PubMed Health⌕ Search

Biomedical subjects

C J Dalsgaard

Publications and source records attributed to C J Dalsgaard.

At least 73 records · Page 4Linked to original sources

Effects of cysteamine on pain behaviour and on somatostatin- and substance P-like immunoreactivity in the substantia gelatinosa of the rat.

Immunohistochemical studies on rats showed cysteamine to deplete immunoreactive somatostatin, but not substance P, in the substantia gelatinosa of the spinal trigeminal nucleus and spinal cord. The effect of cysteamine treatment on chemical pain was investigated using capsaicin as the pain-producing stimulus. Thermal pain was assessed with a hot plate test after cysteamine treatment. It was found that cysteamine did not alter the hind paw lick latency in the hot plate test or the number of forepaw wipes after application of a drop of capsaicin into the cornea, compared to normal animals. In capsaicin-treated animals a significantly lower number of forepaw wipes were seen after corneal capsaicin application. However, in cysteamine-treated animals slower wiping was observed compared to untreated and capsaicin-treated animals. This suggests that somatostatin may be of importance for the modulation of nociceptive information, although it is not a major pain transmitter.

Animals↗

Invasion of lumbosacral ventral roots and spinal pia mater by substance P-immunoreactive axons after sciatic nerve lesion in kittens.

An indirect immunohistochemical technique was used to identify substance P immunoreactive nerve fibers in the ventral roots and spinal pia mater in kittens previously subjected to sciatic nerve lesion. It was shown that the ipsilateral L7 ventral root and spinal pia mater was invaded by substance P immunoreactive nerve fibers after the nerve lesion.

Animals↗

Electron microscopic and immunohistochemical evidence that unmyelinated ventral root axons make u-turns or enter the spinal pia mater.

The occurrence of unmyelinated and small myelinated axons and of nerve fibres with a substance P-like immunoreactivity was studied in juxtamedullary L7 ventral root fascicles and surrounding pia mater of kittens and cats. Electron microscopic analysis of thin transverse serial sections from this region in adult cats showed that the number of unmyelinated axon profiles decreases rapidly as the CNS is approached, reaching zero near or at the CNS/PNS border. No unmyelinated axons were found to enter the CNS through this root. At least to some extent, the disappearance of unmyelinated ventral root axons from the juxtamedullary root fascicles was due to presence of intrafascicular axonal hairpin loops and to a shift of axons from ventral root fascicles to the pia mater. It was also found that, in the L7 ventral root, the content of unmyelinated axons in the pia mater is lower in kittens than in cats. Fluorescence microscopic examination of specimens incubated with substance P antiserum showed that some looping axons and ventral root-pia mater axons were substance P immunoreactive. These observations suggest the hypothesis that sensory unmyelinated axons might grow through the L7 ventral root and enter the pia mater during postnatal development. Moreover they show that the occurrence of sensory unmyelinated axons in ventral roots does not necessarily contradict the law of Magendie .

Age Factors↗

Evidence for a spinal afferent innervation of the guinea pig lower respiratory tract as studied by the horseradish peroxidase technique.

The afferent innervation of the guinea pig lower respiratory tract was studied using a retrograde axonal transport technique with application of horseradish peroxidase (HRP) onto the lining respiratory epithelium. HRP-labeled cells were observed not only in the nodose ganglia but also in the jugular and upper thoracic dorsal root ganglia (mainly at the T2-T3 levels). Thus, both vagal parasympathetic and spinal sympathetic afferents seem to have peripheral branches close to or within the respiratory epithelium suggesting a dual sensory control of the airways.

Afferent Pathways↗

Distribution of neurofilament-immunoreactive nerve fibers in human skin.

Neurofilament immunoreactive nerve fibers were demonstrated in human skin using indirect immunohistochemical technique with antibodies to neurofilament polypeptides. Neurofilament-positive fibers were seen as free nerve endings in the epidermis and in dermal papilla, in Meissner's corpuscles and as fibers crossing in the dermis. Strongly fluorescent nerve fibers were also seen around hair follicles, sweat gland ducts and sometimes in relation to blood vessels. From the distribution pattern it was concluded that predominantly sensory nerve fibers were labelled and that this technique may be used to study reinnervation of cutaneous sensory nerves following traumatic injuries and surgical procedures.

Fluorescent Antibody Technique↗

Dynorphin-immunoreactive neurons in the autonomic nervous system.

