Modulation by C2 ceramide of the nicotinic transmission within the coeliac ganglion in the rabbit

doi:10.1016/S0306-4522(02)00760-1

Neuroscience

Volume 116, Issue 3, 17 February 2003, Pages 753-759

https://doi.org/10.1016/S0306-4522(02)00760-1 Get rights and content

Abstract

We have investigated the modulation by ceramide of the nicotinic activation of the prevertebral sympathetic neurons. Our study was performed in vitro in rabbit isolated coeliac ganglion, using intracellular recording techniques. We have used C₂ ceramide, a permeant analog of ceramide. The effects of C₂ ceramide were first assessed when nicotinic activation was elicited without modulatory mechanisms (fast excitatory postsynaptic potentials triggered by stimulation of the thoracic splanchnic nerves with a single pulse). In all the neurons tested, C₂ ceramide triggered an increase in the amplitude of the fast excitatory postsynaptic potentials demonstrating a direct facilitatory effect on the nicotinic activation. We then investigated the effects of C₂ ceramide on modulatory mechanisms of this activation. These mechanisms occur when a train of pulses of supramaximum intensity is applied on the splanchnic nerves. During the train, a gradual depression of fast nicotinic activation occurred: the pulses failed to systematically elicit action potentials. We have previously demonstrated that this regulatory phenomenon is partly modulated by nitric oxide which exerts a dual effect: facilitation or inhibition of the nicotinic activation. In all the neurons tested, C₂ ceramide decreased the number of action potentials fired during a train of pulses, demonstrating an indirect inhibitory effect on the nicotinic activation. The use of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (nitric oxide scavenger) suppressed the inhibitory effect of C₂ ceramide, demonstrating that this effect is mediated through the nitric oxide pathway. C₂ dihydro-ceramide, an inactive analog of ceramide, was without effect on the nicotinic activation of the ganglionic neurons. These results demonstrate that ceramide exerts a complex modulation of the nicotinic activation of the prevertebral neurons: direct facilitation and indirect inhibition involving the nitric oxide pathway. In fact, C₂ ceramide plays a key gating role in the dual effect of the nitric oxide pathway by activating the inhibitory effect. The existence of this gating mechanism involving ceramide and nitric oxide opens new perspectives in terms of our understanding of the modulation of synaptic transmission within the prevertebral ganglia. Our study demonstrates that sphingolipids are involved in complex modulations of the synaptic activation within the prevertebral ganglia, and thus contribute to their integrative properties.

Section snippets

Experimental animals and in vitro preparation

Thirty-five rabbits (Marras, 13,140 Lambesc, France) of either sex ranging from 1.5–2.0 kg were used. The animals were killed by procedures approved by the French Ministry of Agriculture and in conformity with the European Communities Council Directive (86/609/EEC). The left thoracic splanchnic nerves and the left coeliac ganglion were dissected out. The preparation was placed in an organ bath superfused with a modified Krebs solution having the following composition (in mM): 120 NaCl, 5 KCl, 1

Results

This study was performed on 48 neurons which were synaptically activated by stimulation of the splanchnic nerves. Their resting membrane potential ranged from −38 to −70 mV, with a mean value of −51.0±1.4 mV (mean±S.E.M.). These neurons never displayed any spontaneous EPSPs or action potentials.

Discussion

Our study demonstrates that C₂ ceramide exerts complex modulatory effects on nicotinic fast synaptic activation of prevertebral ganglionic neurons. These effects include direct facilitation and indirect inhibition involving the NO pathway.

Acknowledgements

The authors wish to thank G. Ivaldi for the construction of the in vitro setup, M. Manneville for the construction of the electronic devices and Michael Paul for revising the English. This work was supported by the CNRS, INRA and University Aix-MarseilleIII.

References (24)

S.M. Bajjalieh et al.
Synaptic vesicle ceramide kinasea calcium-stimulated lipid kinase that co-purifies with brain synaptic vesicles
J Biol Chem
(1989)
V. Campbell et al.
The role of ceramide in the modulation of intracellular Ca2+ levels by interleukin 1 beta in rat cortical synaptosomes
Cytokine
(2000)
Y.A. Hannun et al.
Sphingosine inhibition of protein kinase C activity and of phorbol dibutyrate binding in vitro and in human platelets
J Biol Chem
(1986)
X.A. Li et al.
High density lipoprotein binding to scavenger receptor, class B, type I activates endothelial nitric-oxide synthase in a ceramide-dependent manner
J Biol Chem
(2002)
A.H. Merrill et al.
Sphingolipids—the enigmatic lipid classbiochemistry, physiology, and pathophysiology
Toxicol Appl Pharmacol
(1997)
J.P. Miolan et al.
The mammalian sympathetic prevertebral gangliaintegrative properties and role in the nervous control of digestive tract motility
J Auton Nerv Syst
(1996)
K. Pahan et al.
Sphingomyelinase and ceramide stimulate the expression of inducible nitric-oxide synthase in rat primary astrocytes
J Biol Chem
(1998)
N. Quinson et al.
Nerve-induced release of nitric oxide exerts dual effects on nicotinic transmission within the coeliac ganglion in the rabbit
Neuroscience
(1998)
S. Spiegel et al.
Signal transduction through lipid second messengers
Curr Opin Cell Biol
(1996)
S.N. Yang
Ceramide-induced sustained depression of synaptic currents mediated by ionotropic glutamate receptors in the hippocampusan essential role of postsynaptic protein phosphatases
Neuroscience
(2000)

