Cervical Sympathetic Stimulation Research Articles

Effects of sympathetic nerve stimulation on intra-oral mechanoreceptor activity in the cat.

1. Micro-electrode recordings were made from intra-oral mechanoreceptor neurones in the trigeminal ganglion and mesencephalic nucleus of the fifth nerve in the cat.2. The effect of cervical sympathetic trunk stimulation on the discharge of the mechanoreceptors to a controlled force was observed.3. Almost half of the mechanoreceptor neurones studied were modulated by sympathetic stimulation. Sympathetic stimulation both decreased the impulse frequency to a controlled force application and raised the threshold in these receptors. The remainder were unaffected by sympathetic stimulation.4. In previous studies involving recordings from either the trigeminal ganglion or mesencephalic nucleus no spontaneously active slowly adapting intra-oral mechanoreceptors have been observed, yet in peripheral alveolar nerve studies many workers have reported spontaneously discharging neurones. In the present study spontaneous activity has been recorded from intra-oral mechanoreceptors both in the trigeminal ganglion and in the mesencephalic nucleus after cutting the cervical sympathetic trunk. The spontaneous activity could be abolished in all cases but one, by sympathetic stimulation. It is suggested that reported spontaneous activity from intra-oral mechanoreceptors could be due to cutting the peripheral nerve and therefore the sympathetic supply, thus removing an inhibitory influence from the sensory unit. The means by which the sympathetic supply inhibits the sensory unit has not been resolved.

Dopamine β-hydroxylase activity in the aqueous humour: effects of cervical sympathetic stimulation and reserpine

Dopamine β-hydroxylase activity has been measured in the aqueous humour, iris and ciliary body of the cat eye under basal conditions and after sympathetic nerve stimulation, and administration of reserpine. Basal dopamine β-hydroxylase activity in 44 eyes was 224±13 pmol/hr/ml for the aqueous humour; for the iris and the ciliary body, it was 136±5 and 41±4 nmol/hr/g, respectively. Cervical sympathetic stimulation elicited a significant rise of aqueous humour dopamine β-hydroxylase activity, whereas no change in tissue dopamine β-hydroxylase activities was observed. Reserpine administration caused a four-fold increase in aqueous humour dopamine β-hydroxylase activity. These results suggest that dopamine β-hydroxylase activity in the aqueous humour may be a useful index of the degree of stimulation of the ocular sympathetic nerves.

Effects of cervical sympathetic stimulation on cerebral and ocular blood flows during hemorrhagic hypotension and moderate hypoxia.

The effect of cervical sympathetic stimulation upon regional blood flows was investigated in albino rabbits during graded hemorrhagic hypotension and mild to moderate hypoxic hypoxia. Regional blood flows were determined using labelled microspheres. Cerebral blood flow (CBF) decreased in response to progressive hypotension and increased considerably during hypoxia (100-200%). Unilateral sympathetic stimulation did not change the ipsilateral cerebral flow responses under either condition. There was a greater tendency to autoregulate down to lower blood pressures in deep than in superficial cerebral structures. During hypoxia cortical gray matter blood flow increased relatively more than did white matter blood flow. Blood flow in different parts of the eye decreased during hypotension and tended to increase during hypoxia. Unilateral sympathetic stimulation reduced flow rates on the stimulated side (10-50% of control side) under both conditions. The vasoconstrictory effect upon retinal blood flow tended, however, to be less during hypoxia. Dural blood flow showed a poor autoregulation and also no consistent vasodilatory response upon hypoxia. Sympathetic stimulation had a very marked effect. The results suggest that the cervical sympathetic nerves do not have any appreciable effect upon cerebral circulation during profound hypotensive and moderate hypoxic states. Dural and most ocular blood flows seem, however, to be clearly affected by sympathetic stimulation even under these extreme conditions.

The effects of sympathetic trunk stimulation on the position and mobility of the canine tooth of the cat

The effects of cervical sympathetic trunk stimulation on the position of the maxillary canine tooth and its movements in response to mechanical loading were studied using an ultrasonic transit time technique. Stimulation of the ipsilateral sympathetic trunk for 10–60s and frequencies between 1 and 20 Hz caused both longitudinal and transverse movements of the tooth. Bilateral carotid occlusion caused negligible movements in either direction. When a controlled force was applied in the palatal direction, sympathetic stimulation caused a labial shift of the tip of the tooth and usually an increase in the load-induced palatal displacement; i.e. the mobility of the tooth was increased and appeared to be dependent on the amount of labial shift of the tooth. It is concluded that interference with the vascular component has little, if any, direct effect on the tooth mobility.

Cerebral and ocular blood flow during alpha 2-blockade: evidence for a modulated sympathetic response.

The effect upon regional blood flows of alpha 2-blockade by yohimbine was investigated in albino rabbits before and during unilateral cervical sympathetic stimulation. The combined effects of i.v. angiotensin, alpha 2-blockade and sympathetic stimulation were also investigated. Regional blood flows were determined using the labelled microsphere method. Yohimbine produced high flow rates in the eyes, the dura, the choroid plexus and in the peripheral organs. Sympathetic stimulation during alpha 2-blockade caused significant blood flow reductions in the brain, the eye and in all other tissues investigated. In the brain the flow reduction was 20-25% in several structures. Angiotensin caused marked reductions in blood flow in the dura and in most peripheral tissues. The effects of sympathetic stimulation were not appreciably changed. The results suggest that vascular alpha 2-receptors affect the vascular tone in some organs and that presynaptic alpha 2-receptors modulate the response to sympathetic stimulation in the brain, the optic nerve and in the choroid plexus.

Pial venous constriction during cervical sympathetic stimulation in the cat

Acta Physiologica ScandinavicaVolume 110, Issue 2 p. 203-205 Pial venous constriction during cervical sympathetic stimulation in the cat LUDWIG M. AUER, LUDWIG M. AUER University Clinic of Neurosurgery, Graz, Austria and Department of Neurology, University of Göteborg, SwedenSearch for more papers by this authorBARBRO B. JOHANSSON, BARBRO B. JOHANSSON University Clinic of Neurosurgery, Graz, Austria and Department of Neurology, University of Göteborg, SwedenSearch for more papers by this author LUDWIG M. AUER, LUDWIG M. AUER University Clinic of Neurosurgery, Graz, Austria and Department of Neurology, University of Göteborg, SwedenSearch for more papers by this authorBARBRO B. JOHANSSON, BARBRO B. JOHANSSON University Clinic of Neurosurgery, Graz, Austria and Department of Neurology, University of Göteborg, SwedenSearch for more papers by this author First published: October 1980 https://doi.org/10.1111/j.1748-1716.1980.tb06652.xCitations: 15AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume110, Issue2October 1980Pages 203-205 RelatedInformation

Early effects of cervical sympathetic stimulation on cerebral, ocular and cochlear blood flow.

Autoregulatory mechanisms may be expected to modify effects of vasomotor nerve stimulation in many tissues. Attempts were made to reveal a distinct early, but transient effect of cervical sympathetic stimulation on cerebral, retinal and cochlear blood flow. The labelled microsphere method was used to determine regional blood flow during electrical stimulation of the cervical sympathetic chain for 15-25 s and 5 min. At a frequency of 6 Hz there was 5% reduction in cerebral flow at 15-25 s and 7% at 5 min. In the choroid plexus the mean reduction was 22% at 15-25 s but decreased 10% after 5 min. In the cerebellum, optic nerve and retina, sympathetic stimulation had no appreciable effect on the blood flow. In the cochlea and iris, the blood flow reductions were 25 and 32%, respectively, on both occasions. In the choroid, vasoconstriction increased with time, whereas in the masseter muscle there was a decrease. Thus in the present experiments no indication was found of an autoregulatory escape phenomenon in the brain, the eye or the cochlea. Some escape was noted in the masseter muscle.

Nervous control of blood flow in the dental pulp in dogs.

AbstractPulpal blood flow (PBF) was measured by H2‐gas clearance in 30 dogs during electrical nerve stimulation, denervation and close intraarterial infusion of noradrenaline (NA). Electrical stimulation of the cervical sympathetic nerve and NA infusion always resulted in decreased PBF. The constrictor effect was reduced by α‐blockers, but was never abolished or reversed to a vasodilation. Thus, no evidence for β‐receptors in the dental pulp blood vessels was found. The fall in PBF produced by cervical sympathetic stimulation could be prevented by cutting the inferior alveolar nerve in the mandibular canal. Stimulation of the cut inferior alveolar nerve in the mandibular canal produced variable pulpal flow changes: Both a marked increase and decrease were measured. The flow changes during inferior nerve stimulation were unaffected by α‐receptor blockade, while atropine reduced the vasoconstrictor respons or augmented the dilatory response. Electrical stimulation of the mandibular nerve before its entrance in the canal caused vasodilation, proposing a sensory antidromic axonreflex in the dental pulp. Sympathetic denervation had little or no effect on PBF, while cutting of the inferior alveolar nerve in the canal increased PBF in lower canine from 0.159 to 0.219 ml/min. g. The experiments show that pulp blood vessels of the dog may be controlled by both vasodilator and vasoconstrictor nerve fibers.

Cochlear blood circulation studied with microspheres.

