Identification of Serotonin Within Vital‐stained Neurons From Leech Ganglia

Abstract

Abstract— We have measured serotonin (5‐HT) within large and small neurosomata which are vitally stained by Neutral Red dye. A micro‐radioenzymatic technique which is sensitive to 50fmol of 5‐HT was employed on intact ganglia, 75 μm Retzius Cells (RZ) and a 10 μm ventro‐lateral cell (VL) taken from the leech Macrobdella decora. The stain does not affect the levels of 5‐HT in either ganglia or RZ. The VL cell body contains 5‐HT at concentrations of at least 100 mm. Microspectrofluorometry of all the ganglionic neurosomata which fluoresce following the Falck‐Hillarp formaldehyde condensation reaction detected rapidly‐fading emission peaks of 509–523 nanometers. We conclude that all seven fluorescent neurons in the leech ganglion very probably contain serotonin.

Quantitative effects of a neurotoxin upon serotonin levels within tissue compartments of the medicinal leech

“…The serotonin content of the pharynx and ganglia of these toxin-treated leeches were lowered significantly. The serotonin levels within the body wall and salivary glands were not altered significantly by the toxin treatment, but the levels within the vasofibrous tissue and blood were elevated substantially.( Lent et al, 1979). Certain of these interneurons activate the central pattern generator responsible for producing swimming behavior (Nusbaum and Kristan, 1982).…”

“…( Lent et al, 1979). Certain of these interneurons activate the central pattern generator responsible for producing swimming behavior (Nusbaum and Kristan, 1982).…”

Leydig neuron activity modulates heartbeat in the medicinal leech

“…The cardioacceleratory Retzius cells are known to contain and release serotonin in the CNS (Lent et al 1979;Willard 198 I). The effects on heart rate of stimulating Retzius cells are mimicked by bath applications of serotonin to nerve cords (Arbas unpubl, obs.…”

Aminergic neurons in the anterior nervous system of the rat acanthocephalan moniliformis dubius

“…Invertebrate neurons that contain biogenic amines such as dopamine, octopamine, and serotonin may be stained with the vital dye neutral red (Stuart, Hudspeth, and Hall, 1974;Evans et al, 1976;O'Shea, 1977,1978;Lent, et al, 1979;Evans, 197833). However, some amine-containing cells may not demonstrate an affinity for neutral red dye (Webb and Orchard, 1980).…”