Quantitative studies of superior cervical sympathetic ganglia in a variety of primates including man. I. The ratio of preganglionic fibers to ganglionic neurons

Estimates of the number of ganglionic neurons of superior cervical sympathetic ganglia and the number of preganglionic axons in the trunks just caudal to these ganglia were obtained from a sample of primates that included: man, chimpanzee, baboon, stump-tailed macaque, rhesus monkey, and squirrel monkey. The number of ganglionic neurons ranged from 63,625 in a squirrel monkey ganglion to 1,041,652 neurons in a human ganglion. Estimates of the number of preganglionic fibers varied between 2,285 in a cervical sympathetic trunk of a squirrel monkey and 12,008 in a human specimen. The resulting ratios of preganglionic fibers to ganglionic neurons ranged from 1:28 in a squirrel monkey ganglion to 1:196 in a human ganglion. The data reported in this study reveal considerable variation in the ratio of pre- to post-ganglionic neurons, and as was noted in regard to the number of cells in the ganglion, the ratios of ganglionic to preganglionic neurons appear to increase as a function of body size. In contrast, the number of preganglionic fibers does not increase as strikingly with body size, but varies greatly in the same species. The resulting ratio between the two orders of neurons is, therefore, less predictable than the number of ganglionic neurons in any given ganglion.     

Contributions of placodal and neural crest cells to avian cranial peripheral ganglia

The method of embryonic tissue transplantation was used to confirm the dual origin of avian cranial sensory ganglia, to map precise locations of the anlagen of these sensory neurons, and to identify placodal and neural crest-derived neurons within ganglia. Segments of neural crest or strips of presumptive placodal ectoderm were excised from chick embryos and replaced with homologous tissues from quail embryos, whose cells contain a heterochromatin marker. Placode-derived neurons associated with cranial nerves V, VII, IX, and X are located distal to crest-derived neurons. The generally larger, embryonic placodal neurons are found in the distal portions of both lobes of the trigeminal ganglion, and in the geniculate, petrosal and nodose ganglia. Crest-derived neurons are found in the proximal trigeminal ganglion and in the combined proximal ganglion of cranial nerves IX and X. Neurons in the vestibular and acoustic ganglia of cranial nerve VIII derive from placodal ectoderm with the exception of a few neural crest-derived neurons localized to regions within the vestibular ganglion. Schwann sheath cells and satellite cells associated with all these ganglia originate from neural crest. The ganglionic anlagen are arranged in cranial to caudal sequence from the level of the mesencephalon through the third somite. Presumptive placodal ectoderm for the VIIIth, the Vth, and the VIIth, IXth, and Xth ganglia are located in a medial to lateral fashion during early stages of development reflecting, respectively, the dorsolateral, intermediate, and epibranchial positions of these neurogenic placodes.     

The early development of cranial sensory ganglia and the potentialities of their component cells studied in quail-chick chimeras

The quail-chick marker system has been used to study the early developmental stages of the ganglia located along cranial nerves VII, IX, and X. The streams of neural crest cells arising from the rhombencephalic-vagal neural crest were followed from the onset of their migration up to the localization of crest cells in the trunk and root ganglia of these nerves. It was shown that two different populations of crest cells are segregated early as a result of morphogenetic movements in the hypobranchial region. The dorsal population gives rise to the root ganglia of nerves IX and X located close to the encephalic vesicles, where the crest cells differentiate both into neurons and into glia. In contrast, the ventral stream of neural crest cells contributes together with cells from epibranchial placodes to the trunk ganglia (geniculate, petrous, and nodose ganglia) of cranial nerves VII, IX, and X. The successive steps of the invasion of the placodal anlage by crest cells can be followed owing to the selective labeling of the neural crest cells. It appears that the latter give rise to the satellite cells of the geniculate, petrous, and nodose ganglia while the large sensory neurons originate from the placodes. The nodose ganglion has been the subject of further studies aimed to investigate whether neuronal potentialities can be elicited in the neural crest-derived cells that it contains. The ability to label selectively either the neurons or the glia by the quail nuclear marker made this investigation possible in the particular case of the nodose ganglion whose neurons and satellite cells have a different embryonic origin. By the technique already described (N. M. Le Douarin, M. A. Teillet, C. Ziller, and J. Smith, 1978, Proc. Nat. Acad. Sci. USA75, 2030–2034) of back-transplantation into the neural crest migration pathway of a younger host, it was shown that the presumptive glial cells of the nodose ganglion are able to remigrate when transplanted into a 2-day chick host and to differentiate into autonomic structures (sympathetic ganglion cells, adrenomedullary cells, and enteric ganglia). It is proposed as a working hypothesis that neuronal potentialities contained in the neural crest cells which invade the placodal primordium of the nodose ganglion are repressed through cell-cell interactions occurring between placodal and crest cells.     

