American Society of Hirudotherapy

Axonal projections of the Retzius cells to the dorsal segmental root in the leech Hirudo medicinalis.

Research article published in Archives italiennes de biologie (1987)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsSalivary PharmacologyCarretta et al. · Archives italiennes de biologie, 1987

Abstract

The presence of RC's axon running in the dorsal root of the leech Hirudo medicinalis was studied by means of electrophysiological and neuroanatomical techniques. Electrical stimulation of the dorsal root gave invariably the antidromic invasion of the Retzius cell. This effect disappears after crushing the dorsal root between the stimulating electrode and the ganglion, and hence is not due to stimulus spread to the nearby posterior root. Anatomical evidence for an axon collateral running in the dorsal root was provided by catecholamine histofluorescence of the axonal branches of the RCs and by Lucifer Yellow intracellular injection into the RCs.

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

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAnimalsAxonsCatecholaminesElectric StimulationHistocytochemistryInjectionsIntracellular MembranesIsoquinolinesLeechesMicroscopy, FluorescenceNeuronsSynaptic Transmission

Summary

The presence of RC's axon running in the dorsal root of the leech Hirudo medicinalis was studied by means of electrophysiological and neuroanatomical techniques. Electrical stimulation of the dorsal root gave invariably the antidromic invasion of the Retzius cell.

Why This Matters for Hirudotherapy

This study examined the axonal projections of Retzius cells into the dorsal segmental root of the medicinal leech Hirudo medicinalis using electrophysiological stimulation, catecholamine histofluorescence, and Lucifer Yellow intracellular injection. The authors demonstrated antidromic invasion of the Retzius cell upon electrical stimulation of the dorsal root and provided anatomical evidence for an axon collateral running in the dorsal root via catecholamine histofluorescence and dye injection. For ASH, this work is indirectly relevant as basic neurobiological research on Hirudo medicinalis, the species used in modern hirudotherapy. CAVEAT: The study is purely neuroanatomical with no connection to salivary biochemistry, anticoagulant properties, or therapeutic applications; its relevance to ASH's clinical domain is limited to fundamental leech biology.

Citation

Axonal projections of the Retzius cells to the dorsal segmental root in the leech Hirudo medicinalis.

Carretta et al. · Archives italiennes de biologie, 1987

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

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