scholarly journals The effects of brain serotonin deficiency on behavioural disinhibition and anxiety-like behaviour following mild early life stress

2013 ◽  
Vol 16 (9) ◽  
pp. 2081-2094 ◽  
Author(s):  
Benjamin D. Sachs ◽  
Ramona M. Rodriguiz ◽  
William B. Siesser ◽  
Alexander Kenan ◽  
Elizabeth L. Royer ◽  
...  

Abstract Aberrant serotonin (5-HT) signalling and exposure to early life stress have both been suggested to play a role in anxiety- and impulsivity-related behaviours. However, whether congenital 5-HT deficiency × early life stress interactions influence the development of anxiety- or impulsivity-like behaviour has not been established. Here, we examined the effects of early life maternal separation (MS) stress on anxiety-like behaviour and behavioural disinhibition, a type of impulsivity-like behaviour, in wild-type (WT) and tryptophan hydroxylase 2 (Tph2) knock-in (Tph2KI) mice, which exhibit ∼60–80% reductions in the levels of brain 5-HT due to a R439H mutation in Tph2. We also investigated the effects of 5-HT deficiency and early life stress on adult hippocampal neurogenesis, plasma corticosterone levels and several signal transduction pathways in the amygdala. We demonstrate that MS slightly increases anxiety-like behaviour in WT mice and induces behavioural disinhibition in Tph2KI animals. We also demonstrate that MS leads to a slight decrease in cell proliferation within the hippocampus and potentiates corticosterone responses to acute stress, but these effects are not affected by brain 5-HT deficiency. However, we show that 5-HT deficiency leads to significant alterations in SGK-1 and GSK3β signalling and NMDA receptor expression in the amygdala in response to MS. Together, these findings support a potential role for 5-HT-dependent signalling in the amygdala in regulating the long-term effects of early life stress on anxiety-like behaviour and behavioural disinhibition.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Megan K Rhoads ◽  
Kasi C McPherson ◽  
Keri M Kemp ◽  
Bryan Becker ◽  
Jackson Colson ◽  
...  

Early life stress (ELS) is an independent risk factor for the development of cardiovascular disease in adulthood in both humans and rodent models. Maternal separation and early weaning (MSEW), a model of ELS, produces mice with an increased risk of cardiovascular dysfunction in adulthood, despite resting blood pressures (BP), heart rates (HR), and body weights comparable to normally reared controls. Autonomic regulation of HR and BP is an important component of the homeostatic response to stress but has not been investigated in MSEW mice. We hypothesized that exposure to MSEW impairs autonomic function at baseline and in response to an acute psychosocial stressor in adult male mice. C57Bl/6J litters were randomly assigned to MSEW or normally reared control conditions. MSEW litters were separated from dams for 4 h on postnatal days (PDs) 2-5, 8 h on PDs 6-16, and weaned at PD 17. Control litters were undisturbed until weaning at PD 21. At 9 weeks old, telemeters were implanted in MSEW (n=16) and control mice (n=12). During cage switch stress (CSS), mice were moved to a soiled, unfamiliar cage for 4 h. HR, systolic BP (SBP), diastolic BP (DBP), and activity (monitored by telemetry) were similar between control and MSEW mice at baseline and during CSS (p>0.05, 2-way ANOVA). Spectral analysis of HR, SBP, and DBP indicated that HR variability (HRV) total power was lower in MSEW mice during the 12 h inactive period compared to controls (18.9±1.1 ms 2 vs. 27.5±3.1 ms 2 ; p=0.0033, 2-way ANOVA) at baseline. HRV low frequency (LF) power was also lower during the 12 h inactive period in MSEW mice (4.2±0.4 ms 2 vs.6.6±0.9 ms 2 ; p=0.009). At baseline, 12 h and 24 h DBP variability LF/high frequency (HF) ratio, normalized LF, and normalized HF power were lower in the MSEW group (p<0.05, all comparisons). During the final 90 minutes of CSS, MSEW mice had lower HRV total, LF, and HF power compared to controls (p<0.05); although HR, SBP, DBP, and activity remained similar between groups. These data suggest that MSEW mice have impaired autonomic control of HR and DBP and lack the ability to robustly respond and recover from an acute stressor. Reduced responsiveness of the autonomic nervous system may contribute to the increased risk of cardiovascular disease development in adult mice exposed to MSEW.


