The role of CRH in behavioral responses to acute restraint stress in zebrafish

Abstract

In teleosts, changes in swimming, exploring, general locomotor activity, and anxious state can be a response to stress mediated by the corticotropin-releasing hormone system activation and its effects on glucocorticoid levels. Zebrafish has been widely used to study neuropharmacology and has become a promising animal model to investigate neurobehavioral mechanisms of stress. In this report the animals were submitted to acute restraint stress for different time lengths (15, 60 and 90 min) for further evaluation of behavioral patterns, whole-body cortisol content, and corticotropin-releasing hormone expression. The results demonstrated an increase in the locomotor activity and an alteration in the swimming pattern during a 5-min trial after the acute restraint stress. Interestingly, all groups of fish tested in the novel tank test exhibited signs of anxiety as evaluated by the time spent in the bottom of the tank. Whole-body cortisol content showed a positive correlation with increased behavioral indices of locomotion in zebrafish whereas molecular analysis of corticotropin-releasing hormone showed a late reduction of mRNA expression (90 min). Altogether, we present a model of acute restraint stress in zebrafish, confirmed by elevated cortisol content, as a valid and reliable model to study the biochemical basis of stress behavior, which seems to be accompanied by a negative feedback of corticotropin-release hormone mRNA expression.

Putative involvement of the nitrergic system on the consolidation, but not initiation, of behavioral sensitization after conspecific alarm substance in zebrafish

“…Acute restraint stress increases erratic swimming in zebrafish (Ghisleni et al 2012), while freezing is increased after chronic unpredictable stress (Chakravarty et al 2013). Erratic swimming is also affected by sustained threat, as predator exposure for 72 h increases this variable in the novel tank test (Stewart et al 2014b).…”

Video-tracking of zebrafish (Danio rerio) as a biological early warning system using two distinct artificial neural networks: Probabilistic neural network (PNN) and self-organizing map (SOM)

“…The second group has lower values, ranging between 85 and 108 • s −1 , and comprising all other categories. According to a study conducted by Ghisleni et al (2012) with adult zebrafish, our results seem to indicate that in the behavior category C and E, fish would be quite stressed. In the previously mentioned study it was found that angular velocity of control animals did not exceed 180 • in magnitude, but all of the stressed animals presented angular velocities above this value.…”

“…This experimental design was chosen in order for each fish to act as a control of itself. Other studies used recording times equal or shorter than those used by us, from 30 min (Nimkerdphol and Nakagawa, 2008) to 5 min (Ghisleni et al, 2012). The same goes for exposure time, from 60 min (Fernandes and Gerlai, 2009) to 10 min (Gebauer et al, 2011).…”

“…2). The trial schedule corresponded to the period of increased activity, between 10 am and 4 pm (Ghisleni et al, 2012;Pather and Gerlai, 2009). The recording time was set at half an hour after the exposure times ( Fig.…”

Unpredictable Chronic Stress Alters Adenosine Metabolism in Zebrafish Brain

“…UCS changes brain physiology and neural circuits [14] and leads to the development of depressive behaviors [15]. In mammalians, the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) have a major role on physiological stress response in the body and constitute the main effector pathways of the stress system, mediating their adaptive functions [3,16] Zebrafish is a helpful model organism to evaluate stress and anxiety [17][18][19][20] and is useful for assessing behavioral and molecular mechanisms of brain disorders [21][22][23], developmental biology, pathophysiology of metabolic diseases, and neurodegeneration [24][25][26][27]. There is a high degree of homology between zebrafish and humans, as the presence of a homologue of the HPA axis, the hypothalamic-pituitary-interrenal axis (HPI).…”