inter line. Moreover, as the CORT elevation displayed by the High line in response to a stress challenge (Walker et al, 2017) does not reach the high CORT levels found to induce cognitive impairments in a Morris water maze task (Salehi et al, 2010), we hypothesized that the High line would benefit from the endogenous higher glucocorticoids response and display superior spatial information processing capacities (particularly long-term memory) as compared to the Low and Inter CORT lines. To gain insight into the effects of stress on spatial learning abilities, we expanded the analysis of the traditional parameters from the Morris water maze by implementing a novel classification method that captures detailed aspects of swimming performances and exploratory strategies (Gehring et al, 2015; Vouros et al, 2018).…”

Alterations in brain microstructure in rats that develop abnormal aggression following peripubertal stress

“…In line with our findings, repetitive stress has been found to have differential impact on brain structure in more vs. less stress responsive rat strains (Bourgin et al., ; Magalhaes, Barriere, et al., ; Magalhaes, Bourgin, et al., ). Nonaggressive PPS rats, that had greater corticosterone responses to peripubertal stress, displayed more anxiety‐like and less social behaviour, in accordance with the phenotype of recently developed high‐corticosterone rat lines (Walker & Sandi, ; Walker, Zanoletti, Guillot de Suduiraut, & Sandi, ). The brain regions studied here are particularly responsive to the programming effects of stress and are still maturing during the peripubertal period (Andersen & Teicher, ; Romeo, Kaplowitz, Ho, & Franco, ; Spear, ).…”