Distribution of dopamine-immunoreactive neuronal perikarya and fibres in the brain of a teleost, Gasterosteus aculeatus L. comparison with tyrosine hydroxylase- and dopamine-beta-hydroxylase-immunoreactive neurons.

The distribution of dopamine in the brain of the teleost Gasterosteus aculeatus L. was demonstrated with the indirect peroxidase-antiperoxidase immunohistochemical method using highly specific antibodies against a dopamine-glutaraldehyde-thyroglobulin conjugate. Dopamine-immunoreactive (DAir) neuronal somata were observed in all main brain regions. In the forebrain, DAir neurons were located in a continuous cell column extending from the caudal part of the olfactory bulbs to the preoptic area. The neurons lie lateral to the dorsal (and caudally to the subcommissural) portion of the ventral telencephalic area, and ventromedial to the central nuclei of the dorsal area. In the diencephalon, cerebrospinal fluid-contacting neurons were located in the paraventricular organ and in the subependymal layers of the dorsal and caudal zones of the periventricular hypothalamus. Small DAir neurons were observed in the suprachiasmatic nucleus, in the parvocellular preoptic nucleus and in the ventromedial thalamic nucleus, while large perikarya were observed dorsolateral to the dorsal zone of the periventricular hypothalamus ('PVO-accompanying cells'), in the posterior tuberal nucleus and in the most rostral portion of the mammillary bodies. Numerous small DAir neurons were located in the periventricular pretectal nucleus. In the brainstem, DAir neurons were observed in the isthmus region, in the dorsal raphe nucleus and in the lateral parts of the nucleus of the solitary tract. DAir perikarya were also observed in the area postrema. Direct comparison with the distribution of tyrosine hydroxylase- and dopamine-beta-hydroxylase-immunoreactivity (THir and DBHir) gave the following results: THir neurons were found in all areas where DAir neurons were located, except for the paraventricular organ and the dorsal and caudal zones of the periventricular hypothalamus, which were devoid of THir. DBHir (putatively noradrenergic or adrenergic) neurons were observed in the lateral parts of the nucleus of the solitary tract, and in the isthmus region. The DBHir neurons in the isthmus region, which have previously been shown to be noradrenergic, appeared to be identical with the THir and DAir neurons of the same area. DAir axons were found in high numbers in most parts of the brain. Especially dense innervation was found in the ventrolateral and posterior parts of the dorsal telencephalic area, the region surrounding the lateral recesses of the third ventricle, the interpeduncular nucleus, the dorsal and median raphe nuclei (the rostral raphe nuclei), and in the nucleus of the solitary tract.(ABSTRACT TRUNCATED AT 400 WORDS)

Distribution of N-acetylaspartate, N-acetylaspartylglutamate, free glutamate and aspartate following complete mesencephalic transection in rat neuraxis.

The distribution of N-acetylaspartate (NAA), N-acetylaspartylglutamate (NAAG), free glutamate (Glu) and aspartate (Asp) was studied in the neuraxis of rats 48 h after complete transection of brain stem at the intercollicular level. NAA remained unchanged above the transection level but decreased in the neur-axis segments caudal to the lesion. Glu was strongly depressed both in the segments rostral to the transection and in the ones caudal to it. No significant change was found for NAAG and Asp. These findings are consistent with the hypothesis that NAA may be involved in neurotransmission processes and provide further evidence for Glu as transmitter of descending and ascending pathways. In addition, the data obtained do not suggest a direct metabolic or functional relationship between NAA and NAAG nor between these N-acetylderivatives and free Glu and Asp.

Immunohistochemical evidence for GABAergic cell bodies in the medial nucleus of the trapezoid body and in the lateral vestibular nucleus in the guinea pig brainstem.

The presence of gamma-aminobutyric acid (GABA) in two brainstem nuclei is demonstrated by using a pre-embedding immunohistochemical procedure followed by staining intensification. Firstly, immunoreactivity was found in numerous cell bodies and profiles of the medial nucleus of the trapezoid body (MNTB). Secondly, numerous neurons including giant Deiters' cells, terminals and fibers were strongly labelled within the lateral vestibular nucleus (LVN). These observations suggest that the inhibitory part of the efferent innervation of outer hair cells in the cochlea can originate from the MNTB, and that GABAergic neurons in the LVN may contribute to information processing within this nucleus.

Presence of dopamine-immunoreactive cell bodies in the catecholaminergic group A15 of the sheep brain.

Antisera were raised in rabbits against dopamine or noradrenaline conjugated to thyroglobulin with glutaraldehyde. These antisera, tested in enzyme linked immunosorbent assay and immunohistochemistry specifically recognized their homologous antigens. With the aid of anti-tyrosine hydroxylase, anti-aromatic aminoacid decarboxylase, anti-dopamine-beta-hydroxylase, anti-dopamine, and anti-noradrenaline antisera, immunohistochemical reactions were performed on glutaraldehyde fixed sections of sheep diencephalon in order to determine the presence of dopamine in the catecholaminergic group A15. Perikarya of this nucleus were stained with anti-tyrosine hydroxylase, anti-aromatic aminoacid decarboxylase and anti-dopamine, but not with anti-dopamine-beta-hydroxylase or anti-noradrenaline. Both of these latter antisera stained fibers within this area. So as recently found in the rat, we could conclude that dopamine is present in group A15 of the sheep.

Contribution of brainstem edema to neurophysiologic deterioration in the cat infusion edema model.

These results show that infusion edema produces a significant increase in brainstem tissue water similar to the distribution seen after traumatic injury. The increased brainstem water of 0.24 cc is equivalent to a brainstem volume rise of 7.26% and was sufficient to cause a marked reduction in the PVI and sustained elevation of the ICP. Despite the ICP rise, somatosensory and brainstem potentials are only mildly affected and return to normal within 8 hr. The fact that severe fluid percussion injury results in obliteration of BAER immediately after impact would suggest that the neurologic deterioration seen in the fluid percussion model of injury is due to direct structural damage of the tissue, which was received at the moment of impact, and not to the compressive effect of the developing brainstem edema at levels achieved in these experiments (7.62% swelling). As in other mechanical models, edema results in secondary compression of the tissue and contributes to the general brain swelling, which if unabated could lead to tentorial herniation and death. In these infusion studies, we must conclude that in some cases, mild secondary compression was sufficient to affect other control centers and produce systemic failure at levels of edema that do not result in alteration of evoked potentials. This might explain the deaths of those animals that occurred during the infusion period in which brainstem potentials remained intact.

Regional distribution of metabotropic glutamate response in the rat brain using Xenopus oocytes.

The regional distribution of metabotropic L-glutamate responses was investigated in Xenopus oocytes injected with poly(A)+-RNA from a rat brain which was separated into 3 parts: cerebrum, cerebellum and brainstem. Under voltage-clamp, oscillatory current responses were induced more in cerebellum or brainstem poly (A)+-RNA-injected oocytes, and less in cerebrum poly(A)+-RNA-injected oocytes. These results suggest that the metabotropic glutamate receptor is distributed mostly in cerebellum and brainstem.

Ultrastructure of primary afferent fibres and terminals expressing alpha-galactose extended oligosaccharides in the spinal cord and brainstem of the rat.

The ultrastructural characteristics of primary afferent fibres, which express alpha-galactose extended oligosaccharides recognized by LD2 and LA4 monoclonal antibodies, and the subcellular localization of these oligosaccharides were studied. LD2 and LA4 antibodies both label intensely the plasma membrane of primary afferent fibres, and with LD2 antibody all immunoreactive profiles also possessed strong intracellular staining. In contrast, intracellular staining with LA4 antibody was observed in only a subpopulation of stained profiles. LD2-immunoreactive fibres were detected in trigeminal and Lissauer tracts and in lamina I (LI) and lamina II (LII), and appeared as a mixture of unmyelinated and myelinated fibres. The highest density of LD2-immunoreactive synaptic boutons was found in lamina II outer (LIIo). Many of the terminals were simple dome-shaped terminals, making single asymmetric synapses over small and medium-sized dendritic shafts and dendritic spines. All LA4-immunoreactive fibres were unmyelinated. In addition, some small scalloped central-glomerular terminals contacting two or three dendrites were found. LA4-immunoreactive fibres were found more frequently than terminals and appeared most heavily immunostained in trigeminal and Lissauer tracts. In the neuropil of LI and LII, LA4 profiles were generally very weakly immunostained, although a small sample of immunostained synaptic boutons was detected. All LA4-immunoreactive terminals were found in lamina II inner (LIIi) and made simple asymmetric axodendritic synapses. In addition to axons and terminals, some dendrites exhibited LD2 immunoreactivity and this was most intense in the region of synaptic vesicles. In addition to neurons, some endothelial cells were immunostained with LD2 antibody and astrocytes were immunostained with LA4 antibody.

Morphology and distribution of primary afferent fibres expressing alpha-galactose extended oligosaccharides in the spinal cord and brainstem of the rat. Light microscopy.

The light microscopic morphology and distribution of non-substance P-containing small primary afferent fibres were studied. These fibres were labelled using LD2 and LA4 monoclonal antibodies which recognize alpha-galactose extended oligosaccharides expressed by primary afferent neurons. The LD2 and LA4 antibodies immunostained small primary afferent fibres ending mainly in lamina II of the spinal cord dorsal horn and trigeminal subnucleus caudalis of the rat. The lamination pattern of both types of primary afferents was assessed using an image analysis system. The highest density of LD2-immunoreactive fibres was located in a patchy band located in lamina II outer, while LA4-immunoreactive fibres were distributed mainly through lamina II inner. In lateral regions of cervical and lumbar dorsal horn the LA4-immunoreactive band is broader and comprises almost all lamina II. In contrast to substance P-containing primary afferents, a low density of LD2- or LA4-immunoreactive fibres was found in lamina I, and no terminal fields were found in lamina V or lamina X of the spinal cord or in levels of the trigeminal system outside the subnucleus caudalis. Both antibodies also labelled the parent fibres in the white matter fasciles. LD2-immunoreactive fibres were located in the dorsal roots, medial regions of the Lissauer tract, dorsal columns of the spinal cord, outer regions of the spinal trigeminal tract and dorsal to the cuneatus and gracilis nuclei. In contrast, LA4-immunoreactive fibres were restricted to the dorsal roots, medial and lateral regions of the Lissauer tract and the outer regions of the trigeminal tract. Immunostained fibres in the rootlets of the X and IX nerves and immunoreactive terminal arborizations in various subnuclei of the nucleus tractus solitarius were seen using both antibodies. These results show that subpopulations of small primary afferents stained by LD2 and LA4 antibodies have distinct patterns of central distribution and are consistent with a subdivision of small primary afferents into peptide- and non-peptide-containing groups.

Distribution of phenylethanolamine N-methyltransferase cell bodies, axons, and terminals in monkey brainstem: an immunohistochemical mapping study.

Adrenaline (epinephrine) is an important candidate transmitter in descending spinal control systems. To date intrinsic spinal adrenergic neurons have not been reported; thus adrenergic input is presumably derived from brainstem sites. In this regard, the localization of adrenergic neurons in the brainstem is an important consideration. Maps of adrenergic cell bodies and to a lesser extent axons and terminal fields have been made in various species, but not in monkeys. Thus, the present study concerns the organization of adrenergic systems in the brainstem of a monkey (Macaca fascicularis) immunohistochemically mapped by means of an antibody to the enzyme phenylethanolamine N-methyltransferase (PNMT). PNMT-immunostained cell bodies are distributed throughout the medulla in two principal locations. One concentration of labeled cells is in the dorsomedial medulla and includes the nucleus of the solitary tract (NTS), the dorsal motor nucleus of the vagus (X), and an area ventral to X in a region of the reticular formation (RF) known as the central nucleus dorsalis (CnD) of the medulla. A few scattered cells are observed in the periventricular gray just ventral to the IVth ventricle and on midline in the raphe. The second major concentration of PNMT-immunostained cells is located in the ventrolateral RF, lateral and dorsolateral to the inferior olive (IO), including some cells in the rostral part of the lateral reticular nucleus (LRN). Terminal fields are located in the NTS, X, area postrema (AP), and the floor of the IVth ventricle in the medulla and pons. A light terminal field is also observed in the raphe, particularly raphe pallidus (RP). A heavy terminal field is present in locus coeruleus (LC). Fibers labeled for PNMT form two major fiber tracts. One is in the dorsomedial RF extending as a well-organized bundle through the medulla, pons, and midbrain. A second tract is located on the ventrolateral edge of the medulla and caudal pons. Fibers in this tract appear to descend to the spinal cord. A comparison with maps of other catecholamine neurons in primates is discussed, confirming that the distribution of the adrenergic system in monkeys is similar to that described in the human.

