Effects Of Superior Cervical Ganglionectomy Research Articles

Cervical sympathectomy causes alveolar bone loss in an experimental rat model

Periodontal disease, a pathological destructive inflammatory condition, is characterized by alveolar bone loss. Recent studies have suggested a correlation between the sympathetic nervous system and bone remodeling. To confirm the importance of the sympathetic nervous system in bone resorption, we investigated the effects of superior cervical ganglionectomy and oral challenge with Porphyromonas gingivalis on alveolar bone loss in rats. Rats were divided into three groups: group A underwent a sham operation as the control group; group B underwent superior cervical ganglionectomy; and group C underwent a sham operation and oral challenge with P. gingivalis. Horizontal alveolar bone loss was evaluated by measuring the distance between the cemento-enamel junction and the alveolar bone crest. Cytokine gene expression in the gingival tissues was assessed using reverse transcription-polymerase chain reaction analyses. The furcation areas of the mandibular molars were examined histologically. Both superior cervical ganglionectomy and oral challenge with P. gingivalis resulted in accelerated alveolar bone loss. Gingival tissues in the superior cervical ganglionectomy group showed increased expression of the cytokines interleukin-1 alpha, tumor necrosis factor-alpha and interleukin-6. The density of neuropeptide Y-immunoreactive fibers was decreased following superior cervical ganglionectomy. Osteoclasts were observed in the superior cervical ganglionectomy and P. gingivalis-challenged groups. Both superior cervical ganglionectomy and oral challenge with P. gingivalis induced alveolar bone loss. These results provide new information on the occurrence of alveolar bone loss, in that both oral challenge with P. gingivalis and superior cervical ganglionectomy are important accelerating factors for alveolar bone loss. Thus, we suggest that the sympathetic nervous system is linked with the prevention of alveolar bone loss.

Effects of superior cervical ganglionectomy on body temperature and on the lipopolysaccharide-induced febrile response in rats

The involvement of the cervical sympathetic ganglia (SCG) on body temperature and during the occurrence of the induced febrile response was investigated in rats. Bilateral superior cervical gaglionectomy (SCGx) attenuated the daily dark-phase temperature compared to that of the sham-operated rats during the first 2 days post surgery. Body temperatures returned to pre-surgery levels by Day-3. Ten days after surgery, a febrile response was induced by lipopolysaccharide (LPS) immune challenge. SCGx significantly blunted the LPS-induced febrile response. These data suggest that obliteration of the cervical sympathetic peripheral innervation impairs the capability to produce an induced febrile response.

The effects of superior cervical ganglionectomy on the anxiety in the rats.

Therapeutic indications for stellate ganglion block range from head and upper arm disease to general disease including psychosomatic disorders. The aim of this study was to evaluate the effects of superior cervical ganglionectomy on anxiety using the elevated plus maze test. Male Sprague-Dawley rats (150-250 g) were used. Each rat was put into the elevated plus maze 5 minutes per day for 10 days. We checked the number of entries into each arm (open arm and closed arm) and the duration of time staying in each arm. Rats were then divided into two groups: a group that received bilateral superior cervical ganglionectomy, and a control group that received a sham operation. The elevated plus maze test was then repeated and we evaluated the effect of superior cervical ganglionectomy on anxiety. Although there was an increased tendency of ganglionectomized rats to enter each arm, there were no significant differences in number of entries or in duration of stay between experimental and control groups. Bilateral superior cervical ganglionectomy in rats does not reduce anxiety. However, further studies are needed, ones combined with neuroendocrine and clinical studies, to determine the effect of superior cervical ganglionectomy on behavioral responses.

