Catecholaminergic Nerve Fibers Research Articles

Immunoelectron microscopic study of tyrosine hydroxylase immunoreactive nerve fibers and ganglion cells in the rat adrenal gland

The present immunocytochemical study used an antiserum to tyrosine hydroxylase (TH), the first enzyme in the biosynthetic pathway of catecholamines, and revealed TH immunoreactivity in the ganglion cells and in the varicose nerve fibers of the cortex and medulla in the rat adrenal gland. TH immunoreactive nerve fibers in the cortex and medulla contained large and small granular vesicles, and also small clear vesicles. The immunoreactive nerve fibers were in close apposition to cortical cells in the cortex and in apposition to smooth muscle cells of blood vessels in both the cortex and medulla. Furthermore, TH immunoreactive nerve fibers were sometimes in close apposition to pericytes of blood vessels in the cortex and chromaffin cells in the medulla. The present results suggest that the catecholaminergic nerve fibers in the rat adrenal gland may be both intrinsic and extrinsic in origin.

Sympathetic Innervation of Normal and Rheumatoid Synovial Tissue

Fresh synovial tissue was taken from two normal subjects and five patients with rheumatoid arthritis, and treated so that catecholaminergic sympathetic nerve fibres could be seen. A fluorescent network of varicose fibres was visible in normal as well as in rheumatoid synovial tissue. In the rheumatoid inflammatory tissue an increased number of fluorescent sympathetic nerve fibres could be seen in close proximity to blood vessels, even in the smallest synovial plica, indicating that the proliferation of inflammatory vessels is accompanied by simultaneous sympathetic nerve proliferation. A nervous component might thus contribute to the inflammatory process in human rheumatoid arthritis.

Histochemistry and infrastructure of Nerve Fibres and Contractile Cells in the Tunica albuginea of the Rat Testis

Whole-mounted preparations of the tunica albuginea of the rat testis were studied using light microscopy techniques for demonstration of cholinergic nerve fibres (Karnovski-Root method), catecholaminergic nerve fibres (De la Torre's method) and actin filaments (avidin-biotin-peroxidase method). An ultrastructural study of different regions of the albuginea was also performed. Cholinergic fibres were seen to penetrate into the albuginea with the testicular artery to form a broad network in the mediastinum testis, many fibres ending beneath the rete testis epithelium. Catecholaminergic fibres penetrated through the middle part of the cauda epididymis and formed a plexus in the albuginea covering the inferior testicular pole. This plexus gave rise to straight fibres which formed varicosities, some of them appeared related with mast cells. Actin-containing cells were only found beneath the rete testis epithelium. These cells were similar to myofibroblasts. The location of both cholinergic fibres and contractile cells among the rete testis channels suggests that these cells may be involved in the pumping of semen towards the ductuli efferentes and that their contractility may be regulated by cholinergic fibres.

The vascular and epithelial serotonergic innervation of the actinopterygian gill filament with special reference to the trout, Salmo gairdneri

Antibodies against serotonin and 5-methoxytryptamine reveal indolaminergic neurons innervating the proximal part of the efferent arterial vasculature, the filament epithelia, the central venous sinus, and certain other serotonergic cells of the teleost gill filament. In the same area, acetylcholinesterase-positive and indoleaminergic neurons have already been described. We propose that these populations of neurons belong to a single neuronal type but express different agents. Our current results support this idea; in particular, they point to the presence of a single type of serotonin-containing nerve terminal, impinging on vascular smooth muscle. These results are in agreement with physiological data showing (i) the existence of non-cholinergic (atropine-resistant) vasoconstriction of the gill vasculature after nerve stimulation, and (ii) a potent vasoconstrictory action of infused serotonin. In addition, the above-mentioned serotonergic neurons have synaptic contacts with catecholaminergic nerve fibers, suggesting the existence of a modulatory relationship between the sympathetic and the cranial autonomic nerves supplying the teleost gill. Finally, these neurons show morphological relationships with a previously undescribed type of branchialserotonergic cell. The role of the parasympathetic nerve plexus of the teleost gill filament in the control of respiration and ionoregulation is discussed.

