The amine and amino acid composition in the Retzius cells of the leechHirudo medicinalis

Osborne, Neville N.; Briel, G.; Neuhoff, Volker

doi:10.1007/bf01918644

Cited by 22 publications

(5 citation statements)

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“…This finding is not entirely surprising for the morphology of each ganglion appears to be similar in that each contains, for example, a pair of Retzius cells (2,10,16). Moreover the composition of dansylatable substances in the nervous system was in agreement with the findings of Osborne et al (18), showing that the main substances present are 5-HT, tryptophan, lysine, ornithine, leucine, alanine, glycine, glutamic acid, aspartic acid, phenylalanine, and tyrosine. The fact that there is an apparent even distribution of most of the substances in the nervous system does not mean that none of them have transmitter functions, for it may be that their individual turnover rates have to be measured before such judgment can be given.…”

Section: Discussionsupporting

confidence: 86%

“…All these substances are present in the leech nervous system (13,18,22) though their precise functional significance is not known. Of special interest is 5-HT, since this substance both occurs in abundance within the nervous system (13,23) and is also localized in defined neurons (6, 18,22). It was therefore decided to analyze the possible role of 5-HT further by studying this amine's metabolism and occurrence at different times of the year.…”

Section: Introductionmentioning

confidence: 99%

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Tryptophan metabolism and the occurrence of amino acids and serotonin in the leech (Hirudo medicinalis) nervous system

Stenzel

Neuhoff

1976

J of Neuroscience Research

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The occurrence and distribution of serotonin (5-HT) and amino acids along the central nerve chain of the leech, Hirudo medicinalis, was analyzed using dansyl-chloride in order to obtain information on the functional roles of amines and amino acids. There was no statistical variation in the occurrence of most of the amino acids or serotonin in the different parts of the dorsal nerve chain of the leech. A variation in the serotonin content was found during the year with the highest level occurring in winter. Leech ganglia also accumulated 3H-tryptophan and metabolized part of it to form 5-HTP, 5-HT, and 5-HIAA. The results are discussed from the point of view of 5-HT being a transmitter substance.

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Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Tryptophan metabolism and the occurrence of amino acids and serotonin in the leech (Hirudo medicinalis) nervous system

Stenzel

Neuhoff

1976

J of Neuroscience Research

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“…These levels of serotonin are quantititatively indistinguishable from those which have been measured in these identifiable cells by several chemical methods. These methods include thinlayer chromatography (Rude, Coggeshall, and Vanorden, 1969;Osborne, Briel, and Neuhoff, 1972), fluorometry (McCaman, Weinreich, and McCaman, 1973), gas chromatography-mass spectrometry (McAdoo and Coggeshall, 1976) and micro-radioenzymatic assay (Lent et al, 1979). Ganglionic and blood extracts were mixed with the standard (B) at volumetric ratios 1:2 and 1:1, respectively (tissue:5-HT).…”

Section: S E R O T O N I N ( P M O L )mentioning

confidence: 99%

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

Lent¹

1984

J. Neurobiol.

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The serotonin (5-hydroxytryptamine, 5-HT) content of tissue compartments in the medicinal leech, Hirudo medicinalis, was measured by means of high-pressure liquid chromatography coupled with electrochemical detection (HPLC-EC). Each segmental ganglion contains 21.3 +/- 2.9 (9) pmol 5-HT [X +/- SEM (N)]. The pharynx contains 7.1 +/- 1.1 (9) pmol 5-HT/mg wet weight; the salivary glands 3.2 +/- 0.9 (10), ventral body wall 2.0 +/- 0.2 (11), and vasofibrous tissue 1.2 +/- 0.2 (11). The blood of hungry leeches contains 8.7 +/- 1.9 (7) nM 5-HT while that of well-fed leeches is 2.2 +/- 0.4 (6) nM. Leeches were injected with the cytotoxic analog of serotonin, 5,7-dihydroxytryptamine (5,7-DHT) producing selective lesions of the peripherally projecting serotonin-containing neurons, and which in turn abolished their feeding behavior. 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.

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“…Not only are they recognizable by their shape and position in the ganglion, but much is already known of their biochemistry: they have been shown to contain 5-hydroxytryptamine (5-HT), and no other biogenic amines (Rude, Coggeshall & Van Orden, 1969;Stuart, Hudspeth & Hall, 1974;Osborne, Briel & Neuhoff, 1972;McCaman, Weinreich & McCaman, 1973) and to synthesize it from tryptophan and from its immediate precursor, 5-hydroxytryptophan (5-HTP) (Hildebrand, Barker, Herbert & Kravitz, 1971;Sargent, 1977). In addition, stimulation of these cells elicits 5-HT release (Willard, 1981), and exogenous 5-HT can mimic some of the effects of Retzius cell stimulation (Lent, 1973;Mason, Sunderland & Leake, 1979).…”

Section: Introductionmentioning

confidence: 99%

The role of 5‐hydroxytryptamine as a transmitter between identified leech neurones in culture.

Henderson¹

1983

The Journal of Physiology

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SUMMARY1. The synthesis, storage, release and synaptic actions of 5-hydroxytryptamine (5-HT or serotonin) were studied in order to characterize the synaptic connexion that develops between pairs of identified neurones dissected from the central nervous system of the leech and maintained in culture. Experiments were made with Retzius cells (which are known to contain 5-HT in vivo) and pressure sensory neurones on which they form chemical synapses in culture.2 When incubated with [3H]5-HT and washed, Retzius cells in culture accumulatedapproximately 100 times more labelled 5-HT than did non-serotonergic cells, and 10 times more than Retzius cell somata acutely isolated from the animal and incubated in vitro. Chlorimipramine, a blocker of5-HT uptake, decreased the amount of[3H]5-HT accumulated by Retzius cells and also caused a reversible increase in the amplitude of the synaptic response in the pressure sensory cell elicited by stimulation of the Retzius cell. 5. Pressure sensory neurones in culture and in vivo responded to 5-HT focally applied by pressure ejection from a micropipette. Small pulses elicited a small, slow hyperpolarization. This response was due, at least in part, to an increase in chloride conductance and desensitized rapidly. With larger pulses, a larger, faster nondesensitizing depolarization was elicited.6. Together, these results provide evidence that 5-HT released from Retzius cells could be responsible for the chemical synaptic potentials seen in pressure sensory neurones in culture.

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The amine and amino acid composition in the Retzius cells of the leechHirudo medicinalis

Cited by 22 publications

References 10 publications

Tryptophan metabolism and the occurrence of amino acids and serotonin in the leech (Hirudo medicinalis) nervous system

Tryptophan metabolism and the occurrence of amino acids and serotonin in the leech (Hirudo medicinalis) nervous system

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

The role of 5‐hydroxytryptamine as a transmitter between identified leech neurones in culture.

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