Development of serotonin-induced ion currents in identified embryonic Retzius cells from the medicinal leech (Hirudo medicinalis).
Research article published in The Journal of neuroscience : the official journal of the Society for Neuroscience (1991)
Abstract
Retzius cells and the cutaneous baroreceptive P-cells of adult medicinal leeches (Hirudo medicinalis) respond to 5-HT by Cl- as well as by monovalent cation conductances (Drapeau et al., 1989). However, chemical synaptic connections between Retzius cells (Liu and Nicholls, 1989) as well as Retzius cells and P-cells in culture (Drapeau and Sanchez-Armass, 1988) are mediated by postsynaptic Cl- currents in response to 5-HT release from the presynaptic cell. It was the aim of the present study to find out whether the response, which has been shown to be involved in synaptic transmission or whether the cation current, which has so far only been observed upon extrasynaptic 5-HT application, dominates during embryogenesis. Currents induced by transmitter application with a fast perfusion system were measured with a single-electrode voltage clamp and patch pipettes in whole-cell configuration. Control experiments, performed on Retzius cells from adult leeches after 1 d in culture, showed Cl- currents in response to 5-HT application in all cells investigated. Ninety percent of the cells tested showed additional 5-HT-elicited Na+, K+, or both currents. However, the conductance of cation currents amounted only to 10% of the Cl- currents. Embryonic Retzius cells were identified in dissociated cultures by their violet-blue fluorescence acquired by preincubation of intact ganglia or embryos in culture medium containing the autofluorescent 5-HT analog 5,7-dihydroxytryptamine. The first responses to 5-HT were measured at embryonic day 10 (E10), after voltage-activated Ca2+ and Na+ currents had already developed. 5-HT application induced exclusively Cl- currents until E16. This suggests that the receptor-channel complex, which also mediates synaptic responses, is expressed first in measurable quantities. Hence, there is currently no indication that extrasynaptic receptors dominate in immature cells in this preparation.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Retzius cells and the cutaneous baroreceptive P-cells of adult medicinal leeches (Hirudo medicinalis) respond to 5-HT by Cl- as well as by monovalent cation conductances (Drapeau et al., 1989). However, chemical synaptic connections between Retzius cells (Liu and Nicholls, 1989) as well as Retzius...
Por qué esto importa para la hirudoterapia
Este estudio electrofisiológico examinó la aparición durante el desarrollo de corrientes iónicas inducidas por serotonina (5-HT) en neuronas de Retzius embrionarias identificadas de la sanguijuela medicinal (Hirudo medicinalis), utilizando fijación de voltaje con electrodo único y pipetas de parche en configuración de célula completa. Las corrientes de Cl-, que median las respuestas sinápticas, se desarrollaron primero en el día embrionario 10, mientras que las conductancias catiónicas aparecieron más tarde, lo que indica que el complejo receptor-canal sináptico se expresa antes que los receptores extrasinápticos durante la embriogénesis. Este estudio trata sobre la neurobiología de una especie de sanguijuela. Advertencia: Se trata de un estudio básico de neurociencia sobre el desarrollo neuronal embrionario; el resumen no contiene ninguna mención a la hirudoterapia o al secretoma de la sanguijuela, y su relevancia para el ámbito de ASH se limita a la biología fundamental de la sanguijuela.
Citación
Development of serotonin-induced ion currents in identified embryonic Retzius cells from the medicinal leech (Hirudo medicinalis).
Lessmann et al. · The Journal of neuroscience : the official journal of the Society for Neuroscience, 1991
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: 18 de junio de 2026