Developmental potentialities in the nonneuronal population of quail sensory ganglia

Sensory ganglia taken from quail embryos at E4 to E7 were back-transplanted into the vagal neural crest migration pathway (i.e., at the level of somites 1 to 6) of 8- to 10-somite stage chick embryos. Three types of sensory ganglia were used: (i) proximal ganglia of cranial sensory nerves IX and X forming the jugular-superior ganglionic complex, whose neurons and nonneuronal cells both arise from the neural crest; (ii) distal ganglia of the same nerves, i.e., the petrosal and nodose ganglia in which the neurons originate from epibranchial placodes and the nonneuronal cells from the neural crest; (iii) dorsal root ganglia taken in the truncal region between the fore- and hindlimb levels. The question raised was whether cells from the graft would be able to yield the neural crest derivatives normally arising from the hindbrain and vagal crest, such as carotid body type I and II cells, enteric ganglia, Schwann cells located along the local nerves, and the nonneuronal contingent of cells in the host nodose ganglion. All the grafted cephalic ganglia provided the host with the complete array of these cell types. In contrast, grafted dorsal root ganglion cells gave rise only to carotid body type I and II cells, to the nonneuronal cells of the nodose ganglion, and to Schwann cells; the ganglion-derived cells did not invade the gut and therefore failed to contribute to the host's enteric neuronal system. Coculture on the chorioallantoic membrane of aneural chick gut directly associated with quail sensory ganglia essentially reinforced these results. These data demonstrate that the capacity of peripheral ganglia to provide enteric plexuses varies according to the level of the neuraxis from which they originate.     

大鼠脊神经节内交感神经支配的荧光组织化学与HRP示踪观察

本研究应用乙醛酸诱发儿茶酚胺（ＣＡ）荧光技术观察大鼠肾上腺素（ＮＡ）能神经在脊神经节内的分布;并应用ＨＲＰ顺、逆行追踪技术对脊神经节内ＮＡ能神经纤维的起源及其与脊神经节神经元的关系进行了探讨。荧光组织化学观察发现、有些神经节神经元胞体周围分布有带膨体的ＮＡ能神经末梢;有的紧密围绕脊神经节细胞——卫星细胞复合体。颈上交感神经节内注射霍乱毒素Ｂ亚单位结合ＨＲＰ（ＣＢ┐ＨＲＰ）,在同侧Ｃ３～６节段脊神经节内可见标记的点状纤维末梢紧邻于节细胞旁。Ｔ１１～Ｌ２节段脊神经节内注射ＨＲＰ后,在同侧椎旁交感链（Ｔ９～Ｌ１）内可见标记的交感节后神经元胞体。上述实验结果表明,交感节后神经元发出节后纤维可直接到达脊神经节内,与节细胞发生接触。本研究提示、交感神经在脊神经节水平可能参与躯体初级传入信息的调制     

Differences in the distribution and chemical coding between neurons in the inferior mesenteric ganglion supplying the colon and rectum in the pig

