Superior Cervical Ganglion Of Cat Research Articles

Modulation of cyclic-AMP synthesis in the cat superior cervical ganglion by short term presynaptic stimulation

Fluorescence microscopic examination of five hamster superior cervical ganglia demonstrated that there were 223 ± 31 small, intensely fluorescent (SIF) cells per ganglion, equivalent to 140 ± 26 SIF cells per milligram tissue (wet weight). Incubation of hamster superior cervical ganglia (SCG) in vitro with 50 μm l-isoproterenol increased cyclic AMP concentrations to 622% of control values. Administration of 50 μm dopamine was without effect. Comparison with other species suggests that the superior cervical ganglia of three rodents—the hamster, guinea pig, and rat—differ significantly from those of other species in their morphologic and biochemical properties.

Effect of lithium and rubidium on the ganglionic inhibitory action of norepinephrine

Close intraarterial infusion of lithium chloride (2 and 4 mEq/kg) transiently suppressed evoked postganglionic potentials in the superior cervical ganglion of the cat; lower doses (0.5 and 1 mEq/kg) had no effect on transmission. Potentiation of the ganglionic inhibitory effect of norepinephrine (NE) occurred at plasma concentrations of lithium equivalent to those found to be therapeutic in man. Concurrent administration of lithium (1 mEq/kg) and doxepin (25 mcg/kg) produced greater facilitation of the ganglionic suppressant effect of NE than either lithium or doxepin alone. Rubidium chloride (0.1, 0.5 and 1 mEq/kg) produced temporary blockade of ganglionic transmission; lower doses (0.05 and 0.075 mEq/kg) did not exhibit a ganglioplegic effect. Reduction of the ganglionic inhibitory activity of NE was observed at each dose level of rubidium. Administration of doxepin (25 mcg/kg) immediately after rubidium (0.075 mEq/kg) significantly reduced the inhibitory effect of the cation on NE activity. These results suggest that, in the cat superior cervical ganglion, lithium may block NE uptake and rubidium may promote NE release.

Storage and release of acetylcholine in a sympathetic ganglion.

1. The hypotheses of preferential release of newly synthesized acetylcholine (ACh) and two compartment storage of transmitter in the cat superior cervical ganglion have been re-examined by testing, first, the assumption that ganglionic ACh stores do not alter during a 20 min rest following 60 min preganglionic nerve stimulation at 20/s, and secondly, the implication that the rate of ACh release should be high near the onset of activity and decline to a lower rate with time irrespective of the frequency of stimulation.2. The ganglionic ACh stores were found to increase by 38 +/- 8% within 20 min following 60 min preganglionic nerve stimulation at 20/s, and this extra ACh was releasable.3. The rate of ACh release from ganglia perfused with cat plasma and stimulated at 4/s increased over the first 5 min of stimulation to reach a 27% higher rate that was maintained.4. Correction of the original data to allow for the post-activation increase in ACh stores suggests that newly synthesized ACh equilibrates with most of the preformed stores. The time course of ACh release at 4/s does not support the two compartment model as currently formulated.5. These findings resolve in part a conflict between the physiological data and a recent hypothesis for ACh storage based on ganglion morphology.

Absence of adenine nucleotide release from autonomic ganglion.

SYNAPTIC vesicles isolated from Torpedo electroplaques contain ATP as well as acetylcholine (ACh)1,2. Silinsky and Hubbard3 showed that ATP is released from the rat hemidiaphragm bathed in a hyperosmotic medium and they suggested that the motor nerve terminal releases ACh and ATP simultaneously. Here we report tests for the release of ATP and ACh from the cat superior cervical ganglion; we demonstrated that ACh, but not ATP, is released during stimulation.

Synaptic vesicle depletion and recovery in cat sympathetic ganglia electrically stimulated in vivo. Evidence for transmitter secretion by exocytosis.

