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PubMed2001

Phenotypic inflammation switch in rats shown by calcitonin gene-related peptide immunoreactive dorsal root ganglion neurons innervating the lumbar facet joints.

STUDY DESIGN: The changes in dorsal root ganglion neurons innervating the L5-L6 facet joint were studied using the retrograde neurotransport method and the immunohistochemistry of calcitonin gene-related peptide in an inflammatory model of rats. OBJECTIVES: To determine by inflammatory stimulation the changes in calcitonin gene-related peptide-immunoreactive dorsal root ganglion neurons innervating the L5-L6 facet. SUMMARY OF BACKGROUND DATA: The rat L5-L6 facet joint is innervated from L1-L5 dorsal root ganglia. The presence of calcitonin gene-related peptide-immunoreactive dorsal root ganglion neurons innervating the L5-L6 facet joint has been confirmed, but the changes in the number and distribution of these neurons caused by inflammation have not been studied. METHODS: Retrograde transport of fluorogold was used in 20 rats: 10 in the control group and 10 in the inflammatory group. Using the dorsal approach, fluorogold crystals were injected into the left L5-L6 facet joint. Then 5 days after application, complete Freund's adjuvant (50 microg Mycobacterium butyricum in oil saline emulsion) was injected into the same L5-L6 facet joint (inflammatory group). Of the total fluorogold-labeled dorsal root ganglion neurons from T13-L6, the number and cross-sectional area of the cell profiles of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive neurons in the bilateral dorsal root ganglia of both groups were evaluated. RESULTS: Fluorogold-labeled neurons were distributed throughout the ipsilateral dorsal root ganglia from L1-L5 in both groups. Of the fluorogold-labeled neurons, the ratios of the calcitonin gene-related peptide-immunoreactive L1, L2, L3, L4, and L5 dorsal root ganglion neurons, respectively, were 17%, 24%, 44%, 56%, and 50% in the control group and 50%, 39%, 51%, 61%, and 56% in the inflammatory group. The ratios of the calcitonin gene-related peptide-immunoreactive L1 and L2 dorsal root ganglion neurons labeled by fluorogold were significantly higher in the inflammatory group than in the control group (P < 0.05). The mean cross-sectional area of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive cells from L1-L5 dorsal root ganglia increased from 621 +/- 64 microm2 to 893 +/- 63 microm2 in the inflammatory group (P < 0.01). CONCLUSIONS: The ratio of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive neurons was significantly higher in the L1 and L2 dorsal root ganglia of the inflammatory group than in those of the control group, and the average cross-sectional area of the cells from L1-L5 dorsal root ganglion increased. Associated with the inflammation in the facet joints, the change in calcitonin gene-related peptide-immunoreactive neuron distribution and the phenotypic switch to large neurons may complicate the mechanism of facet joint inflammatory pain.

Animals↗
PubMed1992

Somatic Acetylcholine Release in Rabbit Nodose Ganglion.

In the rabbit, as in various other species, the presence of a cholinergic vagal afferent contingent has been demonstrated previously using biochemical and immunohistological approaches at the nodose ganglion level, where vagal afferent cell bodies are located. This structure is completely devoid of synaptic contacts. In the present study, somatic acetylcholine release is demonstrated on different types of in vitro rabbit nodose ganglion preparations (fragments of nodose tissue or isolated cell bodies) using chemiluminescent detection. Acetylcholine endogenous content was measured and was shown to be greater in the right nodose ganglion compared to the left. This difference was also observed when spontaneous and potassium chloride-evoked acetylcholine release was measured in extracellular fluid after a 15-min incubation of nodose ganglion fragments. Calcium removal totally blocked this somatic release. A kinetic study of acetylcholine release was also performed by placing the samples (nodose ganglion fragments or isolated cell bodies) directly in front of the photomultiplier, allowing the direct monitoring of (acetylcholine + choline) and choline effluxes. The net acetylcholine release was then deduced by subtraction. Identical kinetics was obtained with the two different nodose ganglion preparations used. This somatic release is calcium-dependent. The occurrence of acetylcholine release at the nodose ganglion level is discussed in comparison with the events occurring in the cholinergic nerve endings. These mechanisms could be implicated in the premodulation of the vagal afferent messages conveyed from the periphery to the central nervous system.

