Modulation of nociceptive-like behavior in zebrafsh (Danio rerio) by environmental stressors

Zebrafsh have been demonstrated to react consistently to noxious chemical stimuli and present reliable phenotypes of stress, fear, and anxiety. In this article, we describe the modulation of nociceptive-like responses of zebrafsh to fear-, stress-, and anxiety-eliciting situations. Animals were exposed to an alarm substance, confnement stress, or a novel environment before being injected with 1% acetic acid in the tail. The alarm substance and confnement stress reduced the display of erratic movements and tail-beating behavior elicited by acetic acid. The novelty of the environment, in contrast, increased the frequency of tail-beating behavior. The results suggest that descending modulatory control of nociception exists in zebrafsh, with apparent fear- and stress-induced analgesia and anxiety-induced hyperalgesia.