This study examined the ultrastructure of presynaptic terminals after short periods of vigorous acetylcholine (ACh) secretion in the cat superior cervical ganglion in vivo. Experimental trunks of cats anesthetized with chloralose-urethane were stimulated supra-maximally for periods of 15-30 min and at several frequencies including the upper physiological range (5-10 Hz). Stimulated and contralateral control ganglia from each animal were fixed by intra-arterial aldehyde perfusion, processed simultaneously, and compared by electron microscopy. Stimulation produced an absolute decrease in the number of synaptic vesicles, an enlargement of axonal surface membrane, and distinct alterations in the shape of presynaptic terminals. Virtually complete recovery occurred within 1 h after stimulation at 10 Hz for 30 min. These results support the hypothesis that ACh release at mammalian axodendritic synapses occurs by exocytosis of synaptic vesicles resulting in the incorporation of vesicle membrane into the presynaptic membrane and that synaptic vesicles subsequently are reformed from plasma membrane.

The effects of various "nicotine-like" agents in the cat superior cervical ganglion in situ.

The effects of nicotine, lobeline, anabasine, cytisine, coniine, sparteine, piperidine, acetylcholine, tetramethylammonium (TMA) and dexamphet-amine, given as i.a. bolus injections, were studied in the cat superior cervical ganglion (SCG) in situ and compared with those of (DMPP) 1,1-dimethyl-4-phenylpiperazinium described in a preceding paper. Two main events are thought to determine the ganglionic response to these agents. A non-selective conductance increase of the ganglion cells by stimulation of nicotinic receptors is responsible for depolarization, firing, facilitation of ganglionic transmission and depolarization block. The accumulation of Na+ resulting from the altered conductance activates an electrogenic Na +-pump which tends to increase the membrane potential and causes a delayed unspecific depression of ganglionic excitability. After agents with a brief agonistic action (acetylcholine, DMPP, TMA), the two mechanisms lead to a distinct biphasic effect on ganglionic polarity (initial depolarization, later hyperpolarization) and transmission (early and later block); with the nicotinic agonists of long duration of action the effect of the electrogenic Na+-pump was obscured by the long-lasting activation of nicotinic receptors and was usually revealed only by special pharmacological procedures. An additional preganglionic depression of transmitter release is very likely. A desensitization of nicotinic receptors occurred after high single or repeated doses of nicotine, resulting in a selective unsurmountable block. A competitive block of nicotinic receptors occurred after coniine. Local anaesthetic properties of lobeline and dexamphetamine interfered with the two main events when high doses were given. The only effect of sparteine was to produce a short-lasting hexamethonium-like block of transmission.

Muscarinic postsynaptic events in the cat superior cervical ganglion in situ.

In the cat superior cervical ganglion in situ volleys in the preganglionic nerve are capable to evoke hyperpolarizing (P-waves) and depolarizing synaptic responses (LN-waves) which are mediated by muscarinic receptors. In the unblocked and unconditioned ganglion a repetitive stimulation by brief trains of shocks is required to produce a LN-wave; a discharge of ganglionic action potentials is only exceptionally seen during this slow synaptic potential. Single shocks evoked no detectable muscarinic effect. After various procedures (tetanic conditioning, anticholinesterases, slight depolarization by nicotinic agents, KCl and isoprenaline), all known to enhance the responsiveness to exogenous muscarinic agents, a ganglionic transmission of impulses through muscarinic receptors was demonstrated both in the presence and absence of an intact nicotinic transmission. The LN-wave is the postsynaptic event mediating the muscarinic pathway. It is best seen during desensitization of nicotinic receptors by high doses of nicotine.

The effects of 5-hydroxytryptamine and some related compounds on the cat superior cervical ganglion in situ.