The Effects of Superior Cervical Ganglionectomy on C-fos Expression in Rat Brain

Background: C-fos is a marker of neuronal activity and its expression may be related to various types of stimulation of primary sensory neurons. We evaluated the effect of superior cervical ganglionectomy on c-fos expression in rat brain, which was expected to have the same effect as stellate ganglion block in human. Methods: Male Sprague-Dawley rats (140-150 g) were divided into 4 groups; a no treatment (control group, n = 10), a 2 hour enflurane inhalation (anesthesia group, n = 10), a cervical skin incision only group (sham group, n = 10) and a superior cervical ganglionectomy group (sympathectomy group, n = 10). Two hours after each procedure, rats were killed and perfused with formaldehyde solution. c-fos protein expressions in the thalamus, hypothalamus, cortex, amygdala and cingulate gyrus were examined by immunohistochemistry using a specific antibody. Results: In the thalamus, c-fos expression increased in the sympathectomy group vs. the control and the anesthesia groups, and in the sham group vs. the control group. In amygdala, the sham group showed significantly higher c-fos expression than the control group. In the hypothalamus and cortex no significant differences among the 4 groups were apparent. In the cingulate gyrus higher c-fos expression was observed than the control and anesthesia group but no differences with sham group. Conclusions: Superior cervical ganglionectomy itself may not affect c-fos expression in rat brain. For best results special effort should be made to avoid surgical or emotional stress.

Time dependent effects of sympathetic denervation on aqueous humor dynamics and choroidal blood flow in rabbits

Purpose. This study investigates the time-dependent effects of superior cervical ganglionectomy (SCGx) on aqueous humor dynamics and ocular blood flow in rabbits. Methods. Measurements were made at various times between 24 hours and 12 months after SCGx. Intraocular pressure (IOP) was measured by pneumatonometry, aqueous flow by fluorophotometry and outflow facility by tonography. Uveoscleral outflow was determined by an intracameral tracer infusion technique and blood flow to the choroid was evaluated with fluorescent microspheres. Values in denervated eyes were compared with the contralateral, normallyinnervated eyes using a paired Student's two-tailed t-test. Results. At 24 hours after SCGx, IOP in denervated eyes was less than in normally-innervated eyes (14.6 ± 0.8 vs 20.1 ± 1.5mmHg, 27%, p < 0.002). At one month, IOPs were not different between eyes. Compared with normally-innervated eyes at 10-12 months, IOP in denervated eyes was greater (20.4 ± 0.7 vs 17.2 ± 0.9mmHg, 19%, p < 0.001), outflow facility was less (0.15 ± 0.02 vs 0.21 ± 0.01µl/min/mmHg, 29%, p < 0.01) and blood flow to the choroid was less (12.1 ± 5.0 vs 16.2 ± 6.0 ml/min/gm tissue, 25%, p < 0.05). Aqueous humor flow was not significantly altered by SCGx at any time. Conclusions. The reduction in IOP at 24 hours after SCGx was not due to any change in aqueous flow or uveoscleral outflow (current study) but rather to an increase in outflow facility (previous studies). At 10-12 months, IOP was elevated because outflow facility was significantly reduced. The reduction in choroidal blood flow at 10-12 months may have occurred because of the increased IOP.

Changes in substance P content at the hypothalamic-pituitary axis during the Wallerian degeneration of peripheral sympathetic neurons after superior cervical ganglionectomy in male rats: effect of hyperprolactinemia.

The effects of Wallerian degeneration of the peripheral sympathetic neurons projecting to the hypothalamus on the mechanism of interaction between prolactin and substance P (SP) were examined. The effects of superior cervical ganglionectomy (SCGx) on SP content in various hypothalamic regions and in the hypophysis were evaluated in control and hyperprolactinemic rats. Male rats that received pituitary transplants at the age of 5 days and age-matched sham-operated controls were used. Pituitary grafting significantly increased circulating values of prolactin, as did SCGx. In hyperprolactinemic rats, SCGx partially decreased plasma prolactin levels. Neonatal hyperprolactinemia decreased SP content in the anterior (AH) and posterior (PH) hypothalamus and in the median eminence (ME), but increased it in the mediobasal hypothalamus (MBH). Acute SCGx significantly increased SP in the MBH, PH, and ME. SCGx in hyperprolactinemic animals further increased SP content in MBH. In the ME and Ah, SCGx in pituitary grafted rats decreased SP content as compared with the controls. In the pituitary gland (PG), SCGx only decreased SP content in hyperprolactinemic, but not in control rats. An interaction between peripheral nor-adrenergic neurons and prolactin to regulate SP within the hypothalamus was positive in the MBH, AH, ME, and PG, but not in the PH. These data indicate the existence of interactive mechanisms between prolactin and the peripheral sympathetic neurons to regulate SP content at the hypothalamic-pituitary axis. Interrelationships between prolactin and SP were also observed.