The distribution and chemical coding of neurons in the porcine left and right inferior mesenteric ganglion projecting to the ascending colon and rectum have been investigated by using combined retrograde tracing and double-labelling immunohistochemistry. The ganglion contained many neurons supplying both gut regions. The colon-projecting neurons (CPN) occurred exclusively in the cranial part of the ganglia where they formed a large cluster distributed along the dorso-lateral ganglionic border and a smaller cluster located close to the caudal colonic nerve output. The rectum-projecting neurons (RPN) formed a long stripe along the entire length of the lateral ganglionic border and, within the right ganglion only, a small cluster located close to the caudal colonic nerve output. Immunohistochemistry revealed that the vast majority of the CPN and RPN were noradrenergic (tyrosine-hydroxylase-positive). Many noradrenergic neurons supplying the colon contained somatostatin or, less frequently, neuropeptide Y. In contrast, a significant subpopulation of the noradrenergic RPN expressed neuropeptide Y, whereas only a small proportion contained somatostatin. A small number of the non-adrenergic RPN were cholinergic (choline-acetyltransferase-positive) and a much larger subpopulation of the nerve cells supplying both the colon and rectum were non-adrenergic and non-cholinergic. Many cholinergic neurons contained neuropeptide Y. The non-adrenergic non-cholinergic neurons expressed mostly somatostatin or neuropeptide Y and some of those projecting to the rectum contained nitric oxide synthase, galanin or vasoactive intestinal polypeptide. Many of both the CPN and RPN were supplied with varicose nerve fibres exhibiting immunoreactivity against Leu5-enkephalin, somatostatin, choline-acetyltransferase, vasoactive intestinal polypeptide or nitric oxide synthase The somatotopic and neurochemical organization of this relatively large population of differently coded inferior mesenteric ganglion neurons projecting to the large bowel indicates that these cells are probably involved in intestino-intestinal reflexes controlling peristaltic and secretory activities.     

Purification of the Chick Eye Ciliary Neuronotrophic Factor

Dissociated 8-day chick embryo ciliary ganglionic neurons will not survive for even 24 h in culture without the addition of specific supplements. One such supplement is a protein termed the ciliary neuronotrophic factor (CNTF) which is present at very high concentrations within intraocular tissues that contain the same muscle cells innervated by ciliary ganglionic neurons in vivo. We describe here the purification of chick eye CNTF by a 2 1/2-day procedure involving the processing of intraocular tissue extract sequentially through DE52 ion-exchange chromatography, membrane ultrafiltration-concentration, sucrose density gradient ultracentrifugation, and preparative sodium dodecyl sulfate-polyacrylamide gradient electrophoresis. An aqueous extract of the tissue from 300 eyes will yield about 10-20 micrograms of biologically active, electrophoretically pure CNTF with a specific activity of 7.5 X 10(6) trophic units/mg protein. Purified CNTF has an Mr of 20,400 daltons and an isoelectric point of about 5, as determined by analytical gel electrophoresis. In addition to supporting the survival of ciliary ganglion neurons, purified CNTF also supports the 24-h survival of cultured neurons from certain chick and rodent sensory and sympathetic ganglia. CNTF differs from mouse submaxillary nerve growth factor (NGF) in molecular weight, isoelectric point, inability to be inactivated by antibodies to NGF, ability to support the in vitro survival of the ciliary ganglion neurons, and inability to support that of 8-day chick embryo dorsal root ganglionic neurons. Thus, CNTF represents the first purified neuronotrophic factor which addresses parasympathetic cholinergic neurons.     

Distribution and immunohistochemical characteristics of neurons in the porcine caudal mesenteric ganglion projecting to the vas deferens and seminal vesicle

Combined retrograde tracing (using fluorescent tracer Fast Blue) and double-labelling immunofluorescence were used to study the distribution and immunohistochemical characteristics of neurons in the porcine caudal mesenteric ganglion projecting to the vas deferens and seminal vesicle. The distribution and immunohistochemical properties of neurons projecting to both organs were similar. As revealed by retrograde tracing, Fast Blue-positive neurons were located within the left and right ganglia, with a distinct predominance in the ipsilateral one. In the ipsilateral ganglion, the majority of the neurons were located caudally, along the dorso-lateral ganglionic border, suggesting a somatotopic organization of the ganglion. Immunohistochemistry revealed four populations of retrogradely labelled neurons (from the largest to the smaller one): tyrosine hydroxylase-positive/neuropeptide Y-negative (TH⁺/NPY^-), TH⁺/NPY⁺, TH^-/NPY^-, TH^-/NPY⁺. With respect to their surrounding nerve fibres, two subpopulations of the dye-labelled neurons could be distinguished. The small one consisted of solitary neurons receiving a strong calcitonin gene-related peptide- and Leu⁵-enkephalin-, and a less intense vasoactive intestinal peptide-immunoreactive innervation. The remaining neurons were poorly supplied by singular nerve fibres containing some of the investigated peptides. We conclude that the caudal mesenteric ganglion should be considered as a prominent source of adrenergic and/or NPY-positive innervation for the porcine male reproductive tract.     

