Early life stress induces long-term changes in limbic areas of a teleost fish: the role of catecholamine systems in stress coping

Abstract

Early life stress (ELS) shapes the way individuals cope with future situations. Animals use cognitive flexibility to cope with their ever-changing environment and this is mainly processed in forebrain areas. We investigated the performance of juvenile gilthead seabream, previously subjected to an ELS regime. ELS fish showed overall higher brain catecholaminergic (CA) signalling and lower brain derived neurotrophic factor (bdnf) and higher cfos expression in region-specific areas. All fish showed a normal cortisol and serotonergic response to acute stress. Brain dopaminergic activity and the expression of the α2Α adrenergic receptor were overall higher in the fish homologue to the lateral septum (Vv), suggesting that the Vv is important in CA system regulation. Interestingly, ELS prevented post-acute stress downregulation of the α2Α receptor in the amygdala homologue (Dm3). There was a lack of post-stress response in the β2 adrenergic receptor expression and a downregulation in bdnf in the Dm3 of ELS fish, which together indicate an allostatic overload in their stress coping ability. ELS fish showed higher neuronal activity (cfos) post-acute stress in the hippocampus homologue (Dlv) and the Dm3. Our results show clear long-term effects on limbic systems of seabream that may compromise their future coping ability to environmental challenges.

Early-life manipulation of cortisol and its receptor alters stress axis programming and social competence

“…Early exposure to cortisol and to mifepristone induced persistent changes in the expression of two main stress genes in the telencephalon, suggesting that glucocorticoid signalling in this brain area during later life will differ compared to control treatment fish [89]. The telencephalon is central for behavioural expression as it is involved in social decision-making [91,92] and cognitive processing of information [93]. In the following paragraphs, we discuss the long-term effects of cortisol and mifepristone, which suggest that both drugs may have temporarily increased fluctuating cortisol levels after the applications during early life.…”

“…Over recent years, evidence has been rapidly accumulating that the stress axis of vertebrates can be re-programmed early in life by social [11,16,91] and ecological [92,93] royalsocietypublishing.org/journal/rstb Phil. Trans.…”

Neurobiology of Wild and Hatchery-Reared Atlantic Salmon: How Nurture Drives Neuroplasticity

“…Within specific neuronal populations, the cfos gene is relatively little expressed at basal levels but when neurons are stimulated, cfos expression is rapidly increased with mRNA levels typically peaking between 15 and 30 min post activation ( Hoffman et al, 1993 ; Pavlidis et al, 2015 ). Acute stress can increase neuronal cfos expression in a variety of animals, including rats ( Cullinan et al, 1995 ; Rosen et al, 1998 ), zebrafish ( Danio rerio ; Pavlidis et al, 2015 ), gilthead seabream ( Sparus aurata ; Vindas et al, 2018 ) and Atlantic salmon ( Vindas et al, 2017 ). Our findings corroborate that acute stress increases cfos expression in the Dl, Dm, and Vv of teleost fish ( Vindas et al, 2017 , 2018 ).…”

“…For each section, the total number of transcript-labeled cells was counted in both the entire Dl and Dm, as well as within their respective dorsal and ventral subregions (Dld and Dlv, Dmd and Dmv), to elucidate subregion-specific expression patterns and to allow for comparisons with previous studies (e.g., Vindas et al, 2017 ). The number of labeled cells was quantified as described by Vindas et al (2018) and Moltesen et al (2016) . In short, the number of transcript-expressing cells was counted within each subregion for both lobes in each section (in which interest areas were found).…”

Genome-Wide Epigenomic Stress Response in the European Sea Bass (Dicentrarchus Labrax, L.)

“…In sh, cortisol binds the glucocorticoid receptor (gr) and controls BDNF expression in the brain. With gr and relatively few other genes, BDNF has thus emerged as one of the target genes of interest in stress studies, as shown for zebra sh [134], sea bream [135] and sea bass [86,[136][137][138]. BDNF is also involved in other aspects of the stress response in sh (e.g.…”