On the termination of ingestive behaviour by the medicinal leech
Physiology study published in 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.
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
Este estudio investigó cómo se pone fin a la hematofagia en Hirudo medicinalis, informando de que la distensión de la pared corporal —y no la fatiga, las señales químicas ni el cambio de masa— pone fin a la ingestión e inhibe las mordeduras posteriores, mientras que prevenir la distensión prolonga la alimentación. La distensión hiperpolariza tónicamente las neuronas serotonérgicas de Retzius y LL en los ganglios rostrales a través del cordón nervioso ventral, antagonizando la excitación producida por el calentamiento localizado del labio prostomial. El patrón de control neural coincide con un modelo propuesto previamente para el comportamiento ingestivo de la mosca azul, pero el resumen no aporta información sobre componentes salivales, acciones del secretoma ni aplicación terapéutica. Advertencia: se trata de neurociencia básica en un modelo invertebrado sin datos clínicos; su relevancia para la hirudoterapia es indirecta y se limita al control biológico de la alimentación de la sanguijuela.
Citación
On the termination of ingestive behaviour by the medicinal leech.
Lent CM, Dickinson MH · Journal of Experimental Biology, 1987
Contexto clínico relacionado
Explore cómo esta investigación se conecta con la práctica clínica
Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026