An increase in activity of serotonergic Retzius neurones may not be necessary for the consummatory phase of feeding in the leech Hirudo medicinalis.

During the consummatory phase of feeding, in which blood is ingested, medicinal leeches display a characteristic set of behaviours: they extend their jaws, are less responsive to sensory input, produce mucus, relax the body wall and exhibit waves of peristalsis that can run the length of the body. Earlier reports suggested that this pattern of behaviour is orchestrated by serotonin released from Retzius cells in response to the appropriate sensory stimulation of the lip. We have developed a semi-intact preparation in which only the nervous system in the posterior half of the leech was exposed. The front half of the leech was free to explore, bite through and feed until satiated from a blood-filled sausage casing while continuous intracellular and extracellular recordings were made from identified cells and the nerve roots of the exposed segments. Prior to attachment of the animal to the feeding device, the firing frequency of the Retzius cell increased transiently during spontaneous movements or tactile stimuli to its front or posterior end. In contrast, Retzius cell activity decreased after the anterior sucker attached to the membrane of the feeding device at about the time when ingestion was initiated. Increased activity of Leydig cells, which are known to modulate several circuits in the leech, was also associated with exploration. However, unlike that of Retzius cells, the activity of Leydig cells increased significantly following the onset of consumption. These results suggest that increased activity of Retzius cells in midbody ganglia is not a prerequisite for the consummatory phase of feeding and raises questions regarding the role of serotonin in regulating this behaviour.

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

During the consummatory phase of feeding, in which blood is ingested, medicinal leeches display a characteristic set of behaviours: they extend their jaws, are less responsive to sensory input, produce mucus, relax the body wall and exhibit waves of peristalsis that can run the length of the body....

Explore cómo esta investigación se conecta con la práctica clínica

More peer-reviewed studies in Genómica y proteómica.

• 434 Salivary Proteins — Integrated Proteomics of Hirudo medicinalis — Liu et al. (2019)
• Medicinal Leech Genome Assembly — Anticoagulant Gene Catalog — Kvist et al. (2020)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• HIRUDOTHERAPY IN PRESBYACUZIS PRAECOX IN CLEAN-UP WORKERS AFTER THE CHORNOBYL ACCIDENT DURING THE POST-CATASTROPHE YEARS — Zabolotnyi D, Mishchanchuk N (2019)
• AIF-1 and RNASET2 Play Complementary Roles in the Innate Immune Response of Medicinal Leech — Baranzini N et al. (2019)
• Study on the effect of medicinal leech therapy (Hirudo medicinalis) on full-thickness excisional wound healing in the animal model — Zakian A et al. (2022)
• The duration of rest and feeding greatly affects the re-breeding of ectoparasites: Hirudo verbana, Hirudo medicinalis and Hirudo orientalis — Aminov R, Frolov A, Aminova A (2022)
• [Research progress in hirudin fusion protein--review] — Zhang C et al. (2007)
• In-vitro antileishmanial potential of peptide drug hirudin — Khan H et al. (2017)
• Bacterial symbioses of the medicinal leech Hirudo verbana — Nelson M, Graf J (2012)

Browse all ASH-analysed research →