Immunohistochemical detection of GTP-binding regulatory protein (Go) in the autonomic nervous system including the enteric nervous system, superior cervical ganglion and adrenal medulla

The localization of a GTP-binding regulatory protein, Go, in the autonomic nervous system including the enteric nervous system, superior cervical ganglion, and adrenal medulla, has been immunohistochemically examined by use of affinity-purified antibody against the alpha-subunit of Go. In the small intestine, dense Go-immunoreactive products were localized on the enteric nervous system, i.e. the myenteric plexus of Auerbach and the submucosal plexus of Meissner. In the superior cervical ganglion, presynaptic terminals were strongly immunoreactive to the Go antibody. The adrenal medulla was stained with this antibody, but the adrenal cortex was not immunoreactive to this antibody. Thus, the present study strongly suggests that Go is localized in the autonomic nervous system and plays its role in transmembrane signal transmission in this system.

Quantification and characterization of enkephalins in the upper part of the cat digestive tract and the coeliac ganglia

The [Met]enkephalin, [Leu]enkephalin and [Met]enkephalin-arg-gly-leu contents of the upper part of the digestive tract (lower oesophageal sphincter, fundus, antrum, pylorus, duodenum, ileum) and coeliac ganglia of the cat were determined and identified. The enkephalin content of all the structures studied, expressed in femtomole/mg of wet tissue, was found to range from 83 to 446 with [Met]enkephalin; 19 to 63 with [Leu]enkephalin; 2.5 to 13 with [Met]enkephalin-arg-gly-leu. In the muscular and plexus layers the [Met]- and [Leu]enkephalin contents increase gradually from the lower oesophageal sphincter to the pylorus and then decrease from the duodenum to the ileum. The [Met]enkephalin versus [Leu]enkephalin ratio is 2.7 in the coeliac ganglia and ranges from 4.3 to 8.1 in the areas of the digestive tract investigated. In addition, the presence of authentic [Met]- and [Leu]enkephalin was confirmed in all the structures assayed by high pressure liquid chromatography. Owing to the low amounts of [Met]enkephalin-arg-gly-leu detected in individual samples of the coeliac ganglia and in the areas of the digestive tract investigated, it was not possible to characterize this peptide using high pressure liquid chromatography and therefore to confirm the presence of authentic [Met]enkephalin-arg-gly-leu in these structures. The differences in the enkephalin concentrations observed among these various areas of the digestive tract suggest that these peptides may act differently from one area to another, thus playing a complex integrative role in the nervous control of gastrointestinal tract motility.

Measurement of neuronal Ca2+ transients using simultaneous microfluorimetry and electrophysiology

Fluorescent indicator molecules, such as fura-2, are useful probes for studying the concentrations of ions in single cells. A key feature of these fluorescent dyes is the shift in their excitation spectra upon binding the ion, thus making alternate excitation from two wavelengths desirable. In this report we describe an inexpensive system for making simultaneous electrophysiological and dual excitation fluorescence measurements using equipment much of which is available in a typical biophysical laboratory. In order to synchronize the fluorescence signal with the appropriate excitation wavelength we devised a simple computer program which uses the output of photodiodes placed in the excitation beam to determine which wavelength is illuminating the cell. We also describe the use of a liquid light guide to transmit excitation illumination from the light source to the epifluorescence port of the microscope in order to isolate a perfusion chamber from light, electrical noise and vibration. A sensitive light detection system was assembled using a photomultiplier tube and discriminator that took advantage of sampling single unit events obtained with photon counting rather than the analog of anode current. However, rather than employing a sophisticated and expensive photon counting system, a filter was used to integrate the signal so that an analog output could be presented to a multichannel analog to digital converter commonly used for electrophysiological recordings.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in neuronal lipid composition between superior cervical ganglia and nodose ganglia of the rat