Peptidergic peripheral nervous systems in the mammalian pineal gland

The distribution and density of tyrosine hydroxylase (TH) and neuropeptide Y (NPY)-immunoreactive, sympathetic fibers and calcitonin gene-related peptide (CGRP)-, substance P (SP)-, and vasoactive intestinal polypeptide (VIP)-immunoreactive, non-sympathetic fibers in the pineal gland, the effects of superior cervical ganglionectomy (SCGX) on these fibers, and the location of their terminals in the pineal gland were compared between rodents and non-rodents. A dense network of TH/NPY-positive fibers is present all over the pineal gland. A less dense network of CGRP/SP- or VIP-positive fibers occurs in the whole pineal gland of non-rodents, but these fibers are usually confined to the superficial pineal gland in rodents. After SCGX, some TH/NPY-fibers remain only in the deep pineal gland in rodents, whereas considerable numbers of these fibers persist throughout the gland in non-rodents. Thus, the remaining fibers, probably originating from the brain, may be more numerous in non-rodents. Since CGRP-, SP- or VIP-immunoreactive fibers in the pineal capsule can be traced to those in the gland, and since these fibers are ensheathed by Schwann cells, it is concluded that these fibers belong to the peripheral nervous system. However, the existence of SP-positive central fibers cannot be denied in some species. In the superficial pineal gland of rodents, sympathetic terminals are mostly localized in perivascular spaces, whereas the parenchymal innervation by sympathetic fibers in the pineal gland is more dense in non-rodents than in rodents. Synapses between sympathetic nerve terminals and pinealocytes occur occasionally in non-rodents, but only rarely in the superficial pineal gland of rodents. The occurrence of the synapses may depend on the frequency of intraparenchymal sympathetic terminals.

Acute and Chronic Effects of Superior Cervical Ganglionectomy on in vitro Mitogenic Responses of Lymphocytes from Submaxillary Lymph Nodes of Pituitary-Grafted Rats

Male rats were grafted an anterior pituitary within breast muscles or received a sham operation on day 5 of life. At the 60th day of life, the sympathetic denervation of rat submaxillary lymph nodes was achieved by a bilateral sympathetic superior cervical ganglionectomy (SCGx; at 15.00 h). Rats were killed either 18 h later (acute SCGx) or after 12 days (chronic SCGx) to measure lipopolysaccharide (LPS)- and concanavalin A (ConA)-induced cell proliferation in submaxillary lymph nodes, submaxillary lymph node cellularity and serum prolactin levels. In control rats, acute SCGx significantly augmented LPS or ConA activity on lymph cells while chronic SCGx had no effect. In pituitary-grafted rats, acute SCGx depressed the mitogenic effect of LPS or ConA whereas chronic SCGx augmented it. A global inhibitory effect of surgical stress on submaxillary lymph node cellularity was found in rats subjected to SCGx or its sham operation 18 h earlier. Serum prolactin levels increased significantly in pituitary-grafted rats, particularly in those subjected to chronic SCGx. In pituitary-grafted rats, a significant effect of acute SCGx was apparent, with serum prolactin levels augmenting about twice in sham-SCGx rats, and to a significantly less extent in acute SCGx rats. The results provide further evidence of the immunomodulatory role of local sympathetic nerves in submaxillary lymph nodes.

