PUBLICATION

Morphological and physiological properties of Rohon-Beard neurons along the zebrafish spinal cord

Authors
Katz, H.R., Menelaou, E., Hale, M.E.
ID
ZDB-PUB-201002-73
Date
2020
Source
The Journal of comparative neurology   529(7): 1499-1515 (Journal)
Registered Authors
Hale, Melina
Keywords
Danio rerio, RRID: SCR_000325, RRID: SCR_001905, RRID: SCR_002285, RRID: SCR_010279, RRID: SCR_016137, feedback, sensory, mechanosensory, peripheral nervous system, sensorimotor, swimming
MeSH Terms
  • Animals
  • Electrophysiology
  • Image Processing, Computer-Assisted
  • Mechanoreceptors/cytology*
  • Mechanoreceptors/physiology*
  • Spinal Cord/cytology*
  • Spinal Cord/physiology*
  • Zebrafish/anatomy & histology*
  • Zebrafish/physiology*
PubMed
32935362 Full text @ J. Comp. Neurol.
Abstract
Primary mechanosensory neurons play an important role in converting mechanical forces into the sense of touch. In zebrafish, Rohon-Beard (RB) neurons serve this role at embryonic and larval stages of development. Here we examine the morphology and physiology of RBs in larval zebrafish to better understand how mechanosensory stimuli are represented along the spinal cord. We report that the morphology of RB neurons differs along the rostrocaudal body axis. Rostral RB neurons arborize in the skin near the cell body whereas caudal cells arborize at a distance posterior to their cell body. Using a novel electrophysiological approach, we also found longitudinal differences in the mechanosensitivity and physiological properties of RB neurons. Rostral RB neurons respond to mechanical stimulations close to the soma and produce up to three spikes with increasing stimulus intensity, whereas caudal cells respond at more distal locations and can produce four or more spikes when the intensity of the mechanical stimulus increases. The mechanosensory properties of RB neurons are consistent with those of rapidly adapting mechanoreceptors and can signal the onset, offset and intensity of mechanical stimulation. This is the first report of the intensity encoding properties of RB neurons, where an increase in spike number and a decrease in spike latency are observed with increasing stimulation intensity. This study reveals an unappreciated complexity of the larval zebrafish mechanosensory system and demonstrates how differences in the morphological and physiological properties of RBs related to their rostrocaudal location can influence the signals that enter the spinal cord.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping