Muscarinic control of AMPA receptor responsiveness in mouse spinal cord motoneurons.
A cholinergic synaptic input has been highlighted in recent years as an important modulator of motoneuron excitability. In the present study, it was examined whether, as in other regions, the cholinergic inputs on spinal motoneurons modulate the glutamatergic synaptic activity, evoked by electrical stimulation at the dorsolateral funiculus. The present results show that the pharmacological stimulation of muscarinic receptors produces a selective depression of AMPA-mediated glutamatergic activity in thoracic and lumbar spinal motoneurons. This effect does not involve a change in transmitter release and occurs both on synaptic currents and on AMPA responses evoked by photolysis of MNI-glutamate. Thus, it is concluded that muscarinic modulation occurs at the postsynaptic level. The results suggest that cholinergic inputs contacting motoneurons, which are known to increase motoneuron excitability, also directly interfere within coming synaptic inputs by changing their amplitudes.
Laboratoire de Physiologie Cérébrale, CNRS UMR 8118, 45 rue des Saints Pères, 75006 Paris, France. sheylavianey@gmail.com
Sheyla
S
Mejia-Gervacio
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials; D005971:Glutamates / Q000494:pharmacology; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D018721:Muscarinic Agonists / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D018091:Receptors, AMPA / Q000502:physiology*; D011976:Receptors, Muscarinic / Q000502:physiology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
C440256:4-methoxy-7-nitroindolinyl-glutamate; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D007211:Indoles; D018721:Muscarinic Agonists; D011810:Quinoxalines; D018091:Receptors, AMPA; D011976:Receptors, Muscarinic; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid