Activation of group I metabotropic glutamate receptors induces long-term depression at sensory synapses in superficial spinal dorsal horn
Low-frequency stimulation of primary afferent Aδ-fibers can induce long-term depression of synaptic transmission in rat superficial spinal dorsal horn. Here, we have identified another form of long-term depression in superficial spinal dorsal horn neurons that is induced by specific group I but not...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
13 December 2000
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| In: |
Neuropharmacology
Year: 2000, Volume: 39, Issue: 12, Pages: 2231-2243 |
| ISSN: | 1873-7064 |
| DOI: | 10.1016/S0028-3908(00)00084-8 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1016/S0028-3908(00)00084-8 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0028390800000848 
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| Author Notes: | J. Chen, B. Heinke, J. Sandkühler |
| Summary: | Low-frequency stimulation of primary afferent Aδ-fibers can induce long-term depression of synaptic transmission in rat superficial spinal dorsal horn. Here, we have identified another form of long-term depression in superficial spinal dorsal horn neurons that is induced by specific group I but not group II metabotropic glutamate receptor (mGluR) agonists. Synaptic strength between Aδ-fibers and dorsal horn neurons was examined by intracellular recordings in a spinal cord-dorsal root slice preparation from young rat. In the presence of bicuculline and strychnine, bath application of (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD) or the specific group I mGluR agonist (S)-3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) but not the specific group II mGluR agonist (2S,2′R,3′R)-2-(2′,3′-dicarboxycyclopropyl)glycine (DCG-IV) for 20 min produced an acute and a long-term depression of synaptic strength. Bath application of the N-methyl-d-aspartate receptor antagonist d-2-amino-5-phosphonovaleric acid did not affect these depressions by (1S,3R)-ACPD. After pre-incubation of slices with pertussis toxin, a G-protein inhibitor, (1S,3R)-ACPD still induced acute and long-term depressions. The phospholipase C inhibitor U73122 stereoselectively blocked the induction of long-term depression without affecting acute synaptic inhibition. This study demonstrates that, in the spinal cord, direct activation of group I mGluRs that are coupled to phospholipase C through pertussis toxin-insensitive G-proteins induces a long-term depression of synaptic strength. This may be relevant to the processing of sensory information in the spinal cord, including nociception. |
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| Item Description: | Gesehen am 03.05.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1873-7064 |
| DOI: | 10.1016/S0028-3908(00)00084-8 |