Tyrosine-Hydroxylase-Immunoreactive Nerve Fibers in the Separated Capsule of the Rat Adrenal Gland

The present study applied the separated adrenal capsules of rats for wholemount immunocytochemistry and used tyrosine hydroxylase (TH) antibody as a marker for catecholamines. TH-immunoreactive nerve bundles without varicosities and fibers with varicosities were seen to run along or to encircle blood vessels entering the adrenal capsule from the outside, and then to run along a network of blood vessels in the intracapsular region. Also, the TH-immunoreactive nerve bundles and fibers were found to run along blood vessels in the subcapsular region. Some TH-immunoreactive nerve fibers and bundles with varicosities, unassociated with the blood vessels, were seen in the subcapsular region. In this region, TH-immunoreactive nerve fibers with varicosities were often seen to be closely associated with the cortical cells. Some TH-immunoreactive nerve fibers without varicosities were visible within the splanchnic nerve in the subcapsular region. The present study suggests that numerous catecholaminergic nerve fibers are associated with blood vessels forming a network in the superficial region of the rat adrenal gland.

Catecholaminergic nerves in the embryonic chick ovary: co-localization with beta 2-adrenoceptor-bearing steroidogenic cells.

The present study investigates the innervation of the embryonic chick ovary with regard to (i) development and compartmentalization of catecholaminergic nerves, and (ii) presence of adrenoceptors on steroidogenic target cells of catecholaminergic nerve terminals. Catecholaminergic nerve fibers visualized by glyoxylic acid-induced histofluorescence first appeared at embryonic day (E) 13. From E15 through E21 the density of fluorescent aminergic nerves increased markedly in parallel with the concentration of catecholamines and numbers of nerve bundles and single axons seen at the electron-microscopic level. Catecholaminergic nerves were confined to the ovarian medulla and closely associated with interstitial cells. Nerve terminals approached interstitial cells up to a distance of 20 nm and, in their majority, exhibited uptake of the false adrenergic transmitter 5-hydroxydopamine. Although adrenaline amounted to 14% of the total catecholamine content at E21, adrenaline immunoreactivity was only detected in adrenal chromaffin cells, but not in nerve fibers or cell bodies within the ovary. Interstitial cells structurally matured between E15 and E21 as documented by an increase of smooth endoplasmic reticulum and tubular mitochondria. Monoclonal antibodies mAB 120 and BRK 2 raised against avian beta 1- and mammalian beta 2-adrenergic receptors revealed the presence of beta 2-adrenoceptor-like immunoreactivity on the surface of interstitial cells, but not on any other cell type. The results are consistent with the notion of a dense adrenergic innervation of the embryonic chick ovarian medulla and its steroidogenic interstitial cells, and suggest the chick ovary as an excellent model for elucidating the functional role of a neural input to steroidogenic cells during development.

分化した単発性グロムス腫ようにおける交感神経の分布

分化した単発性グロムス腫ようにおける交感神経の分布

The innervation of intraocular spinal cord transplants by cografts of locus ceruleus and substantia nigra neurons

The nucleus locus ceruleus and the substantia nigra were sequentially cografted with spinal cord in the anterior chamber of the eye of adult rats. The double grafts were allowed to mature in oculo. After a survival time of 2 months, half of the number of rats were sacrificed, the grafts were dissected out and prepared for tyrosine hydroxylase immunohistochemistry and Falck-Hillarp monoamine histochemistry. The remaining animals were sacrificed after 12–14 months and processed according to the same protocol. No ingrowth from the sympathetic ground plexus in the host iris was seen in single spinal cord grafts at any of the survival times. At the shorter survival time there were no or very few catecholaminergic nerve fibers from the locus ceruleus or substantia nigra that were innervating the spinal cord cograft. In double grafts that were allowed to remain in oculo for 12–14 months, the entire spinal cord graft was innervated with varicose, catecholamine-containing nerve fibers. The locus grafts were able to innervate the spinal cord cografts much more densely than the substantia nigra grafts. In conclusion, the results demonstrate that isolated intraocular spinal cord grafts can be innervated by adjacent central catecholamine neurons. However, this is done in a delayed manner as compared to other models. The isolated replicas of descending adrenergic pathways to the spinal cord thus formed should provide useful information about the function of descending spinal catecholamine pathways.

Blood-brain barrier leakage and brain edema in stroke-prone spontaneously hypertensive rats. Effect of chronic sympathectomy and low protein/high salt diet.

