Identification of small intensely fluorescent (SIF) cells as chromaffin cells in bullfrog sympathetic ganglia

Weight, Forrest F.; Weitsen, Howard A.

doi:10.1016/0006-8993(77)90989-1

Cited by 35 publications

(9 citation statements)

References 34 publications

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“…If muscarinic hyperpolarization requries neurotransmitter release from an interneurone, the response should have been blocked. We therefore conclude, in agreement with Weight & Padjen (1973), Weight & Weitsen (1977), Weight & Smith (1980), Horn & Dodd (1981), Yavari & Weight (1981), Dodd & Horn (1983) and Weight (1983), that the slow i.p.s.p. is generated by the direct muscarinic action of ACh on ganglionic neurones.…”

Section: Adrenergic Interneurone Hypothesissupporting

confidence: 88%

“…(Libet & Kobayashi, 1974 Weight & Padjen (1973), Weight & Weitsen (1977), Weight & Smith (1980), Horn & Dodd (1981), Yavari & Weight (1981), Dodd & Horn (1983) and Weight (1983), that the slow i.p.s.p. is generated by the direct muscarinic action of ACh on ganglionic neurones.…”

Section: Adrenergic Interneurone Hypothesismentioning

confidence: 99%

“…The evidence from more recently publised reports indicates that the slow i.p.s.p. is a direct muscarinic response (Weight & Weitsen, 1977;Weight & Smith, 1980;Horn & Dodd, 1981;Yavari & Weight, 1981;Dodd & Horn, 1983;Weight, 1983).…”

Section: Introductionmentioning

confidence: 99%

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α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

Rafuse

Smith

1986

British J Pharmacology

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Section: Adrenergic Interneurone Hypothesissupporting

confidence: 88%

Section: Adrenergic Interneurone Hypothesismentioning

confidence: 99%

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α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

Rafuse

Smith

1986

British J Pharmacology

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“…Theophylline increased slow IPSP amplitude in 16 of 17 experiments. Since theophylline can affect transmitter release (16), we also tested the effect of theophylline on the response to methacholine (MCh), an agonist that directly activates the postsynaptic receptors involved in generating the slow PSP's (8,17). The effects of theophylline on the MCh-induced hyperpolarization and depolarization were similar to its effects on the slow IPSP and the slow EPSP, respectively ( Fig.…”

mentioning

confidence: 99%

Synaptic Potentials in Sympathetic Ganglia: Are They Mediated by Cyclic Nucleotides?

Busis

Weight

Smith

1978

Science

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The hypothesis that cyclic nucleotides are intracellular second messengers mediating the generation of synaptic potentials was studied in the sympathetic ganglia of the bullfrog. Synaptic potentials and the effect of administering cyclic nucleotides and agents which affect cyclic nucleotide metabolism were recorded by the sucrose gap technique. The administration of adenosine 3',5'-monophosphate (cyclic AMP), guanosine 3',5'-monophosphate (cyclic GMP), or several of their derivatives produced little or no change in membrane potential. Prostaglandin E1 did not block the generation of postsynaptic potentials. Theophylline produced membrane effects that were different from those associated with postsynaptic potential generation; it also reduced the slow excitatory postsynaptic potential (EPSP) and potentiated the slow inhibitory postsynaptic potential (IPSP). The administration of papaverine, however, reduced both the slow EPSP and the slow IPSP. Although synaptic stimulation increases both cyclic GMP and cyclic AMP in these neurons, these results raise the possibility that these cyclic nucleotides may have functionla roles other than mediation of synaptic potentials.

