American Society of Hirudotherapy

Competitive interactions between neurons making axosomatic contacts in the leech

Research article published in The Journal of neuroscience : the official journal of the Society for Neuroscience (1990)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Clinical TrialsGu et al. · The Journal of neuroscience : the official journal of the Society for Neuroscience, 1990

Abstract

Axons of lateral nociceptive (N) neurons in leech segmental ganglia wrap certain somata in adjacent ganglia but no somata in their own ganglion. In adults, the N neurons, which accurately regenerate axosomatic wrappings, can be induced to sprout in their own ganglion and wrap target homologues if the ganglion is isolated by cutting the nerve cord. Manipulations that denervate the new targets without injuring the lateral N cell, including focal lesions and protease injections into other N cells, also cause sprouting within 2-4 months. In contrast, cutting the lateral N cell's axons causes little or no sprouting within the ganglion without denervation. Therefore, denervation rather than injury accounts for sprouting within the ganglion. It is concluded that lateral N cells can wrap somata in their own ganglion that are homologues of their usual targets, but they are prevented from doing so by axonal wrappings from N cells in adjacent ganglia.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, U.S. Gov't, P.H.S.
Indexed MeSH termsAnimalsAxonsDenervationGangliaLeechesModels, NeurologicalNerve RegenerationNociceptors

Summary

Peer-reviewed clinical and outcomes research relevant to medicinal leech therapy and its biology. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

Using the leech (its segmental ganglia), this study showed that lateral nociceptive (N) neurons can be induced to sprout and wrap homologous cell bodies in their own ganglion after denervation, concluding that denervation rather than axonal injury drives the sprouting and that the cells are normally restrained by wrappings from N cells in adjacent ganglia. Its ASH relevance is as a reminder that the medicinal leech is a foundational model organism in neuroscience, underscoring the species' long scientific pedigree beyond its therapeutic secretome. This is invertebrate neurobiology with no clinical or anticoagulant content, so it bears on the leech as a research animal, not on hirudotherapy outcomes in patients.

Citation

Competitive interactions between neurons making axosomatic contacts in the leech.

Gu et al. · The Journal of neuroscience : the official journal of the Society for Neuroscience, 1990

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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