Effects of Superior Cervical Ganglionectomy and Melatonin Replacement on Intra-hypothalamic LHRH Content and Pulsatile Luteinizing Hormone Release in the Mink

Long-term effects of subcutaneous melatonin implants on intrahypothalamic LHRH content and on pulsatile luteinizing hormone release have been investigated in ganglionectomized male mink. Animals were submitted to bilateral removal of the superior cervical ganglion in mid-April. A preliminary study revealed that plasma LH concentrations remain at a basal level throughout the year following ganglionectomy. In a second experiment, one month after ganglionectomy and transfer from the natural photoperiod environment to short daylengths (LD 4:20), melatonin pellets were subcutaneously implanted to overcome deafferentation of the pineal. Progressive effects of treatment were studied 7 days, 15 days, and one, two and three months after insertion of the melatonin implants. The intra-hypothalamic LHRH content in ganglionectomized mink was at a basal level similar to that observed during seasonally sexual quiescence, or after exposure to inhibitory long days (LD 20:4). A significant and transient elevation in LHRH content was observed already after fifteen days, and also one month after insertion of melatonin implants. This resulted in mean values similar to those observed during the breeding season, or after exposure to stimulatory short days (LD 4:20). A decrease in hypothalamic LHRH content started after two months. No pattern of pulsatile LH secretion was recorded in ganglionectomized untreated mink. A significant increase in all parameters of pulsatile LH secretion was observed fifteen days after the elevation of LHRH content induced by melatonin treatment, and maximum values were reached after two months. Pituitary activity tended to decrease after three months, characterized in particular by a significant decrease in the mean frequency of LH pulses. In addition, the increase in pulsatile characteristics of LH release occurred two months before the peripheral renewal of testicular activity. Apparently, the reproductive endocrine function in ganglionectomized mink treated with melatonin implants is restored more rapidly at the hypothalamic level than at the pituitary or testicular levels.

Behavioural and neurochemical effects of superior cervical ganglionectomy in rats with septo-hippocampal lesions.

This longitudinal study, extending over 12 months, assessed the behavioural and biochemical effects of hippocampal sympathetic ingrowth (HSI) into the partially denervated hippocampus. Male Long-Evans rats received fimbria-fornix lesions (FIFO) or sham operations at 90 days of age. At the same time half of the rats from each group sustained bilateral ablation of the superior cervical ganglia (SCGX). A battery of behavioural tests, measuring spontaneous alternation, activity in the open field and home cage, and radial-maze performance, were employed, starting after one very short (16 days) and one extended (216 days) post-operative delay. Neurochemical analyses measuring choline acetyltransferase (ChAT) activity, high-affinity choline (HACU) and noradrenaline uptake by hippocampal synaptosomes (HANU), hippocampal noradrenaline ([NA]), serotonin ([5-HT]) and 5-hydroxyindoleacetic acid ([5-HIAA]) concentrations were carried out in a dorsal, a "middle" and a ventral region of the hippocampus. Lesion of the FIFO induced a significant and enduring deficit in radial-maze performance, in addition to a persistent locomotor hyperactivity. ChAT and HACU were significantly depleted in all three regions of the hippocampus at 12 months, and these deficits were negatively correlated with maze performance. SCGX in the presence of the FIFO lesion significantly reduced [NA] in the middle region of the hippocampus, as compared to SCGX rats, and contributed to a restoration of lesion-induced depletions in [5-HT] and [5-HIAA] in the middle and ventral hippocampal regions, whilst failing to elicit any behavioural changes at either time point. It is concluded that if lesion-induced HSI indeed occurred, as is suggested by neurochemical evidence, it had no effect upon the observed behavioural deficits elicited by transection of the FIFO in the rat.