Brain edema associated with severe chronic hypertension was studied in stroke-prone spontaneously hypertensive rats (SHRSP), 5 to 9 months of age. Blood-brain barrier (BBB) leakage sites and intracerebral spreading pathways for plasma proteins were delineated by an intravenously (i.v.) injected exogenous dye tracer (Evans blue), known to form a complex with albumin in blood, and by immunohistochemical visualization of extravasated endogenous plasma proteins. The tissue content of edema fluid was estimated by measuring the specific gravity of selected brain regions, stained or unstained by the tracer dye, on a bromobenzene-kerosene gradient column. Multifocal BBB leakage sites were macroscopically detected within the cerebral cortex and the deep gray matter after i.v. circulation of Evans blue-albumin for 30 min. After 24 h of i.v. circulation the dye tracer had spread not only locally in the gray matter but also into the adjacent white matter, where it was widely distributed. Immunohistochemically visualized plasma proteins showed similar distribution. Unilateral superior cervical ganglionectomy performed at 4 weeks of age neither increased the incidence of major BBB opening to Evans blue-albumin nor altered the specific gravity of the ipsilateral cerebral hemisphere in grown-up SHRSP, furthermore, the blood pressure remained unchanged. The lack of significant effect on BBB function may possibly be attributed to the extensive reinnervation of the cerebral arteries, verified in the grown-up SHRSP using the Falck-Hillarp fluorescence method for visualization of catecholaminergic nerve fibers. In SHRSP raised on a low-protein and high-salt diet the mean arterial blood pressure was 212 mm Hg compared to 195 mm Hg in controls (P less than 0.05) and the incidence of BBB opening was 72% compared to 25% in controls (P less than 0.05). After 24 h of i.v. circulation of Evans blue-albumin, brain regions stained by the dye tracer showed significantly reduced specific gravity (P less than 0.001), while unstained regions had normal values. Thus the brain edema fluid spread, as revealed by specific gravity measurements, corresponded to the intracerebral distribution of extravasated plasma proteins.

Fine structure of peptidergic and catecholaminergic nerve fibers in the anterior cerebral artery and their interrelationship: an immunoelectron microscopic study.

This study shows (1) the ultrastructure of vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and neuropeptide Y (NPY)-containing nerve fibers in the walls of the cerebral arteries and (2) the relationship between these peptidergic (VIP, SP, and NPY) and catecholaminergic (CA) nerve terminals by immunohistochemistry combined with false transmitter (5-hydroxydopamine) histochemistry under the electron microscope. VIP-, SP-, and NPY-like immunoreactivity (VIPI, SPI, and NPYI) were found diffusely in the axoplasm and around the small clear vesicles in the nerve terminals. In a few cases, SPI was found within the large vesicles. Most of the VIPI terminals were ensheathed by the cytoplasm of the Schwann cells together with CA terminals, identified as those with a number of small granulated vesicles. In some cases, they were directly apposed to the smooth muscle cells at a distance of about 100 nm. SPI terminals were frequently solitary but about 30% were located together with CA and other (neither SPI nor CA) terminals ensheathed by Schwann cells, directly apposed to the smooth muscle cells at a distance of about 100 nm. On the other hand, NPYI terminals were also identified as CA terminals, indicating the coexistence of these two substances. These findings suggest a close interrelationship between peptidergic and CA nerve terminals in the neurogenic control of cerebral blood vessel function.

The Regeneration of Substance P-Containing Nerve Fibers in the Process of Burn Wound Healing in the Guinea Pig Skin

The regeneration of substance P (SP)-containing nerve fibers in the process of burn wound healing in the guinea pig skin has been studied by immunohistochemistry. SP-like immunoreactivity, which was specifically localized in neural elements of intact skin, was found to disappear in the burn wound including its margin on day 2 post burn. The SP-containing nerve fibers were first detected in periods later than day 2 post burn, and the regeneration seemed to occur in association with regeneration of blood vessels at the wound margins. These nerve fibers gradually increased in number and acquired maximum density on day 14 post burn. In addition, such renewed fibers showed sprouting to form a dense network, which has never been observed in intact skin, in the upper granulation tissue just beneath the regrowing epidermis. Following that peak period, the density of the fibers gradually decreased to less than that of controls. The characteristic process of regeneration of SP-containing nerve fibers, having a peak period of fiber density at least in burn wound healing, appeared similar to that of the regeneration of sympathetic catecholaminergic nerve fibers reported previously.

Healing and catecholaminergic nerve fibres

Healing and catecholaminergic nerve fibres

The Regeneration of the Sympathetic Catecholaminergic Nerve Fibers in the Process of Burn Wound Healing in Guinea Pigs

In the present study, morphological alterations of cutaneous catecholaminergic nerve fibers in the process of burn wound healing have been investigated by using glyoxylic acid induced fluorescence histochemistry. The sympathetic denervation is detected within 48 hr after burns as well as in various excisions. The regenerating sympathetic fibers are observed on the 7th day after burns. These regenerating fluorescent fibers seem to develop in accordance with the regeneration of blood vessels in the wound margins at various stages of healing. Regenerating sympathetic fibers gradually increase in number and the maximum density of these fibers is found approximately at 2 weeks after burns. Thereafter, the density of the fibers gradually decreases to less than that of sympathetic innervation of intact skin. On the 14th day after burns, dense regenerating fibers are observed around the regenerated arterial vessels in the deep granulation tissue of the wound margins. These fibers may correlate with the degeneration of regenerated blood vessels in the center of the wound because of contracting the blood vessel of the wound margins. Moreover, dense collateral sprouting of regenerating fibers is observed around the degenerative blood vessel in the center of the wound on the 16 day after burns. This sprouting occurs not because of searching after a new target organ following the degeneration of the target organ but because of playing important roles in certain functions during wound healing.