The effects of 5-hydroxytryptamine (5-HT) and related indole derivatives injected as i.a. bolus injections in a large dose range were studied in the cat superior cervical ganglion (SCG) by recording ganglionic and postganglionic electrical activity. 5-HT had two independent and opposite actions: a long-lasting inhibition of ganglionic transmission occurred already with extremely low doses and increased up to highest ones: both pre-and postsynaptic sites of action seem to be involved. In a medium and high dose range, the inhibitory effect was temporarily masked by a short-lasting stimulation and a depolarisation which was small when compared with that produced by nicotinic agents. The depolarization triggered a secondary hyperpolarization. The stimulant, but not the inhibitory action was very prone to tachyphylaxis.

The effects of l,l-dimethyl-4-phenyl-piperazinium (DMPP) in the cat superior cervical ganglion in situ.

The response of the cat superior cervical ganglion (SCG) in situ to injections of DMPP into its arterial blood supply was investigated by recording continuously both the ganglionic surface (demarcation) potential and the activity in a postganglionic nerve.

A Ganglion Blocking Action of Toxic Substances IS-Toxin and Surugatoxin, from the Japanese Ivory Shell, Babylonia Japonica

Pharmacological properties were studied on IS-toxin (Gohgi et al. 1973 and Hirayama et al. 1970) and Surugatoxin (Kosuge et al. 1972 and Gohgi et al. 1973: S-toxin) isolated from the Japanese ivory shell, Babylonia japonica. The suppression of spontaneous motility. mydriasis and relaxation of the nictitating membrane were induced by these toxins (i.p.) in cats. The effects of S-toxin on the inner plexus of rat and guinea pig small intestine were investigated in vitro. S-toxin reduced or eliminated the contractile responses of this intestine to DMPP or nicotine, but the toxin did not affect the contraction due to McN-A-343. When S-toxin was applied to cat superior cervical ganglion, it reduced or abolished the contractile response of the nictitating membrane induced by DMPP, while the contraction due to McN-A-343 was hardly affected by this toxin. Furthermore. the toxin (applied to the ganglion) inhibited the postganglionic potentials due to stimulation of the preganglionic fiber. These data indicate that S-toxin acts as a specific inhibitor on the nicotinic receptors of the autonomic ganglia. The ganglioplegic action of S-toxin was less potent (about 1/30) than IS-toxin.

The accumulation of hemicholinium by tissues that transport choline.

Cat superior cervical ganglia accumulated 14C-hemicholinium (HC-3), but the amount of drug taken up was not changed by nerve stimulation; accumulated HC-3 was not released by subsequent nerve stimulation. Choline and HC-3 were accumulated by a crude preparation of synaptosomes; the uptake of choline was blocked by HC-3, but the uptake of HC-3 was not blocked by choline. Choline, but not HC-3, was transported by red blood cells. It is concluded that HC-3 is not transported by the choline transport mechanism, and that in concentrations that are usually used in pharmacological experiments, HC-3 appears not to act as, or to form, a false cholinergic transmitter.

The accumulation of radioactive acetylcholine by a sympathetic ganglion and by brain: failure to label endogenous stores.

Abstract— The accumulation of radioactively labelled acetylcholine (ACh) by perfused superior cervical ganglia of cats and by incubated brain slices from rats was studied in the presence of diisopropylphosphorofluoridate. Ganglia accumulated more labelled ACh than an extracellular marker (inulin), but the amount of ACh accumulated did not increase when ACh turnover was increased by preganglionic nerve stimulation. The ACh that accumulated in ganglia was not released when the preganglionic nerve was subsequently stimulated. Sliced cerebral cortex also accumulated labelled ACh but this was not released when the tissue was subsequently exposed to a high K+ medium. Thus accumulated ACh does not appear to mix with releasable transmitter stores. Chronically (7 days) decentralized ganglia lost most of their transmitter store but retained their ability to accumulate labelled ACh. Uptake of ACh by sliced cerebellum was not less than uptake of ACh by sliced cerebral cortex and the amount of ACh accumulated by synaptosomes isolated from cerebellum was similar to the amount of ACh accumulated by synaptosomes isolated from cerebral cortex. It is concluded that ACh uptake is not specifically into cholinergic nerve endings. Hexamethonium reduced ACh uptake by cerebral cortex slices but did not increase the amount of ACh collected from slices stimulated by raised K+.