Journal Article↗
PubMed1987

Effect of ganglion blockade on cerebrospinal fluid norepinephrine.

The source of norepinephrine (NE) in CSF has been unclear. It has been suggested that CSF NE indicates central neural noradrenergic tone and is determined differently from plasma NE. If CSF NE depended specifically on NE release in the CNS, then interference with ganglionic neurotransmission would be expected to decrease plasma NE but not CSF NE. Hypotension caused by ganglionic blockade might be expected to increase CSF NE reflexively. We infused the ganglion blocker, trimethaphan, intravenously into anesthetized dogs and measured the effects on mean arterial blood pressure (MAP) and on cisterna magna CSF levels of NE. The results were compared with those obtained on administration of saline, clonidine (2 micrograms/kg), yohimbine (0.25 mg/kg), or nitroprusside and with those obtained when hypotension during ganglion blockade was prevented by concurrent treatment with phenylephrine. Trimethaphan decreased MAP by 40%, arterial NE by 64%, and CSF NE by 61%. Nitroprusside administered intravenously to produce the same 40% depressor response increased arterial NE by 612% and CSF NE by 155%. Prevention of ganglion blockade-induced hypotension using phenylephrine did not prevent the decrease in CSF NE caused by trimethaphan, and when phenylephrine was discontinued, the resulting hypotension was not associated with increases in CSF NE. The similar decreases in plasma NE and CSF NE during ganglionic blockade, and the abolition of reflexive increases in CSF NE during hypotension in ganglion-blocked subjects, cast doubt on the hypothesis that CSF NE indicates central noradrenergic tone and are consistent instead with at least partial derivation of CSF NE from postganglionic sympathetic nerve endings.

Animals↗
PubMed1973

Interaction between picrotoxin and 5-hydroxytryptamine in the superior cervical ganglion of the cat.

1. Electrophysiological techniques were utilized to study the actions of 5-hydroxytryptamine (5-HT) and picrotoxin on the superior cervical ganglion of the cat.2. The intra-arterial administration of 5-HT to the ganglion elicited both depressant and excitatory actions. In low doses (0.01-0.5 mug) the amine produced a depression of ganglionic transmission. In larger doses (2-50 mug) it produced an excitation of ganglion cells (early discharge) and an initial enhancement of transmission, which was followed by depression. Picrotoxin (25-500 mug, i.a.) blocked the initial excitatory effects of 5-HT but did not block the depression. Picrotoxin did not antagonize the excitatory actions of injected cholinomimetic agents or potassium chloride.3. In ganglia conditioned by repetitive stimulation of the preganglionic nerve (30 Hz for 30 s) 5-HT also elicited a late-occurring and very prolonged discharge on certain postganglionic nerves (;spinal') but not on others (external carotid). The late discharge was only partially depressed by picrotoxin.4. Recordings from the surface of the superior cervical ganglion revealed that 5-HT produced three types of ganglionic potentials: (1) an initial transient depolarization which coincided with the early discharge, (2) a late-occurring, prolonged depolarization which coincided with the late discharge, and (3) a hyperpolarization which in some experiments accompanied the depression of transmission. The late depolarization and hyperpolarization were not observed in every experiment. Picrotoxin (25-500 mug) blocked the initial depolarization, but did not block the late depolarization or the hyperpolarization.5. It is concluded the 5-HT can produce three distinct responses in the superior cervical ganglion: a depressant effect and two types of excitation. It seems likely that depression and excitation occur via the activation of different receptors, since picrotoxin selectively blocks the latter. The finding that picrotoxin is a 5-HT antagonist in peripheral ganglia raises the possibility that picrotoxin might also influence tryptaminergic mechanisms in the central nervous system.

Aminobutyrates↗
PubMed1990

Neurophysiological evidence for and characterization of the post-ganglionic innervation of the adrenal gland in the rat.