Short-day stimulation of testicular activity and immunoreactivity of the hypothalamic GnRH system in mink following deafferentation of the pineal body by bilateral superior cervical ganglionectomy and melatonin replacement

The effects of superior cervical ganglionectomy on testicular function (testis volume and plasma testosterone levels) and the immunocytochemical activity of the GnRH hypothalamic system were studied in the mink, a short-day breeder. Animals reared in a natural photo-period were (i) ganglionectomized at four different times during the period extending from the end of summer to the end of autumn (September 15, October 20, October 28, and December 1), and (ii) reared for 50 days in a short gonadostimulatory photoperiod (4L:20D). Lastly, an attempt was made to overcome the effects of superior cervical ganglion removal by administering melatonin to mink reared in a natural photoperiod. In mink reared in a natural photoperiod, deafferentation of the pineal on September 15 ( L= 12.5h) or October 20 ( L= 10.5h) resulted in consistently low values of testicular volume and plasma testosterone until the end of the experiment (February). When the operation was performed on October 28 ( L= 10h) testicular activity was initiated but only lasted a short time and did not allow maximal gonadal development. When superior cervical ganglionectomy was carried out on December 1 ( L= 8.5h), during the phase of renewed testicular activity, the increases in testicular volume and testosterone levels were not affected by the operation and the subsequent variation of these parameters was identical to that observed in intact animals. Similarly, in mink reared for 50 days in a photoperiod of 4L:20D before superior cervical ganglionectomy, deafferentation of the pineal did not prevent gonadostimulation induced by short days. These results show that once the hypothalamic system secreting GnRH is triggered by short days, its activity is no longer controlled by the photoperiod. The immunohistochemical study of GnRH-secreting hypothalamic neurons, carried out in December without prior colchicine treatment in animals ganglionectomized in September or October, showed the presence of only a small number of GnRH-positive perikarya. Similarly, positive axonal endings in the external layer of the median eminence were scarce and weakly immunoreactive. On the other hand, in intact animals, in those ganglionectomized on December 1, and those exposed to the short photoperiod of 4L:20D, perikarya and immunoreactive endings were numerous and intensely labeled. In mink ganglionectomized in October ( L= 10.5h) and thereby maintained in a phase of sexual quiescence, insertion of melatonin implants in January triggered testicular activity 50 days later.

Inhibitory effects of superior cervical ganglionectomy on dimethylbenz(a)anthracene-induced mammary tumors in the rat.

The role of the pineal in regulating the oncogenic processes was explored in Sprague-Dawley female rats by comparing incidence and growth of mammary tumors in animals subjected to superior cervical ganglionectomy (SCGx) or blinding and anosmia (BAs) with that of intact rats treated with 7-12-dimethylbenz(a)anthracene (DMBA). The surgery was performed at the age of 56 days, 1 day following the administration of the carcinogen. Growth of mammary tumors was studied, and 15 weeks later the rats were sacrificed by decapitation and the activity of the pineal hydroxyindole-O-methyltransferase (HIOMT) was determined. Carcinostatic effects of similar magnitude were present in both SCGx and BAs groups as evident from tendency toward reduced tumor incidence and decreased total tumor mass. Ganglionectomized rats developed significantly smaller numbers of tumors than intact control animals. A trend toward reduced tumor number and increased tumor regression was evident in the BAs group. Although there was no significant difference in tumor volumes among the groups, BAs animals showed a distinct trend toward smaller tumor volumes at the termination of the experiment. Despite similar carcinostatic tendencies, SCGx rats had significantly lower HIOMT activity than BAs animals. The possible existence of multiple carcinostatic mechanisms in BAs and SCGx rats is discussed.