Effects of preganglionic denervation and postganglionic axotomy on acetylcholine receptors in the chick ciliary ganglion

The regulation of nicotinic acetylcholine receptors (AChRs) in chick ciliary ganglia was examined by using a radiolabeled anti-AChR mAb to quantitate the amount of receptor in ganglion detergent extracts after preganglionic denervation or postganglionic axotomy. Surgical transection of the preganglionic input to the ciliary ganglion in newly hatched chicks caused a threefold reduction in the total number of AChRs within 10 d compared with that present in unoperated contralateral control ganglia. Surgical transection of both the choroid and ciliary nerves emerging from the ciliary ganglion in newly hatched chicks to establish postganglionic axotomy led to a nearly 10-fold reduction in AChRs within 5 d compared with unoperated contralateral ganglia. The declines were specific since they could not be accounted for by changes in ganglionic protein or by decreases in neuronal survival or size. Light microscopy revealed no gross morphological differences between neurons in operated and control ganglia. A second membrane component of cholinergic relevance on chick ciliary ganglion neurons is the alpha-bungarotoxin (alpha-Bgt)-binding component. The alpha-Bgt-binding component also declined in number after either postganglionic axotomy or preganglionic denervation, but appeared to do so with a more rapid time course than did ganglionic AChRs. The results imply that cell-cell interactions in vivo specifically regulate both the number of AChRs and the number of alpha-Bgt-binding components in the ganglion. Regulation of these neuronal cholinergic membrane components clearly differs from that previously described for muscle AChRs.     

Distribution of NADPH-diaphorase activity in rat paravertebral,prevertebral and pelvic sympathetic ganglia

Summary Paravertebral (superior cervical and stellate), prevertebral (coeliac-superior mesenteric, inferior mesenteric) and pelvic (hypogastric) sympathetic ganglia of the rat were investigated by enzyme histochemistry to ascertain the distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase) activity. In the paravertebral ganglia the majority of the sympathetic neuronal perikarya contained lightly and homogeneously distributed formazan reaction product but there was a range of staining intensities amongst the neuron population. In contrast, in the prevertebral ganglia, intense NADPH-diaphorase staining was present in certain neurons. Firstly, a population of neurons of the coeliac-superior mesenteric ganglion complex were surrounded by densely NADPH-diaphorase-positive baskets of fibres and other stained fibres were seen in interstitial nerve bundles and in nerve trunks connected to the ganglion complex. Secondly, in both the inferior mesenteric ganglion and hypogastric ganglion there were many very intensely NADPH-diaphorase positive neurons. Stained dendritic and axonal processes emerged from these cell bodies. In both ganglia this population of neurons was smaller in size than the lightly stained ganglionic neurons and commonly had only one long (presumably axonal) process. The similarity of these highly NADPH-diaphorase-positive neurons with previously described postganglionic parasympathetic neurons in the hypogastric ganglion is discussed.     

Comparing the somal size and nuclear positions of the monkey stellate and coeliac ganglion cells

The stellate and coeliac ganglia of 2 Macaque monkeys were cut serially at 1 micron thickness and analysed. Results from the analysis of 82 stellate and 60 coeliac ganglion cells in 1 monkey show that in cross-sections, the neuronal nuclei may be eccentric, centric or nearly centric and remain so throughout the longitudinal extent of the neuron. In both ganglia, the majority of neurons possess eccentric nuclei, but in the coeliac ganglion, the percentage of neurons with centric and/or nearly centric nuclei is higher (41.7%) than that in the stellate ganglion (26.3%). While 5% of neurons in the coeliac ganglion are binucleated, no binucleated neurons were found in the stellate ganglion. The somal size ranges of the stellate (10-39 microns) and the coeliac (14.5-45 microns) ganglion neurons as obtained from both monkeys are quite close. The percentage frequency distribution of the stellate ganglion neurons in monkey 1 was also quite similar to that of the coeliac ganglion neurons. It is concluded that different neuronal size is not likely to be associated with different target organs.     

