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Updated: Aug 10, 2026
09:48
Measuring Spinal Presynaptic Inhibition in Mice By Dorsal Root Potential Recording In Vivo
Published on: March 29, 2014
Presynaptic kainate receptors regulate spinal sensory transmission
G A Kerchner1, T J Wilding, P Li
1Washington University Pain Center, Department of Anesthesiology, St. Louis, Missouri 63110, USA.
Summary
Kainate receptors on sensory neurons can reduce glutamate release in the spinal cord. This study shows kainate agonists suppress excitatory transmission from dorsal root ganglion cells to spinal dorsal horn neurons.
Area of Science:
- Neuroscience
- Neuropharmacology
- Synaptic Transmission
Background:
- Small diameter dorsal root ganglion (DRG) neurons transmit pain signals and express functional kainate receptors.
- Kainate receptor activation depolarizes C-fiber afferents, but their role on sensory afferents remains unclear.
- Presynaptic kainate receptors are hypothesized to modulate glutamate release in the spinal cord.
Purpose of the Study:
- To investigate the role of kainate receptors in regulating glutamate release from sensory afferents.
- To determine the effects of kainate and specific agonists on synaptic transmission in the spinal cord.
- To characterize kainate receptor subtypes expressed by DRG and dorsal horn neurons.
Main Methods:
- Electrophysiological recordings in cultured spinal dorsal horn neurons and DRG-dorsal horn neuron cocultures.
- Application of kainate and the selective kainate receptor agonist ATPA.
- Recordings in spinal slices to assess effects on NMDA and AMPA receptor-mediated EPSCs.
Main Results:
- Kainate suppressed spontaneous NMDA receptor-mediated EPSCs in dorsal horn neurons.
- Kainate reduced evoked EPSCs in DRG-dorsal horn neuron cocultures.
- DRG neuron kainate receptors were sensitive to both kainate and ATPA, while dorsal horn neurons primarily responded to kainate.
- Kainate and ATPA suppressed NMDA and AMPA receptor-mediated EPSCs evoked by dorsal root stimulation in spinal slices.
Conclusions:
- Kainate receptor agonists can act presynaptically to reduce glutamate release from primary afferent sensory synapses.
- This suggests a modulatory role for kainate receptors in pain signaling pathways.
- Differential expression and sensitivity of kainate receptors in DRG and dorsal horn neurons are highlighted.
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