ZFIN ID: ZDB-PUB-180202-1
Terminal Nerve GnRH3 Neurons Mediate Slow Avoidance of Carbon Dioxide in Larval Zebrafish
Koide, T., Yabuki, Y., Yoshihara, Y.
Date: 2018
Source: Cell Reports   22: 1115-1123 (Journal)
Registered Authors: Yoshihara, Yoshihiro
Keywords: GnRH, avoidance behavior, carbon dioxide, chemosensory system, escape behavior, nasal trigeminal pathway, neural activity imaging, terminal nerve, zebrafish
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Avoidance Learning/drug effects
  • Avoidance Learning/physiology*
  • Carbon Dioxide/pharmacology*
  • Gonadotropin-Releasing Hormone/metabolism*
  • Larva
  • Neural Pathways/drug effects
  • Neural Pathways/metabolism
  • Neurons/drug effects*
  • Neurons/metabolism*
  • Pyrrolidonecarboxylic Acid/analogs & derivatives*
  • Pyrrolidonecarboxylic Acid/metabolism
  • Trigeminal Ganglion/drug effects
  • Trigeminal Ganglion/metabolism
  • Zebrafish
PubMed: 29386100 Full text @ Cell Rep.
Escape responses to threatening stimuli are vital for survival in all animal species. Larval zebrafish display fast escape responses when exposed to tactile, acoustic, and visual stimuli. However, their behavioral responses to chemosensory stimuli remain unknown. In this study, we found that carbon dioxide (CO2) induced a slow avoidance response, which was distinct from the touch-evoked fast escape response. We identified the gonadotropin-releasing hormone 3-expressing terminal nerve as the CO2 sensor in the nose. Wide-field calcium imaging revealed downstream CO2-activated ensembles of neurons along three distinct neural pathways, olfactory, trigeminal, and habenulo-interpeduncular, further reaching the reticulospinal neurons in the hindbrain. Ablation of the nose, terminal nerve, or trigeminal ganglion resulted in a dramatic decrease in CO2-evoked avoidance responses. These findings demonstrate that the terminal nerve-trigeminal system plays a pivotal role in triggering a slow chemosensory avoidance behavior in the larval zebrafish.