Sympathetic and sensory innervation of small intensely fluorescent (SIF) cells in rat superior cervical ganglion

The sympathetic ganglion contains small intensely fluorescent (SIF) cells derived from the neural crest. We morphologically characterize SIF cells and focus on their relationship with ganglionic cells, preganglionic nerve fibers and sensory nerve endings. SIF cells stained intensely for tyrosine hydroxylase (TH), with a few cells also being immunoreactive for dopamine β-hydroxylase (DBH). Vesicular acetylcholine transporter (VAChT)-immunoreactive puncta were distributed around some clusters of SIF cells, whereas some SIF cells closely abutted DBH-immunoreactive ganglionic cells. SIF cells contained bassoon-immunoreactive products beneath the cell membrane at the attachments and on opposite sites to the ganglionic cells. Ganglion neurons and SIF cells were immunoreactive to dopamine D2 receptors. Immunohistochemistry for P2X3 revealed ramified nerve endings with P2X3 immunoreactivity around SIF cells. Triple-labeling for P2X3, TH and VAChT allowed the classification of SIF cells into three types based on their innervation: (1) with only VAChT-immunoreactive puncta, (2) with only P2X3-immunoreactive nerve endings, (3) with both P2X3-immunoreactive nerve endings and VAChT-immunoreactive puncta. The results of retrograde tracing with fast blue dye indicated that most of these nerve endings originated from the petrosal ganglion. Thus, SIF cells in the superior cervical ganglion are innervated by preganglionic fibers and glossopharyngeal sensory nerve endings and can be classified into three types. SIF cells might modulate sympathetic activity in the superior cervical ganglion.     

Origins of the afferent fibers to the cat superior cervical ganglion.

The origins of the afferent fibers to the cat's superior cervical ganglion (SCG) were demonstrated by using the retrograde horseradish peroxidase tracing method. We found that the preganglionic neurons were located in the spinal segments C8-T5, particularly in T1-T3. These neurons were situated mainly in the intermediolateral column. The extra-SCG neurons along with the cervical sympathetic trunk originated ipsilaterally from the middle cervical and stellate ganglia, and contralaterally from the caudal part of the SCG. Labeled neurons also originated from the mandibular division of the trigeminal ganglion. Our results demonstrated that many fiber sources projected to the SCG, which plays a complicated synaptic role in controlling the visceral organs of the head and neck region.     

Dopamine-β-hydroxylase-, neurotensin-, substance P-, vasoactive intestinal polypeptide- and enkephalin-immunohistochemistry of paravertebral and prevertebral ganglia in the cat

Summary Para and prevertebral ganglia of the cat were investigated for immunoreactivity (IR) against neurotensin (NT), vasoactive intestinal polypeptide (VIP), substance P (SP) and enkephalin (ENK). Dopamine--hydroxylase- (DBH)-IR was studied in consecutive sections to correlate the distribution of noradrenergic/adrenergic neurons with that of peptidergic nerve fibres and cells.In paravertebral (cervical and thoracic) ganglia, NT-IR or ENK-IR nerve fibres were seen in areas in which DBH-IR fibre networks also occurred. NT-IR varicosities were often in close contact with perikarya of principal ganglionic cells on which DBH-IR varicosities also terminated. Such an association was rarely seen between ENK-IR and DBH-IR fibre baskets. NT-IR and ENK-IR fibre baskets were not found to occur around the same principal ganglionic cell. The distribution of VIP-IR and SP-IR nerve fibres did not coincide with that of DBH-IR fibres.In prevertebral ganglia (celiac-superior mesenteric and inferior mesenteric) DBH-IR or VIP-IR varicosities surrounded the majority of principal ganglionic neurons. ENK-IR or SP-IR fibres were closely associated with only a minority of the neurons; NT-IR networks were rather sparse. Some principal neurons were approached by DBH-IR fibres and by different peptide-IR fibres.In paravertebral ganglia some principal ganglionic cells contained VIP-IR, a few of which were also surrounded by NT-IR varicosities. VIP-IR perikarya in prevertebral ganglia were extremely rare. No NT-IR, SP-IR or ENK-IR principal ganglionic cells were found.Glomus-like paraganglionic cell clusters in paravertebral and prevertebral ganglia exhibited DBH-IR cell bodies. Moreover, the clusters also contained ENK-IR or SP-IR cells. NT-IR varicosities were observed adjacent to clustered paraganglionic cells. Only few singly located paraganglionic cells were NT-IR or ENK-IR.The differential distribution of peptide-IR nerve endings in the investigated ganglia suggests a regulation of impulse transmission that seems to be related to the target organs.Fellow of the Heisenberg foundationSupported by the DFG, grants He 919/5, Re 520/1-2, and SFB 90 Carvas, Heidelberg     