The cochlear blood flow was studied with the microsphere method in guinea pigs, rats and cats. Results from experiments using different sizes of microspheres were compared and the effect of middle ear infection or perforation of the otic capsule on the cochlear microcirculation was investigated. Neither the opening of the cochlear bony wall nor the middle ear infection influenced the blood flow in the cochlea. 9- and 15-micrometer spheres were given simultaneously and the results were equivalent, indicating no more shunting of the smaller ones than of the bigger ones. Thus, the smaller spheres are to be preferred, since the smaller ones can be used in a larger number without negative effects on the general circulation. In cats, the cochlear blood circulation was determined before and during cervical sympathetic stimulation. Sympathetic stimulation caused a reduction of 25% of the cochlear blood flow.

Bilateral nasal vascular responses to unilateral sympathetic stimulation.

Unilateral preganglionic cervical sympathetic stimulation in the anaesthetized cat evoked vasoconstriction in both nasal cavities, dependent on stimulation frequency. Vasoconstriction in the contralateral cavity was 15--20% of that of the stimulated side. Similar findings were obtained on unilateral Vidian nerve stimulation. Vasoconstriction evoked in the sympathectomized nasal cavity by stimulating the opposite cervical chain was reduced but not abolished by sectioning the posterior nasal and ethmoidal nerves of the stimulated side. It is suggested that vasoconstrictor fibres reach the opposite cavity either in these nerves or by way of blood vessels, but more likely that sympathetic fibres from these pathways innervate blood vessels which supply both nasal cavities.

Quantitative multiregional blood flow measurements during cervical sympathetic stimulation

The ethanol tissue sampling method for rCBF measurement was used to obtain information on the effects of cervical sympathetic stimulation in 8 cerebral structures in the non-anaesthetized rabbit. Sympathetic stimulation induced flow decreases of 12-29% according to structure, confirming the capability of this nerve to significantly reduce rCBF. Furthermore, a regional differentiation of cerebral structures into an 'anterior' group (mean decrease 22%) and a 'posterior' group (mean decrease 12%) with different reactivity to stimulation was established, thus confirming previous work in this laboratory with a local thermoclearance technique, and histochemical studies on sympathetic innervation to cerebral arteries and arterioles. These results provide strong evidence of the functional nature of the sympathetic nervous system in CBF regulation. The complementary nature of the ethanol technique (quantitative, multiregional measurement) and the local thermoclearance technique (continuous, semiquantitative measurements in 2-3 regions), and the absence of anaesthesia and significant trauma, means that combination of these two techniques offers considerable advantages in research on dynamic phenomena of the kind studied here.

Effects of cervical sympathetic stimulation on carotid occlusion reflexes in cats.

Effects of cervical sympathetic stimulation on carotid occlusion reflexes in cats.

Vago-sympathetic modulation of gastric mechanoreceptors: effect of distention and nutritional state.

Unit discharge evoked in gastric afferents by tactile stimulation of the frog's stomach was inhibited by electrical stimulation of gastric vagi and facilitated by cervical sympathetic stimulation. The inhibition or the facilitation of the evoked response depended on the mode and parameters of stimulation used. The tactually-evoked activity was also inhibited by gastric distention in well-fed animals (Type-I). This inhibition was released by gastric vagotomy, while cervical sympathectomy had no appreciable effect on the evoked inhibitory response.

Decrease in cerebrospinal fluid-pressure induced by cervical sympathetic stimulation

Summary In cats monolateral and bilateral stimulation of the cervical sympathetic trunks causes a reduction of the cerebrospinal fluid-pressure, the responses being evident also within the range of physiological frequencies. Neither cocaine nor guanethidine and nicergoline, an alpha-receptor blocking agent, influenced the responses to nerve stimulation at doses which per se did not markedly change CSF-pressure or systemic blood pressure.

Study of the hypotensive action of berbamine, an alkaloid isolated from berberis lycium

The hypotensive action of barbamine, an alkaloid isolated from Berberis lycium, has been investigated. Cats anaesthetized with nembutal were used for recording changes in blood pressure and force of cardiac contraction. Preparations of rat hindquarter, isolated guinea pig ileum and isolated perfused rabbit heart were also put up to see the local effects of berbamine. Berbamine in 5 and 10 mg/kg doses produced a significant decrease in the mean arterial blood pressure and the amplitude of cardiac contractions. The hypotensive effect was significantly anatagonized by dimetane maleate. These doses did not alter the contractile responses of nicititating membrane to pre ganglionic cervical sympathetic trunk stimulation and their hypotensive response were not modified by atropinization or bilateral vagotomy. In cross circulation experiments berbamine in 10 mg/kg doses when injected into the common carotid artery of the recipient cats produced hypotension only in the donor cats. Doses ranging from 0.125 to 1 mg of berbamine significantly reduced the amplitude of contractions of the isolated rabbit heart. The perfusate collected from the rat hindquarter preparations after injection of 5 mg doses of berbamine produced a marked contraction of the isolated guinea pig ileum preparation which was antagonized by dimetane maleate. On the basis of these observations it is suggested that berbamine produces its hypotensive effects due to its direct depressant action on the myocardium and release of histamine from the tissues.

