title: Spinal neurons bursting in phase with fictive scratching are not related to spontaneous cord dorsum potentials.
abstract: Spontaneous cord dorsum potentials (spontaneous CDPs) are produced by the activation of dorsal horn neurons distributed along the L4 to S1 spinal cord segments, in Rexed's laminae III-VI, in the same region in which there are interneurons rhythmically bursting during fictive scratching in cats. An interesting observation is that spontaneous CDPs are not rhythmically superimposed on the sinusoidal CDPs generated during fictive scratching episodes, thus suggesting that the interneurons producing both types of CDPs belong to different spinal circuits. In order to provide experimental data to support this hypothesis, we recorded unitary activity of neurons in the L6 spinal cord segment. We found that the neurons firing rhythmically during the sinusoidal CDPs associated with the extensor, flexor or intermediate phases of scratching were not synchronized with the spontaneous CDPs. Moreover, we found that the neurons firing during the spontaneous CDPs were not synchronized with the sinusoidal CDPs. These results suggest that the neurons involved in the occurrence of spontaneous CDPs are not part of the spinal cord central pattern generators (CPGs). This study will be relevant for understanding the relationships between the spinal cord neuronal populations firing spontaneously and the CPGs, in the intact and injured spinal cord.
authors: Departamento de Fisiología, Biofísica y Neurociencias CINVESTAV, Mexico.
authors: C A
authors: CA
authors: Cuellar
authors: Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, Colonia San Manuel, Apartado Postal 406, CP 72570 Puebla, Pue., Mexico.
authors: A
authors: A
authors: Trejo
authors: Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, Colonia San Manuel, Apartado Postal 406, CP 72570 Puebla, Pue., Mexico.
authors: P
authors: P
authors: Linares
authors: Departamento de Fisiología, Biofísica y Neurociencias CINVESTAV, Mexico.
authors: R
authors: R
authors: Delgado-Lezama
authors: Departamento de Fisiología, Biofísica y Neurociencias CINVESTAV, Mexico.
authors: I
authors: I
authors: Jiménez-Estrada
authors: Institute of Basic Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya Street 18, 420008 Kazan, Russia.
authors: L M
authors: LM
authors: Abyazova
authors: Institute of Basic Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya Street 18, 420008 Kazan, Russia.
authors: T V
authors: TV
authors: Baltina
authors: Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, Colonia San Manuel, Apartado Postal 406, CP 72570 Puebla, Pue., Mexico. Electronic address: eliasmanjarrez@gmail.com.
authors: E
authors: E
authors: Manjarrez
mesh_terms: D000818:Animals; D002415:Cats; D063226:Central Pattern Generators / Q000502:physiology*; D004594:Electrophysiology; D009043:Motor Activity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*
keywords: CDP; CPG; central pattern generator; dorsal horn neurons; scratching; spontaneous