Long-term effects of superior cervical ganglionectomy on cortical blood flow of non-anesthetized rabbits in resting and hypertensive conditions

The long-term effects of sympathectomy on cerebral cortical blood flow (CBF) were studied in the conscious rabbit. The quantitative, repeated measurements of blood flow were made by determination of helium clearance by mass spectrometry and were obtained simultaneously with measurements of local tissue pO 2 and pCO 2. Eight to 10 weeks after unilateral sympathectomy, resting blood flow in the homolateral cortex was decreased by a mean of 17% compared to the heterolateral cortex. In two animals in which blood flow was recorded both before and after the sympathectomy, the same phenomenon was observed from 8 to 30 days after the operation. The response to i.v. infusion of noradrenaline was identical in both hemispheres: doses inducing a 40% rise in blood pressure did not significantly modify CBF. The responses to angiotensin II-induced hypertension were also identical. Histochemical verifications demonstrated the effectiveness of the denervation in the pial arteries and the intraparenchymal arteries in the region studied. Thus the decrease in CBF induced by chronic sympathectomy cannot be attributed to the development of hypersensitivity to catecholamines. This decrease remained stable whatever the value of resting flow and was maintained under anesthesia. It is concluded that, as in the peripheral circulation, chronic sympathectomy affects the equilibrium of the vascular smooth muscle fibers, but that circulating amines play no compensatory role in the cerebral circulation because of the blood-brain barrier.

Sympathetic nerves protect against blood-brain barrier disruption in the spontaneously hypertensive rat.

SUMMARY The cerebral vessels of spontaneously hypertensive rats (SHR) are reported to have an in­ creased luminal size and decreased wall thickness after chronic sympathetic denervation. In order to evaluate a possible physiological significance of this observation, we studied blood-brain barrier protein transfer in two month old SHR and their normotensive controls, Wistar-Kyoto (WKY), during profound vasodilation stimuli one month after a unilateral superior cervical ganglionectomy. Our hypothesis was that during acute vaso­ dilation, protein transfer, which is dependent on vessel tension (tension = pressure X radius/wall thickness), would be greater in the vasculature of the chronically denervated (De) than in contralateral innervated hemi­ sphere (In). Vasodilation was induced with acute hypertension (norepinephrine) and seizures (bicucilline). Immediately prior, the cervical trunk to the innervated hemisphere was sectioned to prevent acute sympathetic neuronal effects. Protein transfer was assessed qualitatively with Evans blue dye and quantitatively with radio­ iodinated albumin. Successful chronic denervation was demonstrated by the absence of histofluorescence in De. Evans blue dye staining of SHR (n = 3) cerebral hemispheres was greater in De than in In. Radioiodinated albumin protein transfer was elevated in SHR De compared to In in each of eight animals studied (De-In = 0.16 ± 0.04%*, *p < 0.01); WKY (n = 8) De protein transfer was not different from In (De-In = 0.07 ± 0.05%). These results suggest that the trophic influence of sympathetic nerves on SHR cerebral vessels con­ tributes to protection of the blood-brain barrier during hypertension and seizures.

Superior cervical ganglionectomy depresses norepinephrine uptake, increases the density of alpha-adrenoceptor sites, and induces supersensitivity to adrenergic drugs in rat medial basal hypothalamus.

The occurrence of nonpineal mediated effects of superior cervical ganglionectomy (SCGx) on neuroendocrine function prompted us to study SCGx effects on medial basal hypothalamic (MBH) norepinephrine (NE) content and uptake, and on MBH α- and β-adrenoceptor sites assessed by ³H-dihydroergocryptine and ³H-dihydroalprenolol binding. SCGx depressed MBH NE uptake but did not affect NE content in MBH homogenates. After SCGx, a significant 35% increase of α-adrenoceptor sites occurred in MBH whereas the β-adrenoceptors remained unchanged. In order to correlate the increase of binding sites with adrenoceptor-mediated supersensitive responses in MBH, the effects on NE, isoprotere-nol or L-dihydroxyphenylalanine (L-dopa) on MBH tubulin concentration were assessed. Each drug brought about a greater depression of MBH tubulin in SCGx than in control rats. A dose-response study of the MBH tubulin decrease after L-dopa treatment indicated that SCGx augmented the potency of L-dopa by 2.5-fold, shifting the dose-response curve to the left in a parallel manner. Such increase in potency was only 1.6-fold when SCGx was associated with Px. SCGx increased both α- and β-adrenoceptor sensitivity of MBH tubulin. Px, while leaving the α-adrenoceptor supersensitive response unmodified, removed the β-adrenoceptor-mediated effect on tubulin because: (i) isoproterenol injection did not affect MBH tubulin in SCGx-Px rats; (ii) NE or L-dopa induced a depression of MBH tubulin which was partially impaired by propranolol in SCGx rats and was refractory to β-adrenergic blockade in SCGx-Px animals; (iii) the α-adrenergic blocker phentolamine abolished effectively NE or L-dopa effect on MBH tubulin in SCGx-Px rats but not in SCGx rats. Dose-related decreases of cerebral cortex tubulin after L-dopa treatment were essentially similar in SCGx, SCGx-Px or sham-operated rats. These results indicate that SCGx depresses NE uptake and increases α-adrenoceptor sites in MBH as well as the adrenoceptor-mediated response of MBH tubulin. A functionally relevant link between superior cervical ganglia and MBH appears to occur in the rat.