The effects of certain drugs, cervical sympathetic stimulation and section on nasal patency.

The effects of certain drugs, cervical sympathetic stimulation and section on nasal patency.

Effect of cervical sympathetic stimulation on accommodation in monkeys. An example of a beta-adrenergic, inhibitory effect.

AbstractThe preganglionic cervical sympathetic nerve, of mainly cynomolgus monkeys (Macaca irus), has been stimulated electrically using different stimulation rates. The accommodative response to stimulation was a change in refraction towards hypermetropia. This response could not be inhibited by adrenergic α‐receptor antagonists, though these drugs reduced the blood volume changes in the eye upon stimulation. On the other hand, the β‐adrenergic blocker propranolol caused a complete elimination of the sympathetic stimulation response, though changes in eye volume seemed uninfluenced. The accommodative response (in diopters) to stimulation increased considerably when the eye was under strong cholinergic tone. When the animal was pretreated with a large dose of atropine. cervical sympathetic stimulation did not affect the refractive state of eye. The results indicate the presence of a β‐adrenergic, inhibitory mechanism of the ciliary muscle. Possibly this mechanism is responsible for distance accommodation (decrease in accommodation). Changes in vascular structures upon sympathetic stimulation play no practical part in regulating the accommodation.

Cerebral sympathetic vasoconstriction and EEG.

Summary. 1 The influence of electrical stimulation of the cervical sympathetic nerves and the thoracic sympathetic chain as well as the central and peripheral parts of the cat vagi upon the cortical blood flow and the EEG has been investigated in unanesthetized (encephale isole) and lightly anaesthetized cats, sensitive to arousing stimuli. 2 It has been confirmed that stimulation of the cervical sympathetic nerves gives a cerebral vasoconstriction which, according to the method used, may reduce the blood flow by 10–20%. In lightly anaesthetized preparations section of the same nerves gave a significant reduction of the cerebral vascular resistance (increase of flow of up to 25 %). Stimulation of the thoracic sympathetic chain did not give rise to a more pronounced cortical vasoconstriction than did cervical stimulation. 3 In preparations with intact sinus nerves cervical sympathetic stimulation was accompanied by a slight decrease of blood pressure (Palme 1943). Blood pressure alterations were less pronounced after section of the sinus nerves. Vagal stimulation gave a decrease of the blood pressure and a proportional decrease of the cortical blood flow. 4 In the large majority of cases, maximal sympathetic vasoconstriction was not followed by any change of the EEG. Some observations indicate, however, that when the cerebral blood flow was critically low, a small further decrease due to sympathetic vasoconstriction influenced the EEG. 5 The sympathetic vasomotor innervation of cerebral vessels probably plays a subordinate role for the circulatory adjustments in the brain during changes in its state of excitability.

Cervical Sympathetic Stimulation Caused by Carcinoma of the Lung

There are described two patients with carcinoma of the apex of the lung who exhibited the effects of stimulation of the cervical sympathetic nervous system; namely, widening of the palpebral fissure, dilatation of the pupil, increased sweating on the same side of the face and the upper extremity of the same side. The findings are exactly opposite those found in Horner's syndrome.

Psychophysiological factors in Ménière's disease.

Summary Psychiatric study of 23 patients with Ménière's disease demonstrates that the paroxysmal attacks of vertigo and often the onset of tinnitus and deafness can definitely be related to life stress situations. There is apparently a fundamental emotional predisposition but the first acute attack of vertigo, as well as most subsequent attacks, tends to follow an explosive outburst or a damming-up of tension in an underlying intolerable situation. The red blood cell flow as observed with the high powers of a slit lamp in the conjunctival vessels of these patients before and especially immediately after these attacks resembles that seen in cats subjected to intravenous epinephrin or cervical sympathetic stimulation. This has been observed in most of the patients and experimentally produced by psychic stimulation in 2. There is slowing of the circulation with lumping of blood such as has been called "blood sludge." Occasionally there are microscopic hemorrhages. The conclusion is that the clumps of blood stick in the tiny vessels of the labyrinth where they produce local disturbances which in turn produce symptoms and eventually, if the vascular pathology persists, the picture of labyrinthine hydrops characteristic of advanced Ménière's disease.