The distribution of dynorphin-like immunoreactivity in the autonomic nervous system of the rat and guinea-pig was investigated using an antiserum raised against dynorphin-(1-17). Dynorphin-like immunoreactivity was observed in fiber networks in the prevertebral sympathetic ganglia, in fibers in the enteric plexa , circular muscle layer and a few in the lamina muscularis of the mucosa of the gastrointestinal tract. After colchicine treatment dynorphin-immunoreactive cell bodies were observed both in the myenteric and submucous ganglia of the gut. The paravertebral ganglia contained occasional dynorphin-positive fibers and a few immunoreactive small intensely fluorescent cells. The distribution of the dynorphin-like immunoreactivity was compared to the distribution of enkephalin-like immunoreactivity, and it was found that in some areas there were similarities in the distribution patterns, although in other areas there were clear differences, indicating a non-identity of these two systems.

Adrenal Glands↗

Separate origins for the dynorphin and enkephalin immunoreactive fibers in the inferior mesenteric ganglion of the guinea pig.

By different denervation procedures the origin of dynorphin-(1-17) and enkephalin immunoreactive fibers in the guinea pig inferior mesenteric ganglion was investigated. It was found that the dynorphin-(1-17)-positive fibers reached the ganglion predominantly via the colonic nerves and to a lesser extent via the hypogastric and intermesenteric nerves whereas the enkephalin-positive fibers reached the ganglion via the lumbar splanchnic nerves. These findings show that the dynorphin-(1-17) and enkephalin systems are separate in this ganglion.

Animals↗

Localization of substance P-immunoreactive nerve fibers in the human digital skin.

Substance P-immunoreactive nerve endings were localized in human digital skin by the use of indirect immunohistochemical technique. It was found that substance P-like immunoreactivity was present in free nerve endings in the dermal papillae and in the epidermis. Some Meissner's corpuscles also contained substance P positive nerve endings. Furthermore, substance P-immunoreactive nerves were localized in close connection to sweat gland ducts and blood vessels. The functional significance of these findings was discussed with regard to pain mediation and inflammatory response.

Fingers↗

Evidence of substance P immunoreactive neurons in dorsal root ganglia and vagal ganglia projecting to the guinea pig pylorus.

The origin of extrinsic substance P fibers in the guinea pig pyloric wall was investigated by combining retrograde axonal tracing and indirect immunofluorescence techniques. After injection of Fast Blue into the pyloric wall labeled cells were found in the T7-T9 dorsal root ganglia and the nodose and jugular ganglia. About 60% of the labeled cells in the dorsal root ganglia contained substance P-like immunoreactivity. After local application of colchicine, a few substance P positive cells were observed in the nodose and jugular ganglia, some of which also contained Fast Blue.

Animals↗

Enteric origin of bombesin immunoreactive fibres in the rat coeliac-superior mesenteric ganglion.

Bombesin-like immunoreactivity occurs in a dense network of nerve fibres in the rat coeliac-superior mesenteric ganglion. No bombesin immunoreactive cell bodies have been observed in this ganglion. An origin outside the ganglion was therefore assumed for the bombesin immunoreactive fibres. Ligation of the mesenteric nerve, between the ganglion and the gut resulted in an accumulation of bombesin immunoreactive material on the distal side, i.e. towards the gut. Transection of the nerve caused a depletion of bombesin immunoreactive fibres in the ganglion. These results suggest that bombesin immunoreactive fibres in the coeliac-superior mesenteric ganglion of the rat originate in neurons in the gastrointestinal wall. Application of colchicine to the stomach wall caused an accumulation of bombesin immunoreactive material in myenteric neurons.

Animals↗

Immunohistochemical indications of gastrin releasing peptide--bombesin-like immunoreactivity in the nervous system of the rat. Codistribution with substance P-like immunoreactive nerve terminal systems and coexistence with substance P-like immunoreactivity in dorsal root ganglion cell bodies.

Weak to strong gastrin releasing peptide--bombesin (GRP-Bn)-like immunoreactivity was found in fine varicose nerve terminal systems of low to high densities in several parts of the CNS. The highest densities of strongly immunoreactive terminals were found in the marginal layer and in the substantia gelatinosa of the spinal cord, and in parts of the nuc. tractus spinalis nervi trigemini. Morphometrical analysis in the spinal cord demonstrates that GRP-BN-like-immunoreactive and substance P (SP), but not somatostatin (SS)-immunoreactive nerve terminals strikingly codistribute. Coexistence of SP and GRP-BN-like immunoreactivities was demonstrated in trigeminal and spinal ganglion nerve cells. Thus, GRP-BN-like immunoreactivity may coexist with SP in certain SP-immunoreactive nerve terminal systems.

Animals↗

Capsaicin-induced depletion of substance P-like immunoreactivity in guinea pig sympathetic ganglia.

