Search results for "Cervical ganglia"
showing 7 items of 7 documents
Effects of electrical stimulation of the superior cervical ganglia on the number of ?synaptic? ribbons and the activity of melatonin-forming enzymes …
1989
Melatonin metabolism in the mammalian pineal gland is under the clear influence of sympathetic fibers originating in the superior cervical ganglia (SCG). Previous studies suggested that pineal "synaptic" ribbons (SR) as well are regulated by the gland's sympathetic innervation. To gain more insight into the mechanisms involved, we examined the effects of sympathetic stimulation on SR number and on the activity of melatonin forming enzymes, serotonin N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT). The SCG in adult male rats were stimulated electrically during daytime for either 15 or 120 min. Immediately following stimulation, the glands were removed and processed fo…
Calcitonin gene-related peptide-like immunoreactivity in spinal cord and superior cervical ganglion of the djungarian hamster (Phodopus sungorus)
1993
The indirect immunofluorescent method was employed to investigate the distribution of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the spinal cord and superior cervical ganglion of the Djungarian hamster Phodopus sungorus. In cross-sections of the spinal cord, immunoreactive fibres and terminals were found in laminae 1 and 2 in high density, in the dorsolateral (Lissauer's) tract, in ventral and lateral horns, and in the area surrounding the central canal. A few CGRP-LI perikarya were seen in the ventral but not the dorsal horn. CGRP-LI was further observed in preganglionic sympathetic neurons which were labelled by retrograde axonal transport of fluoro-gold (FG) follo…
Nitric oxide synthase-immunoreactive vagal afferent fibers in rat superior cervical ganglia
1995
Abstract Chronic (5–14 days) preganglionic denervation of the rat superior cervical ganglia by sectioning the cervical sympathetic trunk resulted in a time-related partial or complete loss of nitric oxide synthase (isoform I)-immunoreactive fibers and terminals surrounding many sympathetic ganglionic neurons. Unexpectedly, denervation unmasked many varicose nitric oxide synthase-immunoreactive fibers, some of which could be traced the entire length of the superior cervical ganglia. Injection of the retrograde tracer Fluorogold into the superior cervical ganglia labeled a population of nodose ganglion cells and of dorsal root ganglion cells from C8 to T3 segments. When the same sections were…
Spinal relay neurons for central control of autonomic pathways in a photoperiodic rodent.
2021
Location and distribution of spinal sympathetic preganglionic neurons projecting to the superior cervical ganglion were investigated in a rodent model organism for photoperiodic regulation, the Djungarian hamster (Phodopus sungorus). Upon unilateral injection of Fluoro-Gold into the superior cervical ganglia, retrograde neuronal tracing demonstrated labeled neurons ipsilateral to the injection site. They were seen in spinal segments C8 to Th5 of which the segments Th1 to Th3 contained about 98% of the labeled cells. Neurons were found in the spinal cord predominantly in the intermediolateral nucleus pars principalis and pars funicularis. At the same time, the central autonomic area and the …
Distribution of dopamine-beta-hydroxylase—like immunoreactivity in the rat pineal organ
1985
The aim of the present investigation was to study the distribution in the rat pineal gland of dopamine-beta-hydroxylase (DBH) which is essential for the formation of the melatonin synthesis-regulating substance noradrenaline (NA). In 5- and 8-month-old male Sprague-Dawley rats DBH-like immunoreactivity (DBH-LI) was studied using polyclonal antibodies against DBH and the indirect immunofluorescent technique. DBH-LI was mainly located in pineal nerve fibres coming from the superior cervical ganglia. The intensity of the staining reaction was considerably lower than in non-pineal noradrenergic nerve fibres and the impression was gained by comparison of DBH-LI specimens with glyoxylic acid-trea…
Principal neurons projecting to the pineal gland in close association with small intensely fluorescent cells in the superior cervical ganglion of rats
1988
The localization in the superior cervical ganglia (SCG) of small, intensely fluorescent (SIF) cells and of principal nerve (PN) cells innervating the pineal gland was examined in adult male Sprague-Dawley rats. PN cells were demonstrated by means of the retrograde neuron-tracing method using the fluorescent tracer Fluoro-Gold (FG) injected into the pineal gland. SIF cells were visualized by the formaldehyde-induced fluorescence method. Twenty-nine percent of the FG-labeled PN cells were found closely associated with SIF cells. In the rostral half of the ganglion, 43% of the SIF cells were situated in juxtaposition to one or several labeled neurons. The possible influence of SIF cells on the…
Pineal 'synaptic' ribbons in sympathectomized rats.
1989
The melatonin metabolism in the mammalian pineal gland is under the clear influence of sympathetic fibers originating in the superior cervical ganglia (SCG). Previous studies suggested that also pineal ‘synaptic’ ribbons (SR) are regulated by the gland’s sympathetic innervation. To gain more insight into the mechanisms involved SR numbers were determined in adult rats which were chemically sympathectomized as newborns by injection of 6-hydroxydopamine (6-OHDA). In control animals (saline injections), a clear day/night difference in the number of SR is present. In sympathectomized animals SR are higher in number throughout the 24-hour cycle but are not significantly elevated at night. The pr…