The aim of this study was to examine and characterize the post-ganglionic innervation of the adrenal gland, using a neurophysiological nerve recording technique. Adrenal multifibre nerve activity was recorded in chloralose-anaesthetized Wistar rats. To test for post-ganglionic nerve activity, trimethaphan, a ganglionic blocker, was given intravenously. About 60% of the adrenal nerve preparations tested responded with a marked decrease in nerve activity (to 52 +/- 11% of pre-trimethaphan activity, P less than 0.01), while other nerves responded with an increase in activity (to 152 +/- 29% of pre-trimethaphan activity, P less than 0.01). Based on these responses, the nerves were considered to contain predominantly post- or preganglionic fibres respectively, and the difference in response to an intravenous injection of trimethaphan between the two groups was significant (P less than 0.01). It was also demonstrated that the post-ganglionic adrenal nerve activity had a greater variability in firing pattern than preganglionic adrenal nerve activity. We also examined whether there was any cardiac rhythmicity in the investigated nerves. There was a weak cardiac rhythmicity in six out of 12 post-ganglionic adrenal nerves, but there was no cardiac rhythmicity in the remaining six post-ganglionic nerves, and we observed no cardiac rhythmicity in preganglionic nerves. In contrast, renal sympathetic nerves showed a profound cardiac rhythmicity. Our results might explain recent histological findings of a direct post-ganglionic innervation of the adrenal cortex. We speculate that this nerve population is involved in steroid synthesis indirectly via regulation of the cortical blood flow or directly via a direct innervation of parenchymal cells in the adrenal cortex.

Adrenal Glands↗
PubMed1974

Concomitant changes in formaldehyde-induced fluorescence of dopamine interneurones and in slow inhibitory post-synaptic potentials of the rabbit superior cervical ganglion, induced by stimulation of the preganglionic nerve or by a muscarinic agent.

1. Dopamine was identified by formaldehyde histochemistry and cytospectrofluorometry in the rabbit's superior cervical ganglion. Dopamine was localized to the intraganglionic ;small intensely fluorescent' cells, and also to the characteristically beaded fibres forming a network in close contact with virtually all ganglion cell bodies. The extensive beaded fibres are therefore presumed to be processes of the small intensely fluorescent cells.2. Changes in the dopamine content of these interneurones were studied by recording alterations in their relative fluorescence intensity in conjunction with changes in the slow inhibitory post-synaptic potential (s.-i.p.s.p.) response of the ganglion to orthodromic nerve input.3. Dopamine content was lower after several hours in vitro even without special stimulation; this was in accord with a regularly observed spontaneous reduction of the s.-i.p.s.p. response.4. After a period of conditioning stimulation of the preganglionic nerve, in the presence of an anticholinesterase agent (eserine) and an inhibitor of catecholamine synthesis (alpha-methyl-p-tyrosine), the s.-i.p.s.p. was selectively and markedly reduced. The dopamine fluorescence in the small intensely fluorescent cell interneurones was also significantly reduced, to a mean value of about 55 or 60% of the fluorescence in the dopamine interneurones of the paired but unstimulated control ganglion. A significant reduction in dopamine fluorescence was always accompanied by a marked loss of s.-i.p.s.p. response; the reverse was not always true.5. Treatment with the muscarinic agent bethanechol for 30 min, with no alpha-methyl-p-tyrosine or eserine present, similarly resulted in reductions in the s.-i.p.s.p. response of the ganglia and in the formaldehyde-induced fluorescence of the dopamine interneurones.6. A functional uptake of extrinsic dopamine by the dopamine interneurones was also demonstrated: temporary exposure to dopamine restored a large fraction of both the s.-i.p.s.p. response and the dopamine fluorescence of the small intensely fluorescent cells, in ganglia already subjected either to the conditioning stimulation of the preganglionic nerve or to the action of bethanechol.7. It is concluded that (a) preganglionic impulses, by a cholinergic muscarinic synaptic action, can induce a release of dopamine from dopamine interneurones (small intensely fluorescent cells) in the superior cervical ganglion, (b) the ability of the ganglion to respond with a s.-i.p.s.p. to orthodromic input may be viewed as being dependent on the supply of functionally releasable dopamine in these interneurones, (c) the functionally releasable transmitter in vitro appears to comprise roughly 50% of the total dopamine content of the interneurones, and (d) the results fulfil some of the requirements of the hypothesis that a dopamine interneurone is activated muscarinically by preganglionic nerve impulses and mediates the production of s.-i.p.s.p. in sympathetic ganglion cells.

Action Potentials↗
PubMed1976

Physiological properties and receptive fields of mechanosensory neurones in the head ganglion of the leech: comparison with homologous cells in segmental ganglia.