J.L. Bruses et al.

Membrane lipid rafts are necessary for the maintenance of the (alpha)7 nicotinic acetylcholine receptor in somatic spines of ciliary neurons

J Neurosci

(2001)

C. Colina et al.

Ceramide and sphingosine have an antagonistic effect on the plasma-membrane Ca2+-ATPase from human erythrocytes

Biochem J

(2002)

Cited by (16)

Physiology of Prevertebral Sympathetic Ganglia
2012, Physiology of the Gastrointestinal Tract, Two Volume Set
Physiology of Prevertebral Sympathetic Ganglia
2012, Physiology of the Gastrointestinal Tract
Roles for dysfunctional sphingolipid metabolism in Alzheimer's disease neuropathogenesis
2010, Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Sphingolipids in the membranes of neurons play important roles in signal transduction, either by modulating the localization and activation of membrane-associated receptors or by acting as precursors of bioactive lipid mediators. Activation of cytokine and neurotrophic factor receptors coupled to sphingomyelinases results in the generation of ceramides and gangliosides, which in turn, modify the structural and functional plasticity of neurons. In aging and neurodegenerative conditions such as Alzheimer's disease (AD), there are increased membrane-associated oxidative stress and excessive production and accumulation of ceramides. Studies of brain tissue samples from human subjects, and of experimental models of the diseases, suggest that perturbed sphingomyelin metabolism is a pivotal event in the dysfunction and degeneration of neurons that occurs in AD and HIV dementia. Dietary and pharmacological interventions that target sphingolipid metabolism should be pursued for the prevention and treatment of neurodegenerative disorders.
From biological gastroenterology to fundamental neurosciences: How studies in gastric emptying have led to the discovery of a new mechanism of neuronal functioning
2010, Gastroenterologie Clinique et Biologique
Gastric emptying undergoes complex regulation by the nervous system, which organizes in particular the inhibition of duodenum motility after a rise in intra-gastric pressure: the gastro-duodenal inhibitory reflex. It was first shown in mammals that this reflex could be organized by a sympathetic ganglion, the coeliac plexus. The excitation of gastric mechanosensitive fibres leads in this ganglion to the release of a neurotransmitter, which in turn activates ganglionic neurones leading to inhibition of the duodenum contractions. It rapidly became apparent that this reflex presented striking properties since it was organized in the absence of action potentials along the nerve fibres. Then it was shown that the neurotransmitter released in the coeliac plexus was gaseous: nitric oxide (NO). The nature of the mechanism conducting, without action potentials, the excitation along the nerve fibres was recently determined. This mechanism necessitates the integrity of particular areas of the neuronal membrane (the lipid rafts) and the activation in cascade of the following second messenger sequence: ceramide, calcium, NO and guanosine cyclic monophosphate (c-GMP). These results show how studies in biological gastroenterology have led to the rethinking of one of the central dogmas in neuroscience according to which excitation is only conducted along the nerves by the action potential.
La vidange gastrique est régulée de manière complexe par le système nerveux. Celui-ci organise en particulier l’inhibition de la motricité duodénale après une augmentation de pression intragastrique : le réflexe gastro-duodénal inhibiteur. Il a initialement été montré chez le mammifère que ce réflexe peut être organisé par un ganglion sympathique, le plexus cœliaque. L’excitation des fibres gastriques mécanosensibles provoque la libération dans ce ganglion d’un neuromédiateur qui va activer des neurones ganglionnaires provoquant ainsi une inhibition du duodénum. Il est rapidement apparu que ce réflexe possède des propriétés atypiques puisqu’il est organisé en l’absence de potentiel d’action le long des fibres nerveuses. Puis il a été démontré que le neuromédiateur libéré dans le plexus cœliaque est gazeux : le monoxyde d’azote. La nature du mécanisme conduisant, sans potentiel d’action, l’excitation le long des fibres nerveuses a été déterminée récemment. Ce mécanisme nécessite l’intégrité de zones particulières de la membrane (les rafts lipidiques) et l’activation en cascade de la séquence de seconds messagers suivants : céramide, calcium, monoxyde d’azote et guanosine monophosphate cyclique. Ces résultats montrent comment des études en gastroentérologie biologique ont débouché sur la remise en cause d’un des dogmes majeurs des neurosciences qui stipule que l’excitation est uniquement transmise le long des nerfs par le potentiel d’action.