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“…Fujimoto (1967) described synapses on SIF cells of Bufo vulgaris, and Hill et al (1975) and Watanabe and Burnstock (1976b) described them in Limnodynustes dumerili, whereas Piezzi and Rodriguez Echandia (1968) in Bufo arenarum and Weight and Weitsen (1977) in the bullfrog claimed that SIF cells were not innervated. However, also in the bullfrog, Dunn and Marshall (1985) found that 20-30% of SIF cells in clusters responded to a preganglionic stimulation, while found that SIF cells isolated or in small clusters were not innervated; however, synapses were frequent in large clusters.…”

Section: Ultrastructural Studies Of Tranemitter Releasementioning

confidence: 99%

Synaptic organization of amphibian sympathetic ganglia

Lascar

Eugène

Taxi

1996

Microsc. Res. Tech.

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The synaptic organization of the amphibian sympathetic ganglia was studied, especially in the last two abdominal paravertebral ganglia of the frog. These ganglia appear to form a monosynaptic relay, not containing interneurons. They consist of two systems working in parallel: the principal neurons, by far the most numerous, and a small number of chromaffin (i.e., SIF) cells, usually arranged in clusters. Each principal neuron is innervated by a preganglionic branch forming a set of cholinergic synapses which exhibit classical ultrastucture. The only peculiarity is the presence of a subsynaptic apparatus in a variable percentage of synaptic complexes. Electro‐physiological studies have demonstrated that synaptic transmission is due to ACh release and involves several postsynaptic potentials. Moreover, the principal neurons are of two types, B and C, whose preganglionic axons and their own axons have different conduction velocities. C neurons tend to be small in diameter, and B neurons are larger, but the size distribution of the two populations overlaps. More recently, it was demonstrated that these two neuronal systems have different immunocytochemical features. The C preganglionic fibers contain an LHRH‐like peptide, which is responsible for late synaptic events. The B preganglionic fibers contain CGRP, whose role has not yet been established. The principal neurons all contain adrenaline, but neuropeptide Y is also present in C neurons and could be a second transmitter at peripheral junctions. SP‐containing fibers also pass through the ganglia, but give rise to intraganglionic synapses only rarely, except in the celiac plexus. Galanin can coexist with neuropeptide Y in certain C neurons. Numerous principal neurons are immunoreactive for VIP. Chromaffin cells contain noradrenaline and metenkephalin, and some contain SP or LHRH; they are endocrine cells controlled by preganglionic fibers and can have a modulatory effect on principal neurons endowed with appropriate receptors. The accessibility of frog abdominal ganglia and the anatomical separation of B and C preganglionic fiber pathways provide interesting systems in which to carry out experimentation on the stability and specificity of synaptic contacts. After postganglionic axotomy, the majority of synapses disappear by disruption of synaptic contacts. There is a certain discrepancy between the recovery of synaptic transmission and the reappearance of morphologically identifiable synapses, suggesting that a certain amount of transmission is possible at contacts devoid of synaptic complexes. The selective deafferentation of B or C neurons showed that the subsynaptic apparati are mainly found at B neuron synapses. The course of reinnervation following selective deafferentation reveals the existence of different specificities at B and C synapses: C neurons are easily reinnervated by B preganglionic fibers, whereas C fibers appear fairly ineffective at reinnervating B neurons, even after a long interval. Attempts were made to reinnervate ganglionic neurons...

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Identification of small intensely fluorescent (SIF) cells as chromaffin cells in bullfrog sympathetic ganglia

Cited by 35 publications

References 34 publications

α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

Synaptic Potentials in Sympathetic Ganglia: Are They Mediated by Cyclic Nucleotides?

Synaptic organization of amphibian sympathetic ganglia

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Identification of small intensely fluorescent (SIF) cells as chromaffin cells in bullfrog sympathetic ganglia

Cited by 35 publications

References 34 publications

α2‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

α2‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

Synaptic Potentials in Sympathetic Ganglia: Are They Mediated by Cyclic Nucleotides?

Synaptic organization of amphibian sympathetic ganglia

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Product

Resources

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α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia

α₂‐Adrenergic hyperpolarization is not involved in slow synaptic inhibition in amphibian sympathetic ganglia