A study of the head ganglion of the leech was made to compare the properties of specific sensory cells in this ganglion with those of homologous neurones in the segmental ganglia. 1. In the head ganglion, cells were identified that had electrical properties, sensory modalities and adaptation properties similar to those of touch (T), pressure (P) and nociceptive (N) cells in the segmental ganglia. The cell bodies of these neurones were situated in characteristics positions that could be correlated with those in the segmental ganglia. Several lines of evidence suggested that they were primary sensory neurones. Fewer T, P and N neurones were identified in the head ganglion than would be expected from its six constituent segmental ganglia. 2. The receptive fields of identified T, P and N cells were situated on the external surface of the head and the interior of the mouth with considerable overlap. They were generally smaller in size than those situated on the main part of the body. The receptive fields were also displaced anteriorly so that some of them were situated in segments anterior to those of the innervating cells. 3. The morphology of the sensory cells in the head ganglion was studied by intracellular injection of horseradish perioxidase. The general branching characteristics of the cells and the structural appearance of their processes resembled those of homologous cells in the segmental ganglia. However, the routes taken to the periphery by some of the cells were not constant from head ganglion to head ganglion. This variability was confirmed by electrophysiological evidence, and differed from the constancy seen in segmental sensory cells.

Action Potentials↗
PubMed1981

Selective synapse formation during sprouting after partial denervation of the guinea-pig superior cervical ganglion.

1. The synaptic connexions established by sprouting of intact preganglionic sympathetic axons were examined by intracellular recording in vitro and by observing the sympathetic end organ responses to ventral root stimulation in vivo. 2. The superior cervical ganglion of the guinea-pig was partially denervated (70-85%) by crushing the cervical sympathetic trunk at the level of the subclavian artery, leaving the ansa subclavia intact. The intact nerve carried some preganglionic axons arising from each of the eight spinal cord segments (C8-T7) contributing innervation to the ganglion. 3. During the first 4 weeks after the operation, there was a two-to threefold increase in the number of steps in the synaptic response elicited in individual ganglion cells by graded stimulation of the ansa subclavia. There was also an increase in the amplitude of the synaptic potential elicited by each preganglionic axon. 4. This increase in the synaptic contribution of the intact nerve to neurones in the superior cervical ganglion after partial denervation was attributed to sprouting of residual preganglionic axons. A major contribution from collateral connexions between ganglion cells was ruled out by intracellular recording form neurones during antidromic stimulation of their axons in the inferior post-ganglionic nerve. 5. After sprouting, the specificity of the sympathetic end organ responses elicited by stimulation of the ventral roots of spinal segments T1 and T4 in vivo was indistinguishable from normal, although the strength of these responses increased from just perceptible acutely after partial denervation to near normal 3-6 weeks after the operation, when sprouting was largely complete. 6. These results show that intact preganglionic axons arising from different spinal levels established selective connexions with different classes of ganglion cells during sprouting.

Action Potentials↗
PubMed1983

Maintenance of cholinergic neurones and synapses in the ciliary ganglion of aged rats.

The ciliary ganglion has been examined in young adult (1.5-2 months) and aged rats (24-28 months). In young adult rats the ganglion contains about 200 neurones, each of which is innervated by 1-4 preganglionic axons (mean, 2.2). In these animals about 2-3 X 10(3) synaptic boutons were observed per square millimetre in thin sections of the ganglion; synapses were located mainly on finger-like extensions of cell bodies and on dendrites. The size of the ganglion cell population, the number of inputs per ganglion cell, the density of synaptic boutons and the amplitude of post-synaptic potentials recorded intracellularly did not differ significantly between the young and aged animals. It thus appears that the neuronal population of the ciliary ganglion and the cholinergic synapses received by ganglion cells are remarkably stable well into old age.

Aging↗
PubMed1983

Reduced activity during development delays the normal rearrangement of synapses in the rabbit ciliary ganglion.