Author(s):  
Helen Eachus ◽  
Min-Kyeung Choi ◽  
Soojin Ryu

The early life period represents a window of increased vulnerability to stress, during which exposure can lead to long-lasting effects on brain structure and function. This stress-induced developmental programming may contribute to the behavioural changes observed in mental illness. In recent decades, rodent studies have significantly advanced our understanding of how early life stress (ELS) affects brain development and behaviour. These studies reveal that ELS has long-term consequences on the brain such as impairment of adult hippocampal neurogenesis, altering learning and memory. Despite such advances, several key questions remain inadequately answered, including a comprehensive overview of brain regions and molecular pathways that are altered by ELS and how ELS-induced molecular changes ultimately lead to behavioural changes in adulthood. The zebrafish represents a novel ELS model, with the potential to contribute to answering some of these questions. The zebrafish offers some important advantages such as the ability to non-invasively modulate stress hormone levels in a whole animal and to visualise whole brain activity in freely behaving animals. This review discusses the current status of the zebrafish ELS field and its potential as a new ELS model.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Carolina Dalmasso ◽  
Jacqueline Leachman ◽  
Sundus Ghuneim ◽  
Nermin Ahmed ◽  
Jorge F Giani ◽  
...  

Male C57BL/6J mice exposed to maternal separation and early weaning (MSEW), a mouse model of early life stress, display increased blood pressure (BP) and sympathetic activation compared to obese controls when fed a high fat diet (HF). Moreover, HF-fed MSEW males display exacerbated BP responses to the acute stimulation of the adipose afferent reflex (AAR) in epididymal white adipose tissue (eWAT). The aim of this study was to investigate the contribution of endogenous factors that could stimulate fat sensory neurons. MSEW and control (C) mice (n=8/group) were placed on a LF or HF (10% and 60% Kcal from fat, respectively) for 16 weeks. Then, serum obtained by decapitation and adipose tissue samples were collected to measure mRNA and protein expression of 15 factors and receptors known to activate sensory neurons. No differences were found across measurements on LF. Plasma AGT and AngII were decreased in HF-fed MSEW compared to C (AGT: 760±48 vs. 1267±161 ng/ml, p<0.05; AngII; 413±57 vs. 1082±340 pmol/l, p<0.07, Attoquant) and no differences were found in leptin (103±6 vs. 104±4 ng/ml, p<0.87). In eWAT, MSEW and C showed similar AGT (2.1±0.4 vs. 1.9±0.3 ng/ml per g tissue), AngII (1.7±0.2 vs. 2.3±0.5 pg AngII/mg tissue), ACE 1 activity (21.5±1.2 vs. 20.0±0.9 RFU/min/μg protein, p<0.33) and leptin (102.8±6.1 vs. 104.5±6.8 ng/mg of tissue, p<0.87). However, HF-fed MSEW showed increased eWAT mRNA expression of tryptophan hydroxylase 1 (Tph1), the rate limiting enzyme in serotonin (5-HT) synthesis (10.2±2.9 vs. 1.6±0.3 2 -ΔΔct , p<0.03). SERT-Tph1-MAO signaling pathway protein expression was activated, and fat serotonin concentration was also increased in eWAT from obese MSEW mice compared to C (16.58±1.5 vs. 8.5±2.1 ug/mg of tissue, p<0.01). Acute stimulation of eWAT with serotonin (10-6 M, 4 sites, 2 ul/site) tend to increase pressor response in MSEW mice (p<0.066, n=2-3). Unlike in female MSEW mice, our study demonstrates that MSEW does not increase circulating and tissue AGT, Ang II and leptin in male mice. Taken together, these data suggest that increased local serotonin could be endogenously sensitizing the sensory neurons in obese MSEW mice contributing to chronic AAR stimulation, directly via TRPV1 channels, or indirectly, via acid-sensing ion channels.


2013 ◽  
Vol 144 (5) ◽  
pp. S-57 ◽  
Author(s):  
Kazunari Tominaga ◽  
Yoshiko Fujikawa ◽  
Fumio Tanaka ◽  
Mitsue Sogawa ◽  
Hirokazu Yamagami ◽  
...  