Potentiation of monoaminergic activity in peripheral ganglia by tricyclic antidepressants

Modification of neuromodulator activity by tricyclic antidepressants was evaluated on the basis of changes in transmission in the cat superior cervical ganglion. Intra-arterial doses of 30 μg of desipramine, 90 μg of protriptyline and 120 μg of nortriptyline were equipotent in facilitating the ganglionic depressive action of epinephrine. At these doses, the ganglionic inhibitory effect of norepinephrine was potentiated to a greater extent by protriptyline than by desipramine and nortriptyline; depression of postganglionic potentials by 5-hydroxytryptamine was augmented by desipramine and protriptyline, whereas dopamine was potentiated only by protriptyline. Propranolol, 200 μg, intra-arterially, enhanced the ganglionic suppressive effect of epinephrine but not norepinephrine. Simultaneous administration of propranolol, 200 μg, and desipramine, 30 μg, potentiated the action of epinephrine to a greater extent than either agent alone.

Detection, determination, and metabolism in vitro of gangliosides in mammalian sympathetic ganglia.

Abstract— Sympathetic ganglia of the rat and cat were examined for the occurrence and distribution of gangliosides. Each rat superior cervical ganglion contained 0.3 nmol of ganglioside‐sialic acid. Extracts of cat superior cervical and nodose ganglia were chromatographed on silica gel thin‐layer plates. The resulting patterns suggested that similar distributions of multiple forms of gangliosides occur in these two tissues, with the fast‐moving gangliosides predominating. The metabolic activity of gangliosides was also investigated in rat superior cervical ganglia in vitro. Evidence was obtained that 14C from [U‐14C]glucose, [U‐14C]pyruvate, and [U‐14C]glucosamine was incorporated into the gangliosides.

Pharmacological studies on the hypogastric ganglion of the rat and guinea-pig.

1. Preparations were developed whereby the hypogastric ganglion of the rat or guinea-pig was perfused through its vasculature with saline solutions. Drugs were injected into the perfusion stream, and their effects were indicated by contractions of the vas deferens. The base of this organ could be ligated to prevent the drugs reaching the smooth muscle via the blood vessels. For comparison, experiments were also performed on fully isolated preparations of the rat and guinea-pig hypogastric nerve-vas deferens, where the vas deferens was held in an inner bath, so that drugs added to the outer bath could act only on the ganglion. Attempts were made to demonstrate non-nicotinic receptors in these preparations.2. It was shown that the perfused hypogastric ganglion of the guinea-pig would respond repeatedly to several nicotinic stimulants, though autodesensitization eventually occurred. The fully isolated preparation behaved similarly, but desensitized much more rapidly. In contrast, the rat ganglion, either perfused or fully isolated, was remarkably insensitive to nicotinic stimulant drugs.3. Neither species responded well to non-nicotinic stimulants; that from the guinea-pig gave small contractions to methacholine in about 33% of cases, but did not respond to (4-m-chlorophenyl-carbamoyloxy)-2-butynyl trimethylammonium chloride (McN-A-343). With the rat, the situation was opposite.4. The guinea-pig ganglion did not become more sensitive to non-nicotinic stimulants after some treatments known to sensitize the cat superior cervical ganglion. These include preganglionic tetanization, chronic decentralization, and removal of all potassium. Sensitization did occur, however, in the presence of physostigmine, after tachyphylaxis to dimethyl phenyl piperazinium iodide (DMPP) had developed, and when the preparation was perfused with a suspension of washed erythrocytes.5. It is concluded that the responses of sympathetic ganglia vary from one species to another, and according to whether the organs are perfused or fully isolated.