The number of preganglionic axons that innervate individual ciliary ganglion cells has been investigated after cutting one or both optic nerves in new-born rabbits. In agreement with previous work (Johnson & Purves, 1981), ciliary ganglion cells in normal rabbits lose, on average, about one-half of their inputs from preganglionic axons during the first month of post-natal life. Although severing one optic nerve at birth abolished the subsequent appearance of the direct pupillary light response on that side, ciliary ganglion cells of normal neonatal rabbits are driven synaptically in the absence of direct retinal illumination when tested in vivo. This tonic activity persisted for at least 3 months after interruption of the optic nerve at birth. Thus neonatal optic nerve section reduced, but did not eliminate, synaptic activation of ciliary ganglion cells. Optic nerve section at birth delayed the elimination of synaptic connexions in the ipsilateral but not the contralateral ciliary ganglion. Through the first 4 post-natal weeks ciliary ganglion cells on the operated side had, on average, more than the normal number of inputs from preganglionic axons. By 8 weeks of age, however, the normal number of connexions was established in spite of the unilateral visual deprivation. The elimination of connexions in ganglia on the unoperated side followed a normal time course. The effect of bilateral optic nerve section on synaptic rearrangement was the same as the ipsilateral effect after cutting only one optic nerve. It is concluded that the rate of synaptic rearrangement in this ganglion is slowed by a chronic reduction of synaptic activity.

Animals↗
PubMed1992

Aminergic and peptidergic elements and actions in a cardiac parasympathetic ganglion.

Correlated histochemical, immunocytochemical, and electrophysiological experiments have been undertaken to identify putative neurotransmitter-neuromodulator substances in cells and fibers in the parasympathetic cardiac ganglion of the mudpuppy, Necturus maculosus, and to determine the action of these agents on the properties of the parasympathetic postganglionic neurons. The mudpuppy cardiac ganglion contains two neuron types: large parasympathetic postganglionic neurons and smaller intrinsic neurons initially identified as small intensely fluorescent cells. We have shown that the postganglionic neurons contain both acetylcholine and a galanin-like neuropeptide. Also, we have demonstrated that the intrinsic neurons contain a number of different biogenic amines such as dopamine and serotonin, as well as neuropeptides including a substance P-like peptide and a galanin-like peptide. The results of these studies indicate that the anatomical and histochemical organization of the mudpuppy cardiac ganglion is more complex than that seen in other amphibians and is very similar to that found in most mammalian species. Previously, we showed that galanin has actions that make it of interest as a potential inhibitory neurotransmitter in the mudpuppy cardiac ganglion. Galanin hyperpolarizes and decreases membrane excitability in most parasympathetic neurons. Here we show that galanin initiates membrane hyperpolarization by activating a voltage- and time-dependent potassium conductance. We also present the initial results of ongoing studies which indicate that calcitonin gene-related peptide can depolarize some of the parasympathetic neurons as well as evidence that serotonin initiates depolarization in many parasympathetic neurons. This serotonin-induced depolarization consists of an initial transient depolarization followed by a longer, more slowly developing depolarization. Action potential activity is stimulated during the initial period of depolarization, but depressed during the later, slow depolarization. The results of these electrophysiological experiments suggest that many of the bioactive substances that have been identified in the different cells and nerve fibers within the cardiac ganglion affect the excitability of the postganglionic neurons. In conclusion, we suggest that the results of the studies summarized in this review demonstrate that the cardiac ganglion in the mudpuppy is not simply a relay station. Rather, the cardiac ganglion has a complex organization and exhibits a diversity of physiological responses, indicating that it very likely is another site of integration for control of cardiac function.

Animals↗
PubMed1987

Retrograde effects of target atrophy on submandibular ganglion neurons.

1. To study the retrograde effects of changes in target tissue upon the innervating nerve supply, we have examined the parasympathetic submandibular ganglion of the adult rat. Neurons of this ganglion innervate the submandibular and sublingual salivary glands. 2. Ligating the salivary ducts leads to rapid and prolonged salivary gland cell atrophy. 3. Duct ligations, without direct injury to the glandular nerve supply, initially produced few alterations in the ganglion. After 8 wk, however, neuron number was reduced by 50%. The numbers of presynaptic inputs/neuron and synapses/neuron perimeter were not affected by the cell loss. 4. After 1 wk of duct ligation in which the glandular nerve supply was intentionally damaged, some ganglionic neurons have lost all presynaptic inputs, suggesting synaptic disjunction. This is followed at 3 wk by a 40% decrease in neuron number and an increase in the number of inputs per (remaining) ganglion cell. However, the number of synapses/neuronal profile was unchanged. 5. Thus axotomy plus target atrophy causes synaptic disjunction, neuron cell death, and input rearrangement, presumably due to a combination of direct injury effects and an abrupt loss of peripheral trophic supplies. 6. In contrast, target atrophy alone produced more gradual changes in submandibular ganglion neurons. Only prolonged target atrophy leads to a decrease in the number of ganglionic neurons, perhaps due to the gradual loss of peripheral trophic supplies. However, other features, such as the number of inputs/cell and the number of synapses/neuron perimeter, remain unaltered. Evidently, the gradual loss of trophic support does not result in synaptic disjunction to the degree needed to produce presynaptic input rearrangement.