The lipid content and composition of rat superior cervical ganglia containing sympathetic motor neurons and nodose ganglia containing parasympathetic sensory neurons were studied for the first time to elucidate the mechanism of the different effects of exogenous gangliosides on these neurons in the culture medium. The ganglioside content of the superior cervical ganglia was almost 3-times that of the nodose ganglia. Although both ganglia contained GM3, GD3, GD1b and GT1b as major gangliosides, the nodose ganglia additionally contained a significant amount of sialosyllactoneotetraosylceramide LM1 (10% of total sialic acids). Contrasting with nodose ganglia, vagus fiber and dorsal root ganglia of rats, superior cervical ganglia had a higher content of sulfatide than galactosylceramide. The phospholipid content was lower in superior cervical ganglia than in nodose ganglia. Superior cervical ganglia contained less ethanolamine plasmalogen and more phosphatidylcholine than nodose ganglia. Sphingomyelin in superior cervical ganglia contained mainly medium-chain fatty acids, while that in nodose ganglia contained mainly longer-chain fatty acids. Differences in the fatty acid composition of glycerophospholipids were also observed. The results indicate that the properties of neuronal cell membranes from superior cervical ganglia and nodose ganglia are quite different, and that the differences may reflect the physiological roles of these ganglia.

Regulation of tyrosine hydroxylase and phenylethanolamine N-methyltransferase mRNA levels in the sympathoadrenal system by the pituitary-adrenocortical axis

The pituitary-adrenocortical axis plays a complex role in the regulation of the levels of enzymes of the catecholamine biosynthetic pathway. In this report we have explored molecular mechanisms of these regulations, by examining the effects of hypophysectomy (HPX) and dexamethasone (DEX) on tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) mRNA levels in the adrenal medulla (AM) and superior cervical ganglia (SCG). Three weeks after hypophysectomy weights (-48%), total RNA (-49%), and DNA (-22%) contents in AM were significantly reduced, when compared to sham-operated animals (SO). In SCG decreases in weight (-23%) and in the ratio of RNA/DNA (-25%) were also found. TH mRNA contents paralleled decreases in total RNA levels and no significant change in the relative abundance of TH mRNA was found. When HPX rats were injected for 5 days with DEX (1 mg/kg, i.p.), TH mRNA levels in the SCG (+51%) and in the AM (+74%) were significantly increased when compared to saline-treated HPX animals. DEX given to SO rats increased TH mRNA in SCG (+49%); a 27% increase in TH mRNA in the AM was also observed. The relative abundance of PNMT mRNA in the AM was reduced after hypophysectomy (-64%). This decrease was completely reversed by DEX. In contrast, DEX did not affect PNMT mRNA levels in the AM of SO rats. PNMT mRNA was not detected in SCG of saline- or DEX-treated rats. In conclusion, our findings suggest that the pituitary-adrenocortical axis is involved in the regulation of the steady-state levels of TH and PNMT mRNAs. This regulation involves: (1) induction of TH mRNA contents in AM and SCG by increased plasma glucocorticoid levels; and (2) maintenance of the steady-state levels of PNMT mRNA in AM by glucocorticoid-dependent mechanisms.

Roles of the pituitary-adrenocortical axis in control of the native and cryptic enkephalin levels and proenkephalin mRNA in the sympathoadrenal system of the rat

The effects of hypophysectomy (HPX) and dexamethasone (DEX) on the levels of Met5-enkephalin (ME), ME precursors, and the abundance of proenkephalin (pEK) mRNA, were examined in the adrenal medulla (AM) and superior cervical ganglia (SCG). To assess possible changes in enkephalin processing, both cryptic (after trypsin and carboxypeptidase B digestions) and native (without enzyme digestions) ME-like immunoreactivity (ME-LI) was measured. Three weeks after HPX the proportion of pEK mRNA to the total RNA content in the AM was not significantly changed when compared to sham-operated (SO) animals. Total (native + cryptic) ME-LI was decreased by 45% in the AM of HPX rats. This decrease was paralleled by a 58% depletion of AM proteins. Cryptic ME-LI was also reduced by 43%. In contrast, native ME-LI was not altered after HPX, indicating enhanced processing of ME precursors. Treatment with DEX (5 daily injections--1 mg/kg, i.p.) increased the relative abundance of pEK mRNA (+27%) and total ME-LI in the AM of HPX group, but not in SO group. Native ME-LI, cryptic ME-LI, and their ratio were not significantly affected by DEX in the AM of HPX or SO rats. In SCG, the relative abundance of pEK mRNA decreased by 25% after hypophysectomy. Total and cryptic ME-LI in the SCG of HPX rats were not changed when compared to SO rats. In contrast, HPX reduced native ME-LI suggesting decreased processing of ME precursors. Similarly, as in AM, DEX produced increase in the SCG pEK mRNA only in HPX (+68%) and not in the SO rats. In SCG, DEX produced decreases in total ME-LI which could be attributed to an increased enkephalin release. An overall reduction of cryptic ME-LI was also observed after DEX, whereas native ME-LI remained unchanged suggesting increased processing of enkephalins. Our findings indicate that the pituitary adrenocortical axis controls the relative proportions of ME to its precursors, and that this control involves both glucocorticoid-dependent (SCG) and glucocorticoid-independent (AM) mechanisms. In contrast, our studies do not suggest specific control of pEK synthesis by the pituitary adrenocortical axis. The pituitary adrenocortical axis may also influence the relative contents of ME and catecholamines in the AM and SCG. The ratio of ME/catecholamines increased after HPX (AM and SCG) and after DEX (SCG). Such regulation may contribute to the control of co-transmitter output in the sympathoadrenal system.

Substance P- and vasoactive intestinal polypeptide (VIP)-immunoreactive nerve fibers in relation to ovarian postganglionic perikarya in para- and prevertebral ganglia: evidence from combined retrograde tracing and immunocytochemistry

Retrograde neuronal tracing with the fluorescent dye True Blue and immunocytochemistry were utilized to examine postganglionic sympathetic neurons in para- and prevertebral ganglia projecting to the rat ovary. Perikarya in both ganglia were labeled with True Blue after application of the tracer to either the superior ovarian or ovarian plexus nerve. After application of True Blue to the superior ovarian nerve, 17% of the labeled cells in paravertebral ganglia were immunoreactive for vasoactive intestinal polypeptide. In contrast, after application of True Blue to the ovarian plexus nerve, approximately 1% of the labeled cells in paravertebral ganglia were immunoreactive for the same polypeptide. Some vasoactive intestinal polypeptide-immunoreactive perikarya in paravertebral ganglia were not labeled with True Blue. In some cases, substance P- and vasoactive intestinal polypeptide-immunoreactive fibers were closely apposed to True Blue-labeled perikarya in para- and prevertebral ganglia. Paravertebral vasoactive intestinal polypeptide-immunoreactive perikarya projecting to the ovary presumably participate directly in the control of various ovarian functions. Substance P- and vasoactive intestinal polypeptide-immunoreactive fibers closely apposed to perikarya projecting to the ovary may participate indirectly in the control of various ovarian functions by affecting the activity of ovarian postganglionic neurons.

Developmental changes of nerve growth factor levels in sympathetic ganglia and their target organs

The predominant source of nerve growth factor (NGF) used by mature sympathetic neurons originates in their target organs (Heumann, R., Korsching, S., Scott, J., and Thoenen, H. (1984), EMBO J. 3, 3183-3189; Korsching, S., and Thoenen, H. (1985), J. Neurosci. 5, 1058-1061). We have determined the NGF content of two sympathetically innervated mouse organs, submandibular gland and heart ventricle, and of sympathetic ganglia from mouse and rat between embryonic Day 12 (E12) and adulthood. NGF levels were measured by a two-site enzyme immunassay (Korsching, S., and Thoenen, H. (1983), Proc. Natl. Acad. Sci. USA 80, 3513-3516). In heart ventricle and submandibular gland, NGF first became detectable around the time of initial innervation by sympathetic neurons (E12 and E13, respectively) and increased respectively 14- and 7-fold in the following 2 days, to reach adult levels already at E14 for heart ventricle (1.4 +/- 0.2 ng NGF/g wet wt). NGF in the superior cervical ganglion (SCG) was first detected at the same time as in its target organ, the submandibular gland. NGF content in the SCG then increased 6-fold during the next 2 days and continued to increase until the end of the third postnatal week, when adult levels were reached. Although the levels of NGF in the adult mouse submandibular gland are sexually dimorphic and six orders of magnitude higher than those in other sympathetic target organs, no sex difference in the NGF content was found in either developing submandibular gland or SCG until the end of the third postnatal week. Moreover, the steep NGF increase observed in the male submandibular gland after postnatal Day 18 (250-fold within the following 3 days and up to the 55,000-fold in the next 7 days) was not reflected in a corresponding increase in the NGF content of the male SCG. These data indicate that, in accordance with earlier findings (see Levi-Montalcini, R., and Angeletti, P. U. (1968), Physiol. Rev. 48, 534-569), SCG neurons do not have access to the large amounts of NGF synthesized during and after adolescence in the mouse submandibular gland. Our results support the concept that initial fiber outgrowth of sympathetic neurons is neither dependent on NGF nor mediated by it. The time course of NGF levels in the SCG is consistent with the concept that sympathetic neurons are provided with NGF by means of retrograde axonal transport from the innervated organs already early in development.

Subcellular fractionation of bovine ganglion stellatum: co-storage of noradrenaline, Met-enkephalin and neuropeptide Y in large 'dense-cored' vesicles

The subcellular localization of noradrenaline, Met-enkephalin and neuropeptide Y was studied in homogenates of bovine ganglion stellatum. After differential centrifugation most of the noradrenaline (70%) was found soluble, while both neuropeptide Y and Met-enkephalin were sedimented for more than 65%. However, the 3 substances co-sedimented mainly in the microsomal fraction. The microsomal fraction was further analyzed by differential and equilibrium density gradient centrifugation. In both types of gradient, Met-enkephalin and neuropeptide Y were found in the more dense region of the gradient, coinciding with the main peak of noradrenaline. In this fraction, the molar ratio of Met-enkephalin to noradrenaline was 1:95. The corresponding molar ratio for neuropeptide Y to noradrenaline was 1:253. These results indicate that neuropeptide Y and Met-enkephalin are stored with noradrenaline in 'heavy' or large 'dense cored' vesicles in the cell bodies of sympathetic neurons of bovine ganglion stellatum. We present here for the first time biochemical evidence for the co-localization of neuropeptides and a classical transmitter in a neuronal cell body.

Immunohistochemical localization of parvalbumin in rat and monkey autonomic ganglia

The cellular distribution of parvalbumin-like immunoreactivity in autonomic ganglia such as superior cervical sympathetic ganglia, paravertebral sympathetic chain ganglia (T6), ciliary ganglia and enteric ganglia was investigated by immunohistochemical peroxidase-antiperoxidase methods using an antiserum against rat skeletal muscle parvalbumin. We detected parvalbumin-like immunoreactivity in almost all neurons of rat superior cervical sympathetic ganglia and other paravertebral sympathetic chain ganglia, where the antigen was located in the cytoplasm but the nuclei were not labelled. No neurons positive for parvalbumin-like immunoreactivity were observed in rat ciliary ganglia or enteric ganglia. In monkey, almost all neurons of the superior cervical sympathetic ganglia contained parvalbumin-like immunoreactivity, but none of the neurons of the ciliary ganglia were labelled with the antiserum to parvalbumin. These results suggest that parvalbumin-like immunoreactivity exists in a specific subpopulation of the neurons of the autonomic nervous system.

Analysis of myelin proteins in sympathetic peripheral nerve of adult rats

Biochemical analyses of myelin proteins in rat sympathetic peripheral nerve were correlated with morphological observations. Myelin proteins in superior cervical ganglia (SCG) and the paravertebral (thoraco-lumbar) chain of ganglia were quantitated by immunoassays and examined qualitatively by Western blotting. The results were compared to those obtained on sciatic nerves from the same animals. In rats aged one year, the concentrations of PO glycoprotein and myelin basic protein (MBP) in SCG were about 1% of those in sciatic nerve, consistent with the relatively low numbers of myelinated fibers in sympathetic nerve. The relative concentration of myelin-associated glycoprotein (MAG) was higher, being 6.7% of that in sciatic nerve. The latter finding is probably due to the greater proportion of MAG-containing membranes (periaxonal, paranodal, and Schmitt-Lanterman incisures) in myelinated fibers of the SCG, in which the internodes are both short and thinly myelinated. The proportion of the 21 kDa, 18 kDa and 17 kDa forms of MBP relative to the 14 kDa form was much higher in SCG than in sciatic nerve, probably reflecting the fact that myelin formation continues actively during adult life in the ganglia, whereas the deposition of myelin is complete at a much earlier age in somatic nerves. The levels of myelin proteins were 2- to 3-fold higher in the paravertebral chain ganglia. These studies indicate that quantitation of myelin proteins in sparsely myelinated sympathetic nerve tissue is feasible and provide a baseline for further studies on the control of myelination in sympathetic nerve during adult life.

Fine-structural localization of neuropeptide tyrosine (NPY)-like immunoreactivity in the neuronal somata of colchicine-pretreated celiac ganglia of rats

In colchicine-pretreated cells of sympathetic ganglia, intensely NPY-immunoreactive material was localized within vacuoles and vesicles of the disorganized, widely dispersed Golgi apparatus. Intensely positive large granular vesicles, which are known to be one of major storage sites of various peptides in the autonomic nerve endings, were essentially unobserved in the perikaryal cytoplasm. The present finding provides evidence that one pool of NPY-like immunoreactivity is localized in the Golgi apparatus of colchicine-pretreated as well as normal sympathetic ganglion cells. It is also clear that visualization of NPY-immunoreactive somata by colchicine-pretreatment in the sympathetic ganglia is due to the accumulation of the neuropeptide in the disorganized Golgi stacks instead of increased amount of the large granular vesicles containing NPY.

Monoclonal antibodies to substance P: production, characterization of their fine specificities, and use in immunocytochemistry

Five hybrid clones secreting antibodies to the neuropeptide substance P have been obtained by somatic cell fusion of mouse myeloma cells with splenocytes from immunized mice of the Biozzi strain. To perform rapid and sensitive screening tests as well as to study the fine specificities of each monoclonal antibody, we developed a new enzyme immunoassay of substance P using acetylcholinesterase as label. All five monoclonal antibodies were directed to the C-terminal pentapeptide of substance P, especially to the Phe7 residue. They cross-reacted with neurokinin A and to some extent with neurokinin B but not with other nontachykinin mammalian peptides. One monoclonal antibody (SP 14) was used for immunocytochemical experiments in the rat spinal cord and spinal ganglion, both at the light and electron microscopic levels. A strong specific neurokinin-like immunoreactivity was observed in cell bodies, nerve fibers, and terminals, with a very low background staining. Finally, the affinities of several analogues of substance P for SP 14 monoclonal antibody were shown to be correlated with their biological activities, as measured by their hypotensive effects in vivo. These findings suggested a strong structural resemblance between the combining site of the antibody and that of the physiological substance P receptor.

Distinct substance P and calcitonin gene-related peptide immunoreactive nerves in the guinea pig eye

Using a double labeling indirect immunofluorescent technique, we studied the guinea pig trigeminal ganglion and eye for co-localization of substance P and calcitonin gene-related peptide. In the trigeminal ganglion, the number of neurons immunoreactive for calcitonin gene-related peptide significantly outnumber those immunoreactive for substance P, but virtually all substance P positive neurons are immunoreactive for calcitonin gene-related peptide. In the eye, a complex pattern of co-localization is present; both peptides co-localize in most immunoreactive nerve fibers. Nerve fibers immunoreactive only for calcitonin gene-related peptide tend to be concentrated in the cornea and posterior ciliary body. Nerve fibers immunoreactive only for substance P are present in relation to both iris muscles. Sensory denervation by intracranial transection of the ophthalmic and maxillary nerves fails to eliminate these substance P positive but CGRP negative iris nerve fibers. These findings indicate an alternative origin for substance P immunoreactive nerves supplying the iris muscles in this species.

Effects of prenatal undernutrition on prevertebral sympathetic neurons in the rat: a morphological and fluorescence histochemical study

The effects of maternal undernutrition during the last seven and last fourteen days of pregnancy on neurons of the rat coeliac-superior mesenteric ganglion has been investigated in neonates and in adult animals. The parameters studied were neuron diameter and the level of neuronal noradrenaline fluorescence. The morphology was more permanently affected by fourteen than by seven days undernutrition as shown by the smaller neuron diameters persisting at six months. Both periods of undernutrition affected noradrenaline levels permanently: seven days undernutrition producing a rise and fourteen days producing a depression. These changes demonstrate the permanent effects of maternal undernutrition on the development and maturation of prevertebral sympathetic neurons.

Two discrete enkephalinergic neuron systems in the superior cervical ganglion of the guinea pig: an immunoelectron microscopic study

Leucine-enkephalin (L-ENK)-like immunoreactive (L-ENKI) structures in the superior cervical ganglion (SCG) were first examined by using immunoelectron microscopy. L-ENKI neurons formed cell clusters and were small. They were filled with large granular or agranular vesicles and small electron lucent vesicles, and had nuclei that lacked a nucleolus. Since these morphological characteristics are identical to those of the small intensely fluorescent (SIF) cells, L-ENKI cells seemed to be a kind of SIF cell. Two types of L-ENKI fibers were identified, a large type filled with large granular or agranular vesicles and a small type filled with small electron lucent vesicles. The large fibers were located near the L-ENKI perikarya and often could be traced directly to the soma. These fibers remained intact after decentralization of the SCG. These findings indicate that the large L-ENKI fibers are processes of L-ENKI SIF cells. The fibers showed a close apposition to the blood vessels and rarely formed synaptic contact with dendrites of the principal cells. On the other hand, the small L-ENKI fibers were found to originate outside the SCG, because they disappeared after decentralization of the SCG. These L-ENKI fibers frequently formed synaptic contact with the dendrites of the principal cells. Thus, the present study demonstrated the presence of two discrete L-ENKI neuron systems in the SCG of the guinea pig, one an intrinsic SIF system and the other an extrinsic L-ENKI system.

Neurokinin A and galanin in the thyroid gland: neuronal localization

The distribution of neurokinin A (NKA) and galanin (GAL) in the thyroid gland of several species was examined with immunocytochemistry. NKA-immunoreactive fibers were observed around blood vessels and follicles in all species examined, whereas GAL-immunoreactive fibers were found in mice and rats only. NKA-containing fibers were more numerous than GAL-containing fibers. All thyroid NKA-containing fibers harbored substance P (SP), and the majority of them stored calcitonin gene-related peptide (CGRP) as well. Most thyroid GAL-immunoreactive fibers contained NKA, SP, and CGRP; in a minor population GAL coexisted instead with vasoactive intestinal peptide. Cervical vagotomy (extirpation of the nodose ganglion) reduced the number of NKA- and GAL-containing fibers in the thyroid by approximately 50%. The jugular ganglion and cervical dorsal root ganglia are fairly rich in GAL-, NKA/SP-, and CGRP-containing cell bodies, which presumably represent the source of GAL-, NKA/SP-, and CGRP-containing fibers in the thyroid. The thyroid ganglion is rich in vasoactive intestinal peptide nerve cell bodies, which presumably project to the thyroid gland; a minor proportion of these cell bodies was found to contain GAL as well. Although the distribution of NKA and GAL fibers in the thyroid suggests that the two peptides are involved in the regulation of local blood flow and follicular cell activity, neither NKA nor GAL had any influence on thyroid hormone release as tested in conscious mice.

Projections of bombesin-like immunoreactive fibers from the rat stomach to the celiac ganglion revealed by a double-labeling technique

Gastrofugal bombesin (BOM)-like immunoreactive (BOMI) structures in the rat were studied by immunocytochemistry combined with retrograde labeling. Transection of the mesenteric nerve peripheral to the celiac ganglion resulted in the complete disappearance of BOMI nerve terminals, whereas transection of the splanchnic nerves did not alter the immunoreactivity. Injection of biotinylated wheat germ agglutinin into the celiac ganglion labeled several neurons in the myenteric ganglion of the stomach. Simultaneous staining with antiserum against BOM showed that some of them are BOMI-positive. These findings demonstrate that BOMI neurons in the myenteric ganglion of the rat stomach project to the celiac ganglion.

Retrograde transport of endogenous nerve growth factor in superior cervical ganglion of adult rats

The concentration of naturally synthesized nerve growth factor (NGF) was measured in various tissues of adult rats, using a highly sensitive two-site enzyme immunoassay. The highest concentration was found in the superior cervical sympathetic ganglion (SCG). Transection of the postganglionic external carotid nerve (ECN) reduced the ganglionic level of NGF more than did section of the internal carotid nerve (ICN). When both the preganglionic nerve and the ECN were cut, the ganglionic NGF level decreased even more. On the other hand, when the preganglionic nerve and the ICN were both sectioned, leaving the ECN intact, endogenous NGF content in the SCG was significantly enhanced 3-9 h after operation. Bilateral extirpation of submaxillary gland produced a rapid decrease in ganglionic NGF 3-6 h after operation, and even unilateral removal of one salivary gland caused a decrease in both ganglia, which was however much greater in the ipsi- than in the contralateral ganglion. Removal of the eyeballs caused a much smaller reduction in ganglionic NGF than did removal of the glands. These results suggest that the endogenous NGF that accumulates in the SCG is mostly synthesized in the submaxillary gland rather than in the iris, and that it is transported to the SCG, mostly via the ipsilateral ECN.

Neurokinin A in capsaicin-sensitive neurons of the guinea-pig inferior mesenteric ganglia: an additional putative mediator for the non-cholinergic excitatory postsynaptic potential

The presence of neurokinin-A-like immunoreactivity in guinea-pig inferior mesenteric ganglia was detected by radioimmunoassay procedures. Pretreating the animals with capsaicin 7 days prior to experimentations reduced the mean content of neurokinin-A-like immunoreactivity by 85% from its control value of 150 +/- 31.3 fmol per ganglion. High-performance liquid chromatography revealed that neurokinin-A-like immunoreactivity was heterogenous as in addition to neurokinin A, peaks corresponding to the amphibian tachykinin eledoisin and to neuropeptide K were detected, and they too were depleted by capsaicin. Electrophysiological studies showed that neurokinin A applied either by superfusion or by pressure ejection evoked a slow depolarization in the majority of inferior mesenteric ganglia neurons in vitro. Neurokinin-A-evoked depolarizations in the majority of cells tested were associated with a small increase in membrane input resistance. However, the responses were increased by membrane hyperpolarization: the extrapolated mean equilibrium potential of neurokinin-A-induced depolarization was -36 mV. Removal of extracellular sodium but not chloride ions suppressed the neurokinin-A-induced depolarization. The slow depolarization elicited either by exogenously applied substance P or by repetitive stimulation of hypogastric nerves was reversibly eliminated in the presence of neurokinin A. Collectively, our studies suggest that neurokinin-A-like immunoreactivity may coexist with substance-P-like immunoreactivity in capsaicin-sensitive fibers in the guinea-pig prevertebral ganglia and that the similarity of the actions of neurokinin A on the one hand and substance P on the other raises the possibility that non-cholinergic excitatory potentials elicited in the inferior mesenteric ganglia may be generated by not one but a number of closely related tachykinins.

Atrial natriuretic polypeptide in spinal cord and autonomic ganglia

Using a radioimmunoassay for alpha-rat atrial natriuretic polypeptide (alpha-rANP), tissue levels of alpha-rANP-like immunoreactivity (-LI) in the rat spinal cord and autonomic ganglia were investigated. The alpha-rANP-LI level was higher in the more caudal parts of the spinal cord and the highest in the sacral spinal cord. alpha-rANP-LI was also detected in the superior cervical and coeliac ganglia. Gel permeation chromatographic analysis showed that the major peak of alpha-rANP-LI in the spinal cord was a low molecular weight form co-eluted with synthetic alpha-rANP. Reverse-phase high performance liquid chromatographic analysis revealed that alpha-rANP-LI with a low molecular weight in the spinal cord consisted of several components, two major components of which co-migrated with synthetic alpha-rANP (4-28) and alpha-rANP (5-28), whereas little immunoreactivity was eluted at the position of alpha-rANP. These findings suggest the involvement of ANP in the function of the spinal cord and autonomic nervous system.

Single cell quantitative immunocytochemistry of cyclic GMP in the superior cervical ganglion of the rat

In the superior cervical ganglion of the rat, using a newly developed antiserum against formaldehyde-fixed 3',5'-cyclic guanosine monophosphate (cGMP), cGMP immunoreactivity was observed in the large postganglionic neuronal cell bodies; no cGMP-immunofluorescence was found in nuclei or in satellite cells, glia or fibroblasts. In vitro incubation of ganglia in media with high K+ (up to 100 mM) or carbachol (10(-8)-10(-5) M) showed an increase only in cGMP-immunofluorescence in the large postganglionic cell bodies. The intensity of the immunofluorescence was taken as a measure for cGMP-immunoreactivity and was quantitated using a Leitz MPV-II system. Dose-response curves were constructed for the increase in cGMP-immunofluorescence intensity for K+ and carbachol. The carbachol stimulated cGMP-immunofluorescence intensity was antagonized competitively by atropine, whereas the high K+ stimulated cGMP-immunofluorescence intensity was not. Hexamethonium (10(-6) M) was without effect on the carbachol stimulated cGMP-immunofluorescence intensity. The morphological and pharmacological data indicate that we developed a very specific procedure for quantitative immunocytochemistry of cGMP in tissue sections. This technique makes it possible to use cGMP-immunofluorescence intensity as a postsynaptic parameter in individual cell bodies in heterogeneous tissue.