The cranial sensory ganglia in culture: Differences in the response of placode-derived and neural crest-derived neurons to nerve growth factor

Explants of cranial sensory ganglia and dorsal root ganglia from embryonic chicks of 4 to 16 days incubation (E4 to E16) were grown for 24 hr in collagen gels with and without nerve growth factor (NGF) in the culture medium. NGF elicited marked neurite outgrowth from neural crest-derived explants, i.e., dorsal root ganglia, the dorsomedial part of the trigeminal ganglion, and the jugular ganglion. This response was first observed in ganglia taken from E6 embryos, reached a maximum between E8 and E11, and gradually declined through E16. Explants in which the neurons were of placodal origin varied in their response to NGF. There was negligible neurite outgrowth from explants of the ventrolateral part of the trigeminal ganglion and the vestibular ganglion grown in the presence of NGF. The geniculate, petrosal, and nodose ganglia exhibited an early moderate response to NGF. This was first evident in ganglia taken from E5 embryos, reached a maximum by E6, and declined through later ages, becoming negligible by E13. Dissociated neuron-enriched cultures of vestibular, petrosal, jugular, and dorsal root ganglia were established from embryos taken at E6 and E9. At both ages NGF elicited neurite outgrowth from a substantial proportion of neural crest-derived neurons (jugular and dorsal root ganglia) but did not promote the growth of placode-derived neurons (vestibular and petrosal ganglia). Our findings demonstrate a marked difference in the response of neural crest and placode-derived sensory neurones to NGF. The data from dissociated neuron-enriched cultures suggest that NGF promotes survival and growth of sensory ganglionic neurons of neural crest origin but not of placodal origin. The data from explant cultures suggest that NGF promotes neurite outgrowth from placodal neurons of the geniculate, petrosal, and nodose ganglia early in their ontogeny. However, we argue that this fibre outgrowth emanates not from the placodal neurons but from neural crest-derived cells which normally give rise only to satellite cells of these ganglia.     

The development of the neurons of the glossopharyngeal (IX) and vagal (X) sensory ganglia in chick embryos

The timetable of cell generation, neuronal death and neuron numbers in the fused proximal glossopharyngeal (IX) and vagal (X) ganglion and distal IX and X ganglia were studied in normal and nerve growth factor (NGF) treated chick embryos. 3H-thymidine was injected between the 3rd and 7th days of incubation and embryos sacrificed on the 11th day. Neurons in the distal IX and X ganglia were generated between the 2nd and 5th days of incubation, the peak mitotic activity occurring on the 4th and 3rd days, respectively. Neurons of the proximal IX and X ganglion were generated between the 4th and 7th days, with maximum neuron generation on the 5th day of incubation. Counts of neurons in the 3 ganglia between the 5th and 18th days of incubation showed a maximum of 22,000 on the 8th day in the proximal IX and X ganglion and this decreased to 12,000 by the 13th day. In the distal IX ganglion, the neuron number decreased by 44% from 4,500 on the 6th day to 2,500 by the 11th day. A similar decrease of 43% was found in the distal X ganglion, the neuron number falling from 11,500 on the 7th day to 6,500 by the 11th day of incubation. Neuronal cell death in these ganglia extended from the 5th to the 12th day of incubation, maximum cell death occurring at or after the cessation of mitotic activity. NGF administration from the 5th to the 11th day of incubation did not have a measurable effect on the neurons of proximal IX and X and distal IX ganglia, but increased neuronal survival by 30% in the distal X ganglion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphometric study of the superior cervical and stellate ganglia of spontaneously hypertensive rats during the prehypertensive stage

To compare the functional state of the superior cervical (SCG) and stellate sympathetic ganglia (SG) of spontaneously hypertensive rats (SHR) with those of age-matched normotensive Wistar Kyoto rats (WKY), ganglion cell volume and area occupied by ganglion cells relative to each whole ganglionic area were morphometrically examined using the Texture Analyse System (TAS) in rats at 0, 10 and 30 days of age. The weight of each ganglion relative to animal weight was also measured. The ganglion cell volume and the relative area of ganglionic cells in both ganglia of SHR were significantly larger (P less than 0.05) than those of age-matched WKY at ages 0 and 10 days after birth. The relative ganglionic weights of SHR were significantly larger (P less than 0.01) compared with those of WKY at all ages examined, except for SG at 0 days after birth. These results show that the relative volume of sympathetic ganglion cells is greater in both SCG and SG of SHR than that of WKY, suggesting that hyperfunction of sympathetic ganglia occurs at the prehypertensive stage as a primary factor in the development of hypertension in SHR.     