Animals↗
PubMed1989

Histogenetic study of the vestibular ganglion in the developing chick embryo by lectin-horseradish peroxidase methods.

Hatchery eggs of White Leghorn hens were incubated and the vestibular ganglion cells of 3.5- to 6-day-old chick embryos were studied by the lectin-horseradish peroxidase methods (WGA, UEA-1). In the 3.5-day-old chick embryos, the facial-acoustic ganglion mass was recognized close to the otic vesicle. The statoacoustic ganglion reacted to lectins on the rhombencephalic side, indicating that glycoconjugates play a role in the nerve connection between ganglion and rhombencephalon. In the 4-day-old chick embryos, a strong reaction to lectins was observed on the ganglion cell membrane of the geniculate and statoacoustic ganglions, suggesting that glycoconjugates may be related to their differentiation. In 4- and 5-day-old chick embryos, the mesenchymal tissue showed a strong reaction to lectins, suggesting that it plays an important part in the differentiation of the vestibular ganglion.

Animals↗
PubMedDate not supplied

A histochemical study of cerebral cortical vessels and ganglionic vessels of the caudatoputamen in aging normotensive rats.

The goal was to describe the metabolic profile of ganglionic and cortical arteries and arterioles in aging normotensive male rats. Five enzymes indicative of key metabolic pathways in the vessel walls were semiquantitatively evaluated using bright-field histochemical microscopy. Lactate dehydrogenase showed significant reactivity which increased with vessel diameter in cortical and ganglionic vessels in all age groups tested. Succinate dehydrogenase and cytochrome oxidase showed little reactivity in both cortical and ganglionic vessels, suggesting a reduced role for aerobic metabolic pathways. Myosin ATPase reactivity was high in cortical and ganglionic vessels. Only this enzyme showed an increased reactivity that was correlated with the age and diameter of the vessel. Glucose-6-phosphate dehydrogenase reactivity was more pronounced in cortical than ganglionic vessels, suggesting that the hexose-monophosphate-shunt may be more active in the cortical vessels. There were no regional differences in enzyme reactivity throughout the caudatoputamen. In conclusion, both the cortical and ganglionic vessels are metabolically active, with significant anaerobic glycolysis, and reduced, but observable capacity for aerobic metabolism. The decreased myosin ATPase reactivity and the low level of glucose-6-phosphate dehydrogenase reactivity in the ganglionic arterioles of senescent rats may contribute to the susceptibility of these vessels to cerebrovascular accidents.

Adenosine Triphosphatases↗
PubMed1994

Major species variation in the expression of galanin messenger ribonucleic acid in mammalian celiac ganglion.

To determine whether galanin may be a sympathetic neurotransmitter in the pancreas of primates and rats as well as dogs, the expression of the galanin gene was examined in the celiac ganglion of these species by in situ hybridization and RIA. Intense hybridization signal for galanin messenger RNA (mRNA) was observed in every neuronal cell body of the dog celiac ganglion. However, significant hybridization signal for galanin mRNA was seen in only 24 +/- 5% of celiac ganglion cell bodies in monkeys and was absent in rats. RIA of celiac ganglion extracts confirmed this species variation; galanin-like immunoreactivity was highest in dog celiac ganglion (158 +/- 13 pmol/g), present in monkeys (34 +/- 7 pmol/g), and undetectable in rats (< 0.8 pmol/g). In contrast, the celiac ganglia of all three species showed intense hybridization signal for neuropeptide-Y (NPY) mRNA in the majority of neuronal cell bodies (dog, 82 +/- 4%; monkey, 92 +/- 2%; rat, 91 +/- 3%), and the celiac ganglion NPY immunoreactivity content was high in all three species (dog, 1064 +/- 155 pmol/g; monkey, 3180 +/- 745 pmol/g; rat, 3412 +/- 347 pmol/g). Thus, there is a marked species variation in the expression of the galanin, but not the NPY, gene in the celiac ganglion of dogs, monkeys, and rats. These data suggest that galanin is an important sympathetic neurotransmitter in the pancreatic islets of dogs, but not those of primates or rats.

