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. 1983 Oct;343:341–359. doi: 10.1113/jphysiol.1983.sp014896

Post-synaptic potentials in a population of motoneurones following activity of single interneurones in the cat.

E Brink, P J Harrison, E Jankowska, D A McCrea, B Skoog
PMCID: PMC1193923  PMID: 6644620

Abstract

The technique of recording post-synaptic potentials from a population of motoneurones, by recording from ventral roots perfused with isotonic sucrose, has been applied to investigate the action of single last-order interneurones; the target motoneurones were in either caudal L7 or S1 segments. Using spike-triggered averaging, the inhibitory action of 70% of previously identified last-order interneurones (Renshaw cells and lamina VII Ia inhibitory interneurones) has been detected. Previous observations had suggested that interneurones mediating disynaptic non-reciprocal inhibition from group I muscle afferents should be characterized by (i) location in laminae V-VI, (ii) monosynaptic group I input and (iii) ascending collateral axonal projection to upper lumbar segments. 65% of interneurones with these characteristics were found to inhibit motoneurones. In addition, spike-triggered averaging from this group of laminae V-VI interneurones sometimes revealed a depolarizing potential which preceded the inhibitory potential evoked by the interneurone. The depolarizing potential is interpreted as being due to the action of some presynaptic fibres which branch to innervate both the investigated interneurones and motoneurones.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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