Activation of ETB receptors increases superoxide levels in sympathetic ganglia in vivo

Dai and colleagues (Dai X, Galligan JJ, Watts SW, Fink GD, and Kreulen DL. Hypertension 43: 1048-1054, 2004) found that endothelin (ET) stimulated O2- production in sympathetic ganglion neurons in vitro by activating ET(B) receptors. The objective of the present study was to determine whether activation of ET(B) receptors in vivo elevates O2- levels in sympathetic ganglia. Because ET(B) receptor activation increases blood pressure, we also sought to determine whether alteration in O2- levels was a direct effect of ET(B) receptor activation on sympathetic ganglia or an indirect consequence of hypertension. Male Sprague-Dawley rats received intravenous infusions of either the specific ET(B) receptor agonist sarafotoxin 6c (S6c; 5 pmol.kg(-1).min(-1)) or isotonic saline at 0.01 ml/min (control) for 120 min. To measure O2- levels, we removed the inferior mesenteric ganglion immediately after infusion and stained it with dihydroethidine (DHE). Mean arterial pressure increased 26.6 +/- 1.7 mmHg in the S6c-treated rats and 3.65 +/- 6 mmHg in control rats. Measurements of average pixel intensity revealed that the DHE fluorescence in ganglionic neurons and surrounding glial cells were 96.7% and 160% greater in S6c-treated than in control rats, respectively. To evaluate the effect of elevated blood pressure on O2- production, a separate group of rats received phenylephrine (PE; 10 mug.kg(-1).min(-1) iv) for 2 h. MAP increased 31 +/- 1.2 mmHg in PE-infused rats. The DHE fluorescence intensity in ganglia of PE-infused rats was significantly greater than that of control rats, 137.7% in neurons and 104.6% in glia but significantly lower than in ganglia from S6c rats. We conclude that ET(B) receptor activation in vivo significantly enhances O2- levels in sympathetic ganglia, due to both pressor effects and direct stimulation of ET(B) receptors in ganglion cells.     

Morphometric study of the superior cervical and stellate ganglia of spontaneously hypertensive rats during the prehypertensive stage

To compare the functional state of the superior cervical (SCG) and stellate sympathetic ganglia (SG) of spontaneously hypertensive rats (SHR) with those of age-matched normotensive Wistar Kyoto rats (WKY), ganglion cell volume and area occupied by ganglion cells relative to each whole ganglionic area were morphometrically examined using the Texture Analyse System (TAS) in rats at 0, 10 and 30 days of age. The weight of each ganglion relative to animal weight was also measured. The ganglion cell volume and the relative area of ganglionic cells in both ganglia of SHR were significantly larger (P<0.05) than those of age-matched WKY at ages 0 and 10 days after birth. The relative ganglionic weights of SHR were significantly larger (P<0.01) compared with those of WKY at all ages examined, except for SG at 0 days after birth. These results show that the relative volume of sympathetic ganglion cells is greater in both SCG and SG of SHR than that of WKY, suggesting that hyperfunction of sympathetic ganglia occurs at the prehypertensive stage as a primary factor in the development of hypertension in SHR.     

Quantitative studies of superior cervical sympathetic ganglia in a variety of primates including man. II. Neuronal packing density

The volumes of a sample of primate superior cervical sympathetic ganglia were measured and related to body weight and to the number of ganglionic neurons. Estimates of volumes of the ganglia varied between 1.956 mm³ in squirrel monkey and 173.530 mm³ in a human specimen. Average cell densities for the ganglia ranged from 4,455 cells/mm³ in a human ganglion to 32,528 cells/mm³ in a squirrel monkey ganglion. Mean cell territories varied from 0.0000307 mm³ in a squirrel monkey ganglion to 0.0002245 mm³ in a human ganglion. Analysis of the data reveals striking trends of correlation between body size, volume of ganglia, and average cell territories. Since similar correlations have been described for other types of neuronal cell aggregates, it is suggested that for any given nucleus, ganglion or cortical area, the neuronal packing density varies as a function of body size.