Cholinergic partition cells and lamina x neurons induce a muscarinic-dependent short-term potentiation of commissural glutamatergic inputs in lumbar motoneurons.
Front. Neural Circuits. 2011-01-01; 5:
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1. Front Neural Circuits. 2011 Nov 4;5:15. doi: 10.3389/fncir.2011.00015.
Cholinergic partition cells and lamina x neurons induce a muscarinic-dependent
short-term potentiation of commissural glutamatergic inputs in lumbar
Bertrand SS(1), Cazalets JR.
(1)CNRS UMR 5287, INCIA, Université de Bordeaux Bordeaux, France.
Acetylcholine and the activation of muscarinic receptors influence the activity
of neural networks generating locomotor behavior in the mammalian spinal cord.
Using electrical stimulations of the ventral commissure, we show that commissural
muscarinic (CM) depolarizations could be induced in lumbar motoneurons. We
provide a detailed electrophysiological characterization of the muscarinic
receptors and the membrane conductance involved in these responses. Activation of
the CM terminals, originating from lamina X neurons and partition cells, induced
a pathway-specific short-term potentiation (STP) of commissural glutamatergic
inputs in motoneurons. This STP is occluded in the presence of the muscarinic
antagonist atropine. During fictive locomotion, the activation of the commissural
pathways transiently enhanced the motor output in a muscarinic-dependent manner.
This study describes for the first time a novel regulatory mechanism of synaptic
strength in spinal locomotor networks. Such cellular mechanisms would endow the
locomotor central pattern generators with adaptive processes needed to generate
appropriate synaptic inputs to motoneurons during different motor tasks.