ZFIN ID: ZDB-PUB-070303-45
A topographic map of recruitment in spinal cord
McLean, D.L., Fan, J., Higashijima, S., Hale, M.E., and Fetcho, J.R.
Date: 2007
Source: Nature   446(7131): 71-75 (Journal)
Registered Authors: Fetcho, Joseph R., Hale, Melina, Higashijima, Shin-ichi
Keywords: none
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Electrophysiology
  • Glycine Plasma Membrane Transport Proteins/genetics
  • Interneurons/physiology
  • Larva/cytology
  • Larva/physiology
  • Motor Neurons/physiology
  • Spinal Cord/anatomy & histology
  • Spinal Cord/cytology*
  • Spinal Cord/physiology*
  • Swimming/physiology
  • Zebrafish/anatomy & histology
  • Zebrafish/physiology*
PubMed: 17330042 Full text @ Nature
ABSTRACT
Animals move over a range of speeds by using rhythmic networks of neurons located in the spinal cord. Here we use electrophysiology and in vivo imaging in larval zebrafish (Danio rerio) to reveal a systematic relationship between the location of a spinal neuron and the minimal swimming frequency at which the neuron is active. Ventral motor neurons and excitatory interneurons are rhythmically active at the lowest swimming frequencies, with increasingly more dorsal excitatory neurons engaged as swimming frequency rises. Inhibitory interneurons follow the opposite pattern. These inverted patterns of recruitment are independent of cell soma size among interneurons, but may be partly explained by concomitant dorso-ventral gradients in input resistance. Laser ablations of ventral, but not dorsal, excitatory interneurons perturb slow movements, supporting a behavioural role for the topography. Our results reveal an unexpected pattern of organization within zebrafish spinal cord that underlies the production of movements of varying speeds.
ADDITIONAL INFORMATION