The mammalian sympathetic prevertebral ganglia: Models for the study of neuronal networks and basic neuronal properties
2009, Autonomic Neuroscience: Basic and Clinical
The mammalian sympathetic prevertebral ganglia regulate various visceral functions and in particular the digestive tract motility. Several integrative properties of these ganglia have been described: convergence of central inputs, projection of visceral inputs at the pre- and post synaptic level and pacemaker activity of the neurones. This review presents the results obtained on another integrative property which has been widely studied over the last 10 years: the modulation of the fast central inputs by neuromodulators such as nitric oxide, ceramide and GABA. These substances facilitate or inhibit the fast central inputs through complex interrelated actions. We also present striking results recently obtained during the study of a regulatory reflex of the digestive tract motility organized by the prevertebral ganglia: the gastro-duodenal inhibitory reflex. During this reflex, the neurotransmitter released by the visceral afferent fibres to activate the ganglionic neurones is gaseous: nitric oxide. Moreover, the mechanism conducting the excitation along the afferent and efferent fibres is independent of action potentials. This mechanism requires the integrity of the membrane lipid rafts and the activation in cascade of the following second messenger sequence: ceramide, calcium, nitric oxide and guanosine 3′, 5′-cyclic monophosphate. The existence of this mechanism gives grounds for rethinking one of the central dogmas in neuroscience according to which excitation is only conducted along nerves by an electrical phenomenon, the action potential. All these results strengthen the role of the prevertebral ganglia as a model for the study of neuronal networks and basic neuronal properties.
Ceramide elevates 12-hydroxyeicosatetraenoic acid levels and upregulates 12-lipoxygenase in rat primary hippocampal cell cultures containing predominantly astrocytes
2008, Neurochemistry International
We report, exogenous addition of ceramide significantly increases 12-hydroxyeicosatetraenoic acid [12-(S)-HETE] levels, in a dose-dependent manner. 12-(S)-HETE levels, in 20, 30 and 40 μM ceramide exposed rat primary hippocampal cell cultures containing predominantly astrocytes and few neurons and other glial cells (the cultured hippocampal cells were predominantly astrocytes amounting to over 99% of total cells with few neurons and other glial cells) amounted to 207, 260 and 408% of the controls, respectively. However, dihydroceramide, an inactive analog of ceramide did not alter the levels of 12-(S)-HETE. Ceramide also increased the mRNA and protein expression, and activity of 12-lipoxygease (12-LOX) needed for the synthesis of 12(S)-HETE. These results indicate a possible link between ceramide and 12-LOX pathway. However, ceramide did not alter expression of 5-lipoxygenase (5-LOX), another member of the lipoxygenase family. However, ceramide upregulated expression of cytosolic phospholipase-A₂ (cPLA₂) and cyclooxygenase-2 (COX-2). Further, ceramide caused a significant increase in the levels of reactive oxygen species (ROS). Ceramide-mediated generation of ROS was inhibited by baicalien but not by indomethacin. In addition, ceramide treated cells exhibited increased mRNA expression of DNA damage induced transcript3 (Ddit3). This report which demonstrate induction of pro-carcinogenic 12-LOX pathway by an anticancer ceramide, may be relevant to cancer biologists studying drug resistant tumors and devising potent anticancer therapeutic strategies to treat drug resistant tumors. These results indicate possibility of 12-LOX involvement in ceramide-mediated generation of ROS and cellular oxidative stress. Induction of 12-LOX pathway by ceramide may have implications in understanding pathophysiology of neurodegenerative diseases involving ROS generation and inflammation.

View all citing articles on Scopus

View full text

Research paperModulation by C2 ceramide of the nicotinic transmission within the coeliac ganglion in the rabbit

Abstract

Section snippets

Experimental animals and in vitro preparation

Results

Discussion

Acknowledgements

J Biol Chem

Cytokine

J Biol Chem

J Biol Chem

Toxicol Appl Pharmacol

J Auton Nerv Syst

J Biol Chem

Neuroscience

Curr Opin Cell Biol

Neuroscience

Membrane lipid rafts are necessary for the maintenance of the (alpha)7 nicotinic acetylcholine receptor in somatic spines of ciliary neurons

J Neurosci

Ceramide and sphingosine have an antagonistic effect on the plasma-membrane Ca2+-ATPase from human erythrocytes

Biochem J

Research paper
Modulation by C₂ ceramide of the nicotinic transmission within the coeliac ganglion in the rabbit