Group III mGluR-mediated depression of sensory synaptic transmission.
The effect of L-AP4, a group III mGluR agonist, on sensory synaptic transmission in the lamprey spinal cord has been analyzed. Paired recordings were made between cutaneous mechanosensory neurons (dorsal cells) and postsynaptic spinobulbar giant interneurons. L-AP4 reduced the monosynaptic dorsal cell-evoked EPSP, but at concentrations higher (200-500 microM) than those necessary to depress reticulospinal axon-evoked EPSPs. Stimulation of the dorsal column, which contains dorsal cell axons and the axons of putative nociceptive and theromosensory axons, elicited compound EPSPs that were consistently depressed by L-AP4. Sensory inputs in the lamprey are thus inhibited by group III mGluRs.
Krieger
Patrik
P
Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden. patrik.krieger@neuro.ki.se
El Manira
Abdeljabbar
A
D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology*; D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D007798:Lampreys; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D020671:Posterior Horn Cells / Q000187:drug effects / Q000502:physiology; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D000613:Aminobutyrates; D018690:Excitatory Amino Acid Agonists; D009419:Nerve Tissue Proteins; D018094:Receptors, Metabotropic Glutamate; C102718:metabotropic glutamate receptor 3; C012729:2-amino-4-phosphonobutyric acid