The distribution of substance P immunoreactive nerve fibers in guinea pig sympathetic ganglia was studied in normal and capsaicin-treated animals. A marked depletion of substance P-like immunoreactivity was observed in both pre- and paravertebral ganglia after capsaicin treatment. In the inferior mesenteric and pelvic ganglia, however, intensely fluorescent fibers surrounding some of the principal ganglion cells remain after capsaicin treatment. Ligation experiments on the inferior mesenteric ganglion indicate that the capsaicin-insensitive substance P immunoreactive fibers in this ganglion are of lumbar splanchnic origin. Whether or not they represent capsaicin-resistant primary afferent neurons is not known. The enkephalin, vasoactive intestinal polypeptide, cholecystokinin and bombesin immunoreactive fiber networks in the inferior mesenteric ganglion were also studied, and no differences were observed between normal and capsaicin-treated animals.

Animals↗

Origin of peptide-containing fibers in the inferior mesenteric ganglion of the guinea-pig: immunohistochemical studies with antisera to substance P, enkephalin, vasoactive intestinal polypeptide, cholecystokinin and bombesin.

After different denervation procedures the guinea-pig inferior mesenteric ganglion was analysed by immunohistochemistry using antisera to substance P, enkephalin, vasoactive intestinal polypeptide, cholecystokinin and bombesin. The results demonstrate that each of the nerve trunks connected to the ganglion carries specific peptidergic pathways. Thus, the lumbar nerves contain substance P-immunoreactive primary afferent neurons, which to a large extent traverse the ganglion, and enkephalin-immunoreactive preganglionic neurons; the colonic nerves carry vasoactive intestinal polypeptide-, cholecystokinin- and bombesin-immunoreactive fibers from the distal colon to the ganglion; the hypogastric nerves contain vasoactive intestinal polypeptide-positive fibers from the pelvic plexus; and the intermesenteric nerve contains vasoactive intestinal polypeptide, cholecystokinin, substance P and enkephalin from divergent sources. By studying accumulations of peptides in ligated lumbar splanchnic, intermesenteric, hypogastric and colonic nerves the existence of these major peptidergic pathways was confirmed and evidence was obtained for additional, not so prominent, peptidergic projections. The results arae discussed in view of earlier morphological and physiological studies.

Animals↗

Coexistence of cholecystokinin- and substance P-like peptides in neurons of the dorsal root ganglia of the rat.

Using the indirect immunohistochemical technique with antisera to cholecystokinin and to substance P, the spinal dorsal horn and dorsal root ganglia of normal and colchicine-treated rats were studied. In the spinal cord a similar distribution of substance P- and cholecystokinin-positive networks in the superficial layers of the dorsal horn was observed. In the dorsal root ganglia several cholecystokinin and substance P immunoreactive cell bodies were seen in colchicine-treated rats. After elution and restaining for substance P, of sections previously stained for cholecystokinin, it was found that all cholecystokinin-positive cells also contained substance P-like immunoreactivity and vice versa.

Animals↗

Distribution of substance P in brain and periphery and its possible role as a co-transmitter.

Substance P is widely distributed in the nervous system. In brain and spinal cord it may act as a transmitter, for example at the central branches of primary sensory neurons. It may also be released from the sensory nerve endings and is thought to be involved in antidromic vasodilatation and in synaptic transmission in autonomic ganglia. In some central neurons substance P is stored together with 5-hydroxytryptamine and thyrotropin-releasing hormone. These neurons project to the ventral horn of the spinal cord, amongst other places. In another system substance P coexists with a cholecystokinin-like peptide. These neurons are localized in the periaqueductal central grey matter and also project to the spinal cord. Finally, injection of a substance P antagonist into the ventral mesencephalon causes marked morphological changes in neurons that contain dopamine, substance P and gamma-aminobutyric acid (GABA).

Animals↗

Structural studies on the connectivity of the inferior mesenteric ganglion of the guinea pig.

After injection of horseradish peroxidase (HRP) into the inferior mesenteric ganglion (IMG) of the guinea pig, labeled cell bodies were found in the solar plexus ganglia, the ganglia of the pelvic plexus and in the nodose ganglia as well as in the spinal cord and dorsal root ganglia at the T13-L4 levels. By using the fluorescent tracer True blue, labeled cell bodies could also be detected in the myenteric and submucosa ganglia of the distal colon. Application and uptake of HRP by the colonic nerves resulted in labeling of cell bodies in the dorsal root ganglia, the IMG and in the solar plexus ganglion complex indicating that the latter neurons send their axons in the intermesenteric nerve through the IMG to continue in the colonic nerves to the distal colon. When HRP was applied and diffused into the hypogastric nerves labeled cell bodies were seen in the IMG, the dorsal root ganglia and in the preganglionic nuclei of the lumbar spinal cord with 50% of the labeled neurons located dorsal and dorsolateral to the central canal. The finding of such a diversity in the nerve supply to the IMG, supports the view that the ganglion plays an important role in the integration of visceral reflexes.

Animals↗