Histofluorescence analysis of several systems of catecholaminergic nerve fibres within the rat neostriatum revealed by either restricted lesions of the substantia nigra or γ-hydroxybutyrate

The glyoxylic acid fluorescence technique was applied to the study of catecholamine fibres in the caudate-putamen (neostriatum) of control and experimental adult rats. Cryostat or vibratome sectioning procedures were used; in the last case, either incubations of brain slices in γ-methyl-noradrenaline or pre-treatment of animals with γ-hydroxybutyrate were performed, in order to increase the intensity of fluorescence. In control animals and in the contralateral side of rats lesioned in the substantia nigra, the fluorescence of the dense plexus of dopamine nerver fibres appeared under the form of densely packed varicosities. However, some regions differed from the ordinary fluorescence of the neostriatum by their stronger intensity and more visible varicosities. They were located principally in the ventro-medial regions bordering either the nucleus accumbens, the dorsal nucleus interstitialis striae terminalis and the ventricle in the anterior part, or the amygdala, the globus pallidus and the ventricle in the posterior part. Moreover, islands of stronger fluorescence also were observed in the head of the caudate-putamen along the dorsal and lateral corpus callosum, as well as scattered in the central region. These particular neostriatal structures might correspond to a separate system of ascending dopamine nerve fibres. Therefore, restricted electrolytic lesions of the substantia nigra pars compacta were undertaken in order to study the morphology of the remaining Catecholaminergic fibres in the ipsilateral neostriatum. In largely denervated areas, different types of fluorescent axons were evident. Presumed noradrenergic nerve fibres characterized by a very coarse appearance and closed varicosities were rare. They contrasted markedly with numerous delicate fibres which might belong to several dopaminergic systems. Both first types exhibited long, clearly visible intervaricose segments and ovoid triangular varicosities. The second type, which was thicker and more strongly fluorescent, probably formed the islands observed in unlesioned striata. The third type had very closed, small spherical varicosities and poorly fluorescent intervaricose segments. Dopamine nerve fibres of the same morphology were described previously in the neocortex [43,44] and the possibility of a common origin for nerve fibres of the same type is discussed. When rats were treated with the anaesthetic γ-hydroxybutyrate, all the dopamine nerve fibres appeared to develop a strong fluorescence within the neostriatum, but more fluorescent islands were always visible. Additionally, some swollen fluorescent fibres were seen; these could be abnormal dopamine fibres whose metabolism had been pathologically altered by the drug.

Mechanisms for induction of drinking with special reference to angiotensin II

The Japanese quail drinks water vigorously after water deprivation, haemorrhage and administration of hypertonic saline solution. Most avian species responded to angiotensin II (AII) by drinking, but carnivorous birds and those originating in arid regions were insensitive. The receptive sites for AII were the subfornical organ (SFO) and the preoptic area (POA) in the Japanese quail. Catecholaminergic fibers proceed from the POA to the SFO. Dipsogenic information generated by AII at the POA is transferred to the SFO through the Catecholaminergic nerve fibres. Plasma AII increased following dehydration and haemorrhage and returned to a normal level immediately after rehydration. Following dehydration, arginine vasotocin, aldosterone and corticosterone increased in plasma as well as AII. A single intraperitoneal injection of AII induced increases of arginine vasotocin, aldosterone and corticosterone in plasma. It seems that AII functions as a trigger for release of these other hormones during dehydration.

The catecholaminergic nerve supply to small intracerebral vessels following a cold injury to the mouse cortex.

A cold lesion was produced in the mouse parietal cortex. The damaged area was examined for alterations in the catecholamine fibres either by fluorescence microscopy or by electron microscopy. Within 24 h of injury many damaged catecholaminergic nerves were observed in close association with small intracerebral blood vessels. This relationship between nerves and blood vessels was not apparent in the control cortex. In the electron microscope, swollen non-myelinated axons containing an accumulation of dense-cored vesicles were observed close to the vessel wall but separated from it by astrocytic process. Six days after injury regenerating catecholaminergic nerve fibres were found close to immature capillaries. Axonal-like profiles containing dense-cored vesicles were observed adjacent to the endothelial call basement membrane. The number of regenerating nerves declined with time and the only fluorescent catecholaminergic nerves that remained 12 weeks after injury were in an area known to be rich in capillaries.