2010 ◽  
Vol 299 (1) ◽  
pp. R185-R191 ◽  
Author(s):  
Analia S. Loria ◽  
Gerard D'Angelo ◽  
David M. Pollock ◽  
Jennifer S. Pollock

We hypothesized that early life stress enhances endothelin (ET-1)-dependent acute stress responses in adulthood. We utilized a unique rat model, wild-type (WT) and ETB receptor-deficient spotting lethal ( sl/sl) rats, as well as pharmacological blockade of ET receptors, in a model of early life stress, maternal separation (MS). MS was performed in male WT and sl/sl rats 3 h/day from day 2 to 14 of life. Acute air jet stress (AJS)-induced responses (elevation in blood pressure, plasma corticosterone, and plasma ET-1) were evaluated in adult MS rats compared with the nonhandled littermate (control) rats. MS significantly augmented the acute AJS-induced blood pressure response (area under the curve) in WT rats compared with control, while the AJS-induced pressor responses were similar in sl/sl MS and control rats. ET receptor blockade significantly blunted the AJS-induced pressor response in WT MS and control rats. Moreover, AJS-induced plasma corticosterone levels in control rats were sensitive to ET receptor blockade, yet, AJS did not alter plasma corticosterone levels in MS rats. MS significantly increased circulating ET-1 levels, and AJS-induced plasma ET-1 levels were similarly increased in control and MS rats. MS induced a significant downregulation in expression of ETA and ETB receptors in aortic tissue compared with control rats. These results indicate that early life stress reduced expression of ETA and ETB receptors, leading to alterations in the ET pathway, and an exaggerated acute stress-mediated pressor response in adulthood.


2021 ◽  
Vol 22 (4) ◽  
pp. 1899 ◽  
Author(s):  
Hae Jeong Park ◽  
Sang A. Kim ◽  
Won Sub Kang ◽  
Jong Woo Kim

Recent studies have reported that changes in gut microbiota composition could induce neuropsychiatric problems. In this study, we investigated alterations in gut microbiota induced by early-life stress (ELS) in rats subjected to maternal separation (MS; 6 h a day, postnatal days (PNDs) 1–21), along with changes in inflammatory cytokines and tryptophan-kynurenine (TRP-KYN) metabolism, and assessed the differences between sexes. High-throughput sequencing of the bacterial 16S rRNA gene showed that the relative abundance of the Bacteroides genus was increased and that of the Lachnospiraceae family was decreased in the feces of MS rats of both sexes (PND 56). By comparison, MS increased the relative abundance of the Streptococcus genus and decreased that of the Staphylococcus genus only in males, whereas the abundance of the Sporobacter genus was enhanced and that of the Mucispirillum genus was reduced by MS only in females. In addition, the levels of proinflammatory cytokines were increased in the colons (IFN-γ and IL-6) and sera (IL-1β) of the male MS rats, together with the elevation of the KYN/TRP ratio in the sera, but not in females. In the hippocampus, MS elevated the level of IL-1β and the KYN/TRP ratio in both male and female rats. These results indicate that MS induces peripheral and central inflammation and TRP-KYN metabolism in a sex-dependent manner, together with sex-specific changes in gut microbes.


2018 ◽  
Vol 246 (3) ◽  
pp. 155-165 ◽  
Author(s):  
Ryusuke Ouchi ◽  
Tasuku Kawano ◽  
Hitomi Yoshida ◽  
Masato Ishii ◽  
Tomomitsu Miyasaka ◽  
...  

2019 ◽  
Vol 79 (1) ◽  
pp. 113-132 ◽  
Author(s):  
Marion Rincel ◽  
Muriel Darnaudéry

The developmental period constitutes a critical window of sensitivity to stress. Indeed, early-life adversity increases the risk to develop psychiatric diseases, but also gastrointestinal disorders such as the irritable bowel syndrome at adulthood. In the past decade, there has been huge interest in the gut–brain axis, especially as regards stress-related emotional behaviours. Animal models of early-life adversity, in particular, maternal separation (MS) in rodents, demonstrate lasting deleterious effects on both the gut and the brain. Here, we review the effects of MS on both systems with a focus on stress-related behaviours. In addition, we discuss more recent findings showing the impact of gut-directed interventions, including nutrition with pre- and probiotics, illustrating the role played by gut microbiota in mediating the long-term effects of MS. Overall, preclinical studies suggest that nutritional approaches with pro- and prebiotics may constitute safe and efficient strategies to attenuate the effects of early-life stress on the gut–brain axis. Further research is required to understand the complex mechanisms underlying gut–brain interaction dysfunctions after early-life stress as well as to determine the beneficial impact of gut-directed strategies in a context of early-life adversity in human subjects.


Sign in / Sign up

Export Citation Format

Share Document