Corticospinal transmission to motoneurons in cervical spinal cord slices from adult rats

Life Sci. 2002 Dec 20;72(4-5):389-96. doi: 10.1016/s0024-3205(02)02279-8.


Cervical spinal cord slices were prepared from adult rats. Intracellular recordings from motoneurons revealed that electrical stimulation of the ventralmost part of the dorsal funiculus (which contains primarily descending corticospinal axons) elicited EPSPs in 75% of the neurons. The latencies of these EPSPs tended to be shorter than those elicited by dorsal horn gray matter stimulation. Pairs of subthreshold dorsal funiculus stimuli were able to elicit action potentials in motoneurons. These data are consistent with previous morphological and electrophysiological studies indicating that cervical motoneurons receive both mono-and polysynaptic corticospinal inputs. In addition, motoneurons were markedly depolarized by iontophoretic application of AMPA or KA (7 out of 7 neurons), but only weakly depolarized by NMDA (1 out of 6 neurons). CNQX (but not AP-5) blocked EPSPs elicited by dorsal funiculus stimulation. Thus, corticospinal transmission to motoneurons is mediated primarily by non-NMDA glutamate receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Axons / physiology
  • Cerebral Cortex / cytology
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiology*
  • Electrophysiology
  • Excitatory Amino Acid Agonists / pharmacology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Excitatory Postsynaptic Potentials / drug effects
  • Excitatory Postsynaptic Potentials / physiology
  • In Vitro Techniques
  • Iontophoresis
  • Male
  • Motor Neurons / drug effects
  • Motor Neurons / physiology*
  • N-Methylaspartate / pharmacology
  • Pyramidal Tracts / drug effects
  • Pyramidal Tracts / physiology*
  • Rats
  • Rats, Wistar
  • Spinal Cord / cytology
  • Spinal Cord / drug effects
  • Spinal Cord / physiology*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology


  • Excitatory Amino Acid Agonists
  • Excitatory Amino Acid Antagonists
  • N-Methylaspartate
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid