The fine structure of thoracic sympathetic neurons in the adult rat

1966 ◽  
Vol 71 (2) ◽  
pp. 189-206 ◽  
Author(s):  
Carmen Lemos ◽  
Joseph Pick
Keyword(s):  
Fine Structure ◽  
Sympathetic Neurons ◽  
Adult Rat

The fine structure of sympathetic neurons in man

1964 ◽  
Vol 122 (1) ◽  
pp. 19-67 ◽  
Author(s):  
Joseph Pick ◽  
Carmen De Lemos ◽  
Carin Gerdin
Keyword(s):  
Fine Structure ◽  
Sympathetic Neurons

Maturation and Fine Structure of Thalamic Reticular Neurons Transplanted into the Adult Rat CNS

1992 ◽  
Vol 14 (2) ◽  
pp. 130-143 ◽  
Author(s):  
Brigitte Onténiente ◽  
Fatiha Nothias ◽  
Michel Geffard ◽  
Marc Peschanski
Keyword(s):  
Fine Structure ◽  
Adult Rat ◽  
Reticular Neurons ◽  
Rat Cns

Growth and fine structure of monolayers derived from adult rat adenohypophyseal cell suspensions

In Vitro ◽  
1973 ◽  
Vol 8 (4) ◽  
pp. 301-306 ◽  
Author(s):  
G. Rappay ◽  
Angéla Gyévai ◽  
L. Kondics ◽  
E. Stark
Keyword(s):  
Fine Structure ◽  
Cell Suspensions ◽  
Adult Rat ◽  
Adenohypophyseal Cell

Effects of Buthus martensii Karsch scorpion venom on the release of noradrenaline from in vitro and in vivo rat preparations

1994 ◽  
Vol 72 (8) ◽  
pp. 855-861 ◽  
Author(s):  
Sylvain Foucart ◽  
Rui Wang ◽  
Pierre Moreau ◽  
Rémi Sauvé ◽  
Jacques de Champlain ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Noradrenaline Release ◽  
Sympathetic Neurons ◽  
Scorpion Venom ◽  
Dependent Manner ◽  
Release Of Noradrenaline ◽  
Adult Rat ◽  
Isolated Atria

The aim of this study was to test the neuronal effects of the Chinese Buthus martensii Karsch (BMK) scorpion venom in vivo and in vitro in order to understand the mechanism involved in the cardiovascular pressor effect of this venom. In conscious unrestrained rats, administration of 100 μg/kg i.v. BMK venom induced an increase in blood pressure, which was associated with a significant increase in plasma noradrenaline. In isolated atria, BMK also induced an increase in the stimulation-induced release of [3H]noradrenaline in a dose-dependent manner. The modulatory effect of agents acting at sympathetic prejunctional adrenoceptors on [3H]noradrenaline release was not altered by BMK venom administration. Finally, it was observed that 100 μg/mL BMK venom increased the intracellular calcium concentration in acutely dissociated sympathetic neurons from adult rat superior cervical ganglion. This action appeared to be mainly due to an influx of extracellular calcium. BMK venom induced a small rise in intracellular calcium in the absence of external calcium, indicating that it may also mobilize calcium from intracellular stores. The results observed in this study suggest that BMK venom may induce pressor responses by releasing noradrenaline from the sympathetic nerve terminals and that activation of neuronal calcium channels may be involved in that process.Key words: scorpion venom, noradrenaline release, presynaptic modulation, intracellular calcium.

Pancreatic polypeptide inhibits calcium channels in rat sympathetic neurons via two signaling pathways

1995 ◽  
Vol 73 (3) ◽  
pp. 1323-1328 ◽  
Author(s):  
L. P. Wollmuth ◽  
M. S. Shapiro ◽  
B. Hille
Keyword(s):  
G Protein ◽  
Pertussis Toxin ◽  
Pancreatic Polypeptide ◽  
Sympathetic Neurons ◽  
Whole Cell ◽  
Adult Rat ◽  
Voltage Dependent ◽  
Cervical Ganglion ◽  
Gamma S ◽  
Ca2 Channels

1. We studied modulation of N-type Ca2+ channels in adult rat superior cervical ganglion (SCG) neurons by pancreatic polypeptide (PP) using whole cell clamp. In large (> 20 pF) SCG neurons, PP inhibited ICa (35 +/- 2%, mean +/- SE) in a concentration-dependent fashion, with one-half maximal inhibition at 19 nM. 2. One-third of the inhibition was blocked by pertussis toxin, about one-half was blocked by N-ethylmaleimide (NEM) treatments, and about one-half was voltage dependent. The NEM-insensitive component of the PP inhibition was voltage independent and not significantly blocked by intracellular Ca2+ chelators. 3. The NEM-insensitive component was only weakly attenuated by GDP-beta-S, and moderately reversible with guanosine 5'-triphosphate (GTP)-gamma-S, in the whole cell pipette, leaving open the possibility that it is not mediated by a G protein. 4. Hence, PP inhibits ICa via two mechanisms: one G-protein-mediated and the other possibly G-protein independent. The former pathway is sensitive to pertussis toxin (PTX) and NEM, voltage dependent, and shared by several other transmitters in these cells. The latter pathway is PTX-and NEM-insensitive, not voltage dependent, and not affected by the presence of intracellular Ca2+ chelators.

Multiple mechanisms regulate sympathetic neuronal phenotype

Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2361-2371
Author(s):  
A.K. Hall ◽  
S.E. MacPhedran
Keyword(s):  
Sympathetic Neurons ◽  
Intrinsic Property ◽  
Sympathetic Ganglia ◽  
Environmental Cues ◽  
Peripheral Target ◽  
Neuronal Phenotype ◽  
Adult Rat ◽  
Cervical Ganglion

Adult rat sympathetic neurons can possess specific neuropeptides utilized as cotransmitters along with norepinephrine, but the factors that regulate their expression remain unknown. 60% of adult rat superior cervical ganglion (SCG) neurons express neuropeptide Y (NPY) in vivo. To determine whether the restricted expression was an intrinsic property of sympathetic ganglia, we examined if embryonic sympathetic precursors gave rise to NPY immunoreactive (-IR) neurons in vitro. After one week in culture, 60% of neurons derived from the E14.5 rat SCG were NPY-IR. Thus, ganglia isolated before peripheral target contact or preganglionic innervation were capable of regulating NPY expression both in the number of neurons with NPY and in the developmental timing of NPY expression. To determine if the restricted expression of NPY was a reflection of neuroblasts committed to an NPY fate, SCG precursors were labeled with a replication incompetent retrovirus carrying lacZ, and NPY expression in lacZ-labeled clones examined after one week. Two thirds of neuronal clones obtained were uniformly NPY-IR; that is, all neurons in a clone either possessed or lacked NPY. One-third of the neuronal clones were mixed and contained both neurons with and without NPY. We provide a novel demonstration that both lineage and environmental cues contribute to neuropeptide phenotype.

scholarly journals THE FINE STRUCTURE OF SYMPATHETIC NEURONS IN X-IRRADIATED FROGS

1965 ◽  
Vol 26 (2) ◽  
pp. 335-351 ◽  
Author(s):  
Joseph Pick
Keyword(s):  
Fine Structure ◽  
Sympathetic Neurons ◽  
Sympathetic Ganglia ◽  
Nerve Fibers ◽  
Whole Body ◽  
Complete Fusion ◽  
Unmyelinated Fibers ◽  
Standard Procedures ◽  
Myelinated And Unmyelinated Fibers ◽  
X Irradiation

The effects of whole body x-irradiation on the fine structure of sympathetic neurons were studied in 15 unanesthetized adult frogs (Rana pipiens), as seen at intervals ranging from 1 hour to 2 weeks after single exposures to 1000 r and 2000 r. Using standard procedures, the lumbar sympathetic ganglia of experimental and 20 control animals were prepared for electron microscope examination. Radiation produced conspicuous but irregular and variable deterioration, swelling, and clearing of neuronal lysosomes. These changes may have been due to an increased permeability of lysosomal membranes, causing the entry of fluid into lysosomes and their swelling and deterioration, but a pronounced escape of lysosomal enzymes into the cytoplasm was questionable. Less frequent were the dilatation and the parallel layering or complete fusion and tight packing of the rough-edged endoplasmic reticulum. The number of vacuoles, probably derived from Golgi cisternae, was somewhat increased. These vacuoles were conjectured to serve the "sequestration" of damaged cytoplasmic areas. Abnormal amounts of presumptive glycogen granules occupied some axons of myelinated and unmyelinated fibers, especially of presynaptic nerve fibers. This was assumed to be due to a decreased breakdown of glycogen and probably caused the interruption of the transmission of nerve impulses in presynaptic fibers. The maximal incidence of these alterations seemingly occurred 8 days after exposure to 1000 r, and 1 hour after x-irradiation with 2000 r. Signs of recovery appeared 2 weeks after exposure to 2000 r.

Modulation of Ca(2+)-channel currents by protein kinase C in adult rat sympathetic neurons

1994 ◽  
Vol 72 (4) ◽  
pp. 1549-1560 ◽  
Author(s):  
Y. Zhu ◽  
S. R. Ikeda
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
G Protein ◽  
G Proteins ◽  
Sympathetic Neurons ◽  
Adult Rat ◽  
Kinase C ◽  
Channel Inhibition ◽  
Channel Currents ◽  
Ca2 Channels

1. Modulation of Ca(2+)-channel currents by phorbol-12-myristate-13-acetate (PMA) was investigated in acutely dissociated adult rat superior cervical ganglion neurons using the whole cell variant of the patch-clamp technique. 2. PMA (500 nM) increased the current amplitudes, accelerated the inactivation of step currents, retarded the deactivation of tail currents, and shifted the tail current activation to more negative potentials. 3. The effects of PMA were concentration and voltage dependent and mediated through activation of protein kinase C (PKC). PMA also increased Ca2+ currents recorded with the perforated patch technique. 4. PMA affected the N-type Ca2+ channels and an omega-conotoxin GVIA-resistant current component. Ca2+ currents affected by PMA were not sensitive to omega-agatoxin IVA or nimodipine. 5. PMA not only attenuated Ca(2+)-channel inhibition induced by alpha 2-adrenoceptor agonist, which modulates Ca2+ channels via a pertussis toxin (PTX)-sensitive pathway, but also attenuated current inhibition by vasoactive intestinal polypeptide, which modulates Ca2+ channels via a PTX-insensitive but cholera toxin-sensitive pathway. 6. PMA reversed Ca(2+)-channel inhibition induced by tonic activation of G-protein in the absence of neurotransmitter (even in neurons pretreated with PTX) or induced by activation of G-proteins with guanosine 5'-O-(3-thiotriphosphate) (GTP)-gamma-S. 7. Inhibition of phosphatase by okadaic acid or substitution of Ba2+ for Ca2+ in the external solutions accelerated the PMA effect. 8. Our results suggest that activation of PKC antagonizes G-protein mediated inhibition of Ca2+ channels by shifting Ca2+ channels from the “reluctant” state to the “willing” state. The G-proteins and, more likely, the N-type Ca2+ channels may be the target of PKC phosphorylation. Protein phosphatases may be involved in counteracting the PKC phosphorylation in rat sympathetic neurons.

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