Primitive Role for GABAergic Reticulospinal Neurones in the Control of Locomotion
All animals need to be able to stop locomotion as well as start it. In hatchling embryos of the clawed toad Xenopus, swimming locomotion can be stopped by pressure on the head or cement gland. The receptors for this response are trigeminal neurones with free nerve endings which project centrally into the brainstem. Our evidence suggests that these receptors excite GABAergic reticulospinal neurones which project to both sides of the spinal cord to inhibit spinal motoneurones and interneurones and in this way turn off the spinal locomotor pattern generator to terminate swimming locomotion. Similar reticulospinal GABAergic pathways have been shown anatomically in mammals.
KeywordsTrigeminal Ganglion Spinal Motoneurones Kynurenic Acid Xenopus Embryo Free Nerve Ending
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