Insulin receptors in the peripheral nervous system: a structural and functional analysis

Although the brain is known to contain specific insulin receptors, there is no information on whether these receptors are also present in the peripheral nervous system (PNS). The present studies sought to provide this information by characterizing insulin binding in bovine autonomic (superior cervical) and sensory (trigeminal) ganglia. It was found that both ganglia contain specific, high-affinity receptors for insulin. Like insulin receptors in other tissue, these receptors could be solubilized and purified on wheat germ agarose columns and were found to have tyrosine-specific kinase activity. SDS-PAGE and autoradiography revealed that the apparent molecular weight (Mr) of the PNS insulin receptor was approximately 133 kDa which is similar to the Mr of hepatic receptors, but is approximately 10 kDa larger than the insulin receptor found in the brain. Because the vasculature of autonomic and sensory ganglia is fenestrated, it is possible that PNS insulin receptors are exposed to blood-borne insulin.

[Met5]enkephalin-Arg6-Phe7- and [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive nerve fibres and neurons in the superior cervical ganglion of the rat

[Met5]enkephalin-Arg6-Phe7-(MEAP-) and [Met5]enkephalin-Arg6-Gly7-Leu8-(MEAGL-) immunoreactivity was studied by indirect immunohistochemistry in the superior cervical ganglion of the rat with specific antisera produced in rabbits against the corresponding synthetic opioid peptides. Several MEAP- and a few MEAGL-immunoreactive principal nerve cells were observed in the ganglion, while the small intensely fluorescent cells appeared as non-reactive. The superior cervical ganglion also contained dense networks of MEAP- and MEAGL-immunoreactive nerve fibres, which often formed basket-like structures around the principal nerve cells and small intensely fluorescent cells. After ligation of the preganglionic nerve trunk with simultaneous transection of the main postganglionic trunks, a distinct accumulation of both MEAP- and MEAGL-immunoreactivity was observed on both sides of the ligature. Ligation of the preganglionic nerve trunk caused a marked decrease in the number of both MEAP- and MEAGL-immunoreactive nerve fibres in the ganglion. Ligation of the main postganglionic nerve trunks with simultaneous preganglionic nerve division resulted in accumulation of MEAP- and MEAGL-immunoreactive material on the ganglionic side of the ligature in both the external and internal carotid nerve. After division of both the pre- and postganglionic nerve trunks, some immunoreactive nerve fibres and principal nerve cells were still observed in the ganglion. A few immunoreactive neurons and nerve fibres were also observed in the ganglion stellatum. A large number of MEAP- and MEAGL-immunoreactive nerve fibres was detected in the spinal cord at the levels C6-Th6. A few neurons in the intermediolateral cell column of the spinal cord at levels C8-Th1 showed MEAP- but not MEAGL-immunoreactivity. The cultured superior cervical ganglion contained a few MEAP-immunoreactive neurons, and the fibre outgrowth showed immunoreactivity both to MEAP and MEAGL. In electron microscopy, MEAGL-immunoreactivity in the superior cervical ganglion was localized in nerve fibres containing neurotubules and in principal nerve cells. The present results demonstrate that the rat superior cervical ganglion contains both extrinsic and intrinsic MEAP- and MEAGL-immunoreactive nerve fibres. Most of these fibres are of preganglionic origin. Both the principal nerve and small intensely fluorescent cells are often surrounded by MEAP- or MEAGL-immunoreactive nerve fibres and may receive innervation by these fibres. Several ganglionic neurons projecting to the sympathetic target tissues show MEAP- and/or MEAGL-immunoreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitonin gene-related peptide-like immunoreactive sensory fibers form synaptic contact with sympathetic neurons in the rat celiac ganglion

The present study demonstrates synaptic contact between calcitonin gene-related peptide (CGRP)-like immunoreactive axon terminals and sympathetic neurons in the rat celiac ganglion. Our observations suggest that sensory ganglion neurons directly regulate the sympathetic activity via synapses, because CGRP immunoreactive (CGRPI) fibers in this ganglion are supplied by the sensory ganglia.