Dorsal Spinal Interneurons Forming a Primitive, Cutaneous Sensory Pathway

Wenchang Li, S.R. Soffe, A. Roberts

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

In mammals, sensory projection pathways are provided by just three classes of spinal interneuron that develop from the roof-plate. We asked whether similar sensory projection interneurons are present primitively in a developing lower vertebrate where function can be more readily studied. Using an immobilized Xenopus tadpole spinal cord preparation, we define the properties and connections of spinal sensory projection interneurons using whole cell patch recordings from single neurons or pairs, identified by dye filling. Dorsolateral interneurons lie in the tadpole equivalent of the spinal dorsal horn, and have dorsally located dendrites and an ipsilateral ascending axon that projects into the midbrain. These neurons receive direct, mainly AMPA receptor (AMPAR)-mediated, excitation from skin touch sensory neurons. They in turn produce AMPAR and N-methyl-D-aspartate receptor (NMDAR)-mediated excitation of spinal locomotor pattern generator neurons rostrally on the same side of the cord. During swimming, they receive glycinergic modulatory inhibition from ascending interneurons in the spinal locomotor central pattern generator. We conclude that spinal dorsolateral interneurons are a primitive class of excitatory sensory projection neurons activated by ipsilateral cutaneous afferents and carrying excitation ipsilaterally and rostrally as far as the midbrain to initiate or accelerate swimming.
Original languageEnglish
Pages (from-to)895-904
Number of pages10
JournalJournal of Neurophysiology
Volume92
Issue number2
DOIs
Publication statusPublished - Aug 2004

Keywords

  • XENOPUS-LAEVIS EMBRYOS
  • PHASE-DEPENDENT MODULATION
  • NEURONAL DIFFERENTIATION
  • SIMPLE VERTEBRATE
  • RHYTHM GENERATOR
  • CORD
  • RESPONSES
  • SPECIFICATION
  • STIMULATION
  • PROJECTIONS

Fingerprint

Dive into the research topics of 'Dorsal Spinal Interneurons Forming a Primitive, Cutaneous Sensory Pathway'. Together they form a unique fingerprint.

Cite this