Animals↗
PubMed1999

Retinoids are produced by glia in the lateral ganglionic eminence and regulate striatal neuron differentiation.

In order to identify molecular mechanisms involved in striatal development, we employed a subtraction cloning strategy to enrich for genes expressed in the lateral versus the medial ganglionic eminence. Using this approach, the homeobox gene Meis2 was found highly expressed in the lateral ganglionic eminence and developing striatum. Since Meis2 has recently been shown to be upregulated by retinoic acid in P19 EC cells (Oulad-Abdelghani, M., Chazaud, C., Bouillet, P., Sapin, V., Chambon, P. and Dollé, P. (1997) Dev. Dyn. 210, 173-183), we examined a potential role for retinoids in striatal development. Our results demonstrate that the lateral ganglionic eminence, unlike its medial counterpart or the adjacent cerebral cortex, is a localized source of retinoids. Interestingly, glia (likely radial glia) in the lateral ganglionic eminence appear to be a major source of retinoids. Thus, as lateral ganglionic eminence cells migrate along radial glial fibers into the developing striatum, retinoids from these glial cells could exert an effect on striatal neuron differentiation. Indeed, the treatment of lateral ganglionic eminence cells with retinoic acid or agonists for the retinoic acid receptors or retinoid X receptors, specifically enhances their striatal neuron characteristics. These findings, therefore, strongly support the notion that local retinoid signalling within the lateral ganglionic eminence regulates striatal neuron differentiation.

Animals↗
PubMed1992

Role of PGE2 in neurotransmission from pre- to post-ganglionic hypogastric nerves of guinea pigs.

The hypogastric nerve to guinea pig vas deferens was stimulated pre- or post-ganglionically by adjusting the position of the suction electrode. Both stimulations induced a biphasic contraction consisting of a rapid transient phase and a delayed tonic phase. Indomethacin partially inhibited the contraction induced by pre-ganglionic stimulation, but did not inhibit that induced by post-ganglionic stimulation. Prostaglandin (PG) E2 counteracted the inhibitory effect of indomethacin. Mepacrine also inhibited the contraction induced by pre-ganglionic stimulation. Arachidonic acid and PGE2 both reversed the inhibition. The PGE2-receptor antagonist SC-19220 inhibited the contraction induced by pre-ganglionic, but not post-ganglionic nerve stimulation. These results suggested that endogenous PGE2 is important in neurotransmission in the pelvic ganglion of guinea pigs.

Animals↗
PubMed2003

Morphological characterization of skin ganglion-like cells in Djungarian hamsters (Phodopus sungorus).

Characteristic ganglion-like cell proliferation observed in the skin of Djungarian hamsters was investigated using 24 male and 24 female hamsters, 1-6 months of age, to examine the anatomic location of these ganglion-like cells and their morphologic features. One abdominal skin tumor composed of these cells and resembling proliferative fasciitis in humans was also examined. Skin ganglion-like cells were rarely observed in young animals but increased in number and extent with age, especially in males. These cells were frequently seen in the ventral and medial regions of the trunk and legs rather than in the dorsal and lateral regions. Light microscopic examination of these ganglion-like cells revealed abundant vesicular basophilic cytoplasm with delicate intracytoplasmic silver stain-positive fibrils. Ultrastructurally, these cells contained abundant rough endoplasmic reticulum and Golgi complexes with dilated cisternae; intracellular collagen fibrils were present within these cisternae. Heat shock protein 47, beta-tubulin, and androgen receptor were expressed in these cells. The morphologic features of cells of one tumor resembling human proliferative fasciitis were identical to those observed in ganglion-like cells. The results of the present study suggest that these ganglion-like cells are derived from intrinsic undifferentiated mesenchymal cells in the dermis or subcutaneous adipose tissue and that any tumor-like lesion they form should be regarded as an abnormal proliferative lesion of skin ganglion-like cells rather than as proliferative fasciitis or fibroma.

Abdominal Neoplasms↗