Chemical and electrical stimulation induce rhythmic motor activity in an in vitro preparation of the spinal cord from adult turtles.
Bath application of N-Methyl-D-aspartate (NMDA) and serotonin induced rhythmic activity in hindlimb motoneurons in an isolated spinal cord preparation from adult turtles. Subthreshold concentrations of NMDA and serotonin accompanied by stimulation of the dorsal funiculus also induced rhythmic activity. The induced activity in motoneurons and ventral roots displayed characteristics which resemble that of locomotion. This activity could be evoked in as few as three segments (D8-D10) of the lumbar enlargement isolated from the rest of the spinal cord. The existence of intrinsic oscillations in single neurons was revealed in the presence of tetrodotoxin. Our findings introduce a new in vitro preparation in which electrophysiological and pharmacological tools can be used with ease to study mechanisms of central pattern generation in a mature spinal motor network.
Guertin
P A
PA
Department of Neurophysiology, Panum Institute, University of Copenhagen, Denmark.
Hounsgaard
J
J
D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D066298:In Vitro Techniques; D009068:Movement / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000502:physiology; D013268:Stimulation, Chemical; D014426:Turtles / Q000502:physiology*
D018690:Excitatory Amino Acid Agonists; D012701:Serotonin; D016202:N-Methylaspartate