Sociedad Americana de Hirudoterapia

On the termination of ingestive behaviour by the medicinal leech

Physiology study published in Journal of Experimental Biology (1987)

Última actualización: June 18, 2026Revisado por: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genómica y proteómicaLent CM, Dickinson MH · Journal of Experimental Biology, 1987

Abstract

Hungry leeches, Hirudo medicinalis, ingest blood meals averaging 890% of their mass in 29 min. Ingestion is terminated as a result of distension of the body: experimentally distending leeches as they feed causes an immediate cessation of ingestion and inhibits any subsequent biting behaviour; if distension is circumvented by various experimental procedures, leech ingestive periods are prolonged significantly. Ingestion is not terminated as a result of fatigue, chemical cues or mass change. Distension also underlies satiation, for removing blood from the crops of recently fed leeches qualitatively alters their satiated behaviour to biting. Biting is not a defensive reaction to injury. In rostral ganglia, impulses of the serotonergic Retzius (RZ) and LL neurones evoke the physiological components of ingestion. Localized warming of the prostomial lip induces impulses in these large effector neurones. Distending the body wall tonically hyperpolarizes the RZ and LL cells. This inhibitory response to distension is conducted from the mid-body to the anterior neurones via the ventral nerve cord. Distensive inhibition antagonizes the synaptic excitation evoked in RZ and LL neurones by thermal stimulation. Thus, a stimulus which evokes feeding synaptically excites 5-HT neurones and a stimulus which terminates ingestion inhibits them. The integration of these inputs controls the expression of leech feeding behaviour and these connections match precisely a model proposed to regulate the ingestive behaviour of blowflies.

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 termsAnimalsDigestive SystemDigestive System Physiological PhenomenaEatingFeeding BehaviorLeeches

Resumen

Hungry leeches ingest 890% of body mass in 29 min; ingestion termination is driven by body wall distension, which tonically hyperpolarizes the serotonergic Retzius and LL effector neurons. Distension circumvention experiments prolonged feeding significantly.

Por qué esto importa para la hirudoterapia

This study investigated how blood-feeding is terminated in Hirudo medicinalis, reporting that body-wall distension—not fatigue, chemical cues, or mass change—ends ingestion and inhibits subsequent biting, while preventing distension prolongs feeding. Distension tonically hyperpolarizes serotonergic Retzius and LL neurons in the rostral ganglia via the ventral nerve cord, antagonizing the excitation produced by localized warming of the prostomial lip. The neural control pattern matches a model previously proposed for blowfly ingestive behaviour, but the abstract provides no information on salivary components, secretome actions, or therapeutic application. Caveat: this is basic neuroscience in an invertebrate model with no clinical data; its relevance to hirudotherapy is indirect and limited to the biological control of leech feeding.

Citación

On the termination of ingestive behaviour by the medicinal leech.

Lent CM, Dickinson MH · Journal of Experimental Biology, 1987

Contexto clínico relacionado

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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: June 18, 2026

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