Effects of intracerebroventricular injection of d-amphetamine on metabolic, respiratory, and vasomotor activities and body temperatures in the rat.

Systemic and central administration of d-amphetamine both produced dose-dependent hypothermia in the rat at ambient temperature (Ta) 8 degrees C. The hypothermia was brought about solely by a decrease in metabolic heat production. However, at both Ta 22 and 30 degrees C, d-amphetamine produced hyperthermia accompanied by behavioral excitation. The hyperthermia was due to cutaneous vasoconstriction and increased metabolic heat production (due to behavioral excitation) at Ta 22 degrees C, whereas at Ta 30 degrees C the hyperthermia was due to cutaneous vasoconstriction, decreased respiratory evaporative heat loss, and increased metabolism (due to behavioral excitation). Furthermore, both the thermal and the behavioral responses induced by d-amphetamine were antagonized by pretreatment with intracerebroventricular administration of 6-hydroxydopamine (a depletor of central catecholaminergic nerve fibers). The data indicate that, by eliminating the interference of behavioral responses induced, d-amphetamine leads to an alteration in body temperature of rats by decreasing both metabolic heat production and sensible heat loss, probably via the activation of central catecholaminergic receptors.

The catecholamine precursor L-3,4-dihydroxyphenylalanine inhibits both heat production and heat loss mechanisms in the rabbit.

The effects of catecholamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) on the thermoregulatory responses of conscious rabbits to different ambient temperatures (Ta) (2, 22, and 30 degrees C) were assessed. Intravenous administration of L-DOPA alone, intravenous administration of L-DOPA plus R04-4602 (a peripheral decarboxylase inhibitor), and intraventricular administration of L-DOPA or norepinephrine all produced a hypothermia at Ta 2 degrees C. The hypothermia was due to a decrease in metabolic heat production (M). On the other hand, L-DOPA or norepinephrine produced both behavioral excitation and hyperthermia at both Ta 22 and 32 degrees C. At Ta 22 degrees C, the hyperthermia was due to decreased ear skin blood flow (EBF) and slightly increased M (due to behavioral excitation) whereas at Ta 32 degrees C the hyperthermia was due to EBF, decreased respiratory evaporative heat loss, and slightly increased M (due to behavioral excitation). Further, the temperature effects induced by L-DOPA were antagonized by pretreatment with 6-hydroxydopamine (a relative depletor of catecholaminergic nerve fibers) but not with haloperidol (a relative blocker of dopaminergic receptors). The data indicate that activation of central adrenergic receptors via the endogeneous release of norepinephrine with L-DOPA inhibits both heat production and heat loss mechanisms in the rabbit.

The pineal complex of the three-spined stickleback, Gasterosteus aculeatus L.

The pineal complex of the three-spined stickleback (Gasterosteus aculeatus L.) was investigated by light and electron microscopy, as well as fluorescence histochemistry for demonstration of catecholamines and indolamines. The pineal complex of the stickleback consists of a pineal organ and a small parapineal organ situated on the left side of the pineal stalk. The pineal organ, including the entire stalk, is comprised mainly of ependymal-type interstitial cells and photoreceptor cells with well-developed outer segments. Both unmyelinated and myelinated nerve fibres are present in the pineal organ. Nerve tracts from the stalk enter the habenular and posterior commissures. A small bundle of nerve fibres connects the parapineal organ and the left habenular body. The presence of indolamines (5-HTP, 5-HT) was demonstrated in cell bodies of both the pineal body and the pineal stalk, and catecholaminergic nerve fibres surround the pineal complex.

The role of the cholinergic system in the central control of thermoregulation in rats.

Systemic and central administration of methacholine (a synthetic choline derivative) both produced dose-dependent decreases in rectal temperature in rats at all the ambient temperatures studied. Both at room temperature (22 degrees C) and in the cold (8 degrees C), the hypothermia in response to methacholine application was brought about by both a decrease in metabolic heat production and an increase in cutaneous circulation. In the heat (29 degrees C), the hypothermia was due solely to an increase in respiratory evaporative heat loss. Furthermore, the methacholine-induced hypothermia was antagonized by central pretreatment of atropine (a selective blocker of cholinergic receptors), but not by the central administration of either 6-hydroxydopamine (a relative depletor of catecholaminergic nerve fibers) or 5,6-dihydroxytryptamine (predominately a serotonin depletor). The data indicate that activation of the cholinergic receptors within brain with methacholine decreases heat production and (or) increases heat loss which leads to hypothermia in rats.