Retinal and pineal hydroxyindole-O-methyl transferases in the rat: changes following cervical sympathectomy, pinealectomy or blinding.

Retinal and pineal hydroxyindole— O—methyl transferases (HIOMT) exhibit 24–hr fluctuations with maxima during the light and dark period of the day, respectively. The effects of superior cervical ganglionectomy, pinealectomy or blinding on both enzymatic activities were investigated in male rats subjected to: a) ganglionectomy; b) pinealectomy; c) blinding; d) pinealectomy plus ganglionectomy; e) blinding plus ganglionectomy. Groups of rats were sacrificed every 4–8 hr during 2 days, and the HIOMT activity was determined in retinal and pineal homogenates. Ganglionectomy decreased retinal HIOMT activity, whereas pinealectomy increased it. Pinealectomy, or pinealectomy plus ganglionectomy, abolished the diurnal fluctuations in retinal HIOMT observed in intact or ganglionectomized rats. Blinding enhanced pineal HIOMT activity whereas ganglionectomy decreased it. Ganglionectomy, alone or combined with blinding, caused time—shifts in daily pineal HIOMT maxima. Norepinephrine (100–5OO μg ip) reversed the ganglio...

The effects of superior cervical ganglionectomy and/or bilateral adrenalectomy on the mitotic activity of the adult rat cornea

Superior cervical ganglionectomy inhibited mitotic activity in the cornea and increased mitotic duration. This effect was not eliminated by adrenalectomy. However, both operations appeared to lessen the marked mitotic depression found in the normal cornea in the late evening. Mitotic activity in the cornea was compared with that found previously in lenses from the same eyes. Although both tissues were affected by adrenal function and local sympathetic nerve activity the reactions bore no obvious relationship. Neither did the normal daytime mitotic variations found in the two tissues.

Influence of sympathetic innervation on carotid sinus baroreceptor activity.

Influence of sympathetic innervation on carotid sinus baroreceptor activity.

Effects of Superior Cervical Ganglionectomy on Aqueous Humor Dynamics

Various studies have been performed previously by several investigators regarding the relationship between the sympathetic nervous system and intraocular pressure. Out of such studies has come much controversy involving the effects of different types of anesthesia used by various investigators. Through the use of local anesthesia in a particular phase of our experiment, we have endeavored to arrive at certain values by tonographic measurements which, apparently, were not obtainable under similar experimental conditions when general anesthesia was employed. Early reviews were made by such investigators as Thiel, 16 Magitot, 11 and Duke-Elder. 2 Such studies were also made at a later date by Weinstein. 17 Loewenstein and Schoenberg 14 concluded from pupillographic studies that the central sympathetic factor plays a definite role in the beginning of primary simple glaucoma. Jaffe, 6 in later experiments, produced a drop in intraocular pressure in the eyes of cats following cervical sympathectomy operations. Following