The ganglion blocking activity of diastereoisomeric dimethylaminobornyl acetates and their methiodides

Abstract Some diastereoisomeric dimethylaminobornyl acetates and their methiodides have been prepared and tested for ganglion blocking activity. Included in these compounds was an enantiomeric pair and associated quaternary salts. These optical antipodes displayed virtually no difference between their actions at the ganglion. Differences between the activities of the least and most potent diastereoisomers was limited to a factor of about five. Assays were made upon the cat superior cervical ganglion and also the guinea-pig vas deferens preparation the successful quantitative use of which is described.

Rates of transmitter turnover in the cat superior cervical ganglion estimated by electrophysiological techniques.

Rates of transmitter turnover in the cat superior cervical ganglion estimated by electrophysiological techniques.

Identification of prostaglandins in prevertebral venous blood after preganglionic stimulation of the cat superior cervical ganglion.

1. In four out of seven experiments, prostaglandin-like activity was detected in prevertebral venous blood from the superior cervical ganglion, collected during and after preganglionic nerve stimulation.2. Prostaglandins E(1), E(2), F(2alpha) and a prostaglandin A were identified using solvent partition, column and thin-layer chromatography and bioassay techniques.3. The release of PGF(2alpha) was confirmed by combined gas chromatography-mass spectrometry.

The effect of preganglionic stimulation on the acetylcholine and choline content of a sympathetic ganglion.

Preganglionic stimulation of the cat's superior cervical ganglion at 60/s for 2–8 min reduced the ganglion's acetylcholine (ACh) content by about 30%. With continued stimulation, the ACh stores gradually recovered within 15 min. However, when ganglia were allowed to rest following 4 min of stimulation at 60/s not only was there a rapid restoration of the ACh content, but the ACh levels rose to 130% of control after 10 min of rest. Under either of these experimental conditions the choline content increased transiently only after the ACh stores had returned to control values. The above data suggest that there may be a delay in the onset of maximal rates of ACh resynthesis induced by nerve stimulation and that ACh synthesis continues for several minutes after the cessation of the stimulus. In addition, the results are consistent with the concept that about one-third or more of the total ACh stores of a rested ganglion is in a form that can be readily mobilized for release. The observed rebound increase in the ACh content probably means that the ACh storage capacity is not normally saturable and that under most physiological conditions the ACh levels are maintained within certain limits by a precise control of ACh synthesis.

The synthesis, turnover and release of surplus acetylcholine in a sympathetic ganglion.

1. Surplus acetylcholine (ACh) is the extra ACh that accumulates in cholinergic nerve endings when they are exposed to an anticholinesterase agent. The synthesis and turnover of this ACh was examined in the cat's superior cervical ganglion.2. Surplus ACh did not accumulate in chronically decentralized ganglia perfused with eserine-choline-Locke solution, and this shows that it is stored in presynaptic nerve terminals.3. Surplus ACh accumulated more rapidly in ganglia perfused with eserine than in ganglia perfused with neostigmine or with ambenonium; accumulation was delayed by 45-60 min when a quaternary anticholinesterase was used. However, the release of ACh upon preganglionic nerve stimulation was the same during perfusion with eserine, neostigmine or ambenonium. It is concluded that intracellular acetylcholinesterase normally destroys surplus ACh, whereas extracellular enzyme destroys released ACh.4. When ganglia were perfused with [(3)H]choline and eserine, the surplus ACh that accumulated was labelled but its specific radioactivity was only 38% of that of the choline added to the perfusion fluid.5. Surplus ACh was not released by nerve stimulation and was not mobilized for release during, or after, prolonged nerve stimulation. It is concluded that ACh released by nerve impulses is replaced by synthesis at the site of ACh storage and not by movement of ACh from the surplus pool.6. The accumulation of surplus ACh no more than doubled the total ACh content of ganglia, but turnover of ACh continued when the total amount was constant. Surplus ACh may contribute to spontaneous ACh output from eserinized preparations.7. When ganglia were perfused with a medium containing high K(+) (56 mM), surplus ACh was released.