Ingestive sensory inputs excite serotonin effector neurones and promote serotonin depletion from the leech central nervous system and periphery.
Research article published in The Journal of experimental biology (1995)
Abstract
Thermal and chemical stimuli known to promote ingestive behaviours in the medicinal leech Hirudo medicinalis were tested for their physiological effects on Retzius neurones and for their biochemical effects on serotonin levels in the central nervous system, pharynx and body wall. Retzius neurones throughout the leech nerve cord receive excitatory synaptic input during thermal or chemical stimulation of the prostomial lip. These neurones respond to the rate of change of temperature as well as to absolute temperature at the lip. Exposure of the lip to sodium chloride excites Retzius neurones, whereas exposure to arginine has little effect. Thermal stimulation of the lip elicits a more rapid but less prolonged excitation of Retzius neurones than does chemical stimulation. Stimulation of the prostomial lip is associated with afferent activities in the cephalic nerves D1, D2 and V1-2. Thermal stimulation of the prostomial lip results in depletion of serotonin from midbody ganglia, whereas chemical stimulation has no effect. Conversely, chemical stimulation of the lip results in depletion of serotonin from the body wall, whereas thermal stimulation does not. Pharyngeal serotonin content is decreased with either modality. These data distinguish two important feeding-related sensory input pathways to central serotonergic effector neurones in Hirudo medicinalis.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Thermal and chemical stimuli known to promote ingestive behaviours in the medicinal leech Hirudo medicinalis were tested for their physiological effects on Retzius neurones and for their biochemical effects on serotonin levels in the central nervous system, pharynx and body wall. Retzius neurones...
Por qué esto importa para la hirudoterapia
Este estudio investigó cómo los estímulos térmicos y químicos asociados con el comportamiento de alimentación afectan a las neuronas de Retzius (neuronas efectoras de serotonina) y los niveles de serotonina en el SNC, la faringe y la pared corporal de *Hirudo medicinalis*. Los investigadores encontraron que la estimulación térmica y el cloruro de sodio excitan a las neuronas de Retzius a través de vías distintas, donde la estimulación térmica agota la serotonina de los ganglios del cuerpo medio mientras que la estimulación química la agota de la pared corporal, y ambas agotan la serotonina faríngea. Comprender las vías sensoriales-a-serotonina en la alimentación es relevante para el ámbito de la ASH porque la serotonina es un componente bioactivo clave del secretoma de la sanguijuela y desempeña funciones en la alimentación sanguínea. Sin embargo, se trata de investigación básica en neurofarmacología sin implicaciones clínicas directas para la hirudoterapia.
Citación
Ingestive sensory inputs excite serotonin effector neurones and promote serotonin depletion from the leech central nervous system and periphery.
Groome et al. · The Journal of experimental biology, 1995
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: June 18, 2026