Distribution of serotonin immunoreactive neurons in the brainstem of the hamster, guinea pig, rabbit, and rat.

Immunohistochemical techniques were employed to study the distribution of serotonin (5-HT) immunoreactive neurons in the brainstem of the hamster, guinea pig, rabbit and rat. 5-HT neurons were principally found to be concentrated in the midline raphe nuclei, particularly, the raphe pallidus, raphe obscurus, raphe magnus, raphe median, raphe pontis and raphe dorsalis nuclei. Characteristically, these cell bodies are displayed in bands or wing-like patterns which extend laterally from the raphe into reticular formations. The formations often appear to blend with the catecholamine system. They are particularly evident in the brainstems of the rabbit and hamster which contain wider and more lateral extensions of the serotonergic (5-HT) neurons than those observed in the brainstems of the rat and guinea pig. The widespread distribution of 5-HT immunoreacted cell bodies in the brainstem shows that there are significant prospects of 5-HT in neuronal activities.

Distribution of serotonin-immunoreactive neurons in the brain of sockeye salmon fry.

The organization of the serotonergic cell groups in the brainstem of fishes and amphibians has received relatively little attention. It has been generally assumed that they are little differentiated and constitute a median cell column throughout the brainstem, and that laterally migrated serotonergic cell groups are largely lacking. In the present study we present evidence to the contrary. By the use of a sensitive immunocytochemical technique for the visualization of serotonin-immunoreactive (5HTir) neurons, we have been able to make a detailed delineation of the putatively serotonergic neuronal groups throughout the brain. In the epithalamus, 5HTir neurons were located in the left habenular nucleus in its dorsal subdivision. 5HTir neural elements, primarily photoreceptor cells, were present throughout the pineal organ and in some cases also in the parapineal organ. In the periventricular zones of the hypothalamus and posterior tuberculum, 5THir cerebrospinal fluid-contacting neurons were located in the paraventricular organ and in the dorsal, ventral and caudal zones of the periventricular hypothalamus. In the dorsal thalamus/synencephalon, 5THir neurons surround the tractus habenulo-interpeduncularis (fasciculus retroflexus). In the brainstem, several groups of 5HTir neurons could be discerned, that for reasons of topological similarity were named according to Lidov and Molliver a raphe pallidus/obscurus-complex (B1 and B2), raphe magnus (part of B3), median raphe (B8) possibly including raphe pontis (B5), raphe dorsalis (B4, B6 and B7), and B9. 5HTir neurons were observed in the central gray of the IVth ventricle, dorsal to the noradrenergic isthmal neurons and lateral to the brachium conjunctivum, in an area topologically equivalent with the dorsal subdivision of the locus coeruleus in mammals. In addition, small numbers of 5HTir neurons were located in the lobi faciales. Thus, the presence of well-differentiated groups of migrated serotonergic neurons is not an advanced trait of amniote brains, but may be a pattern common to all vertebrates.

The concentration of neuropeptide Y immunoreactivity falls with age selectively in microdissected regions of the ventrolateral medulla of spontaneously hypertensive and normotensive Wistar-Kyoto rats.

The concentrations of neuropeptide Y immunoreactivity were measured in microdissected regions enriched in noradrenergic (A1, A2, A6) and adrenergic (C1, C2, C3) nuclei of the brainstem, and in the nucleus of the spinal tract of the trigeminal nerve (Sp5C) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at 8, 18 and 31 weeks of age. The aim of this study was to compare the manner in which changes in neuropeptide Y immunoreactivity levels related to increases in blood pressure with ageing in each rat strain. The concentration of neuropeptide Y immunoreactivity in the A1 nucleus progressively fell with increasing age in both SHR and WKY. In contrast, the levels of neuropeptide Y immunoreactivity in the C1 region fell at 18 weeks of age but did not fall further by 31 weeks. No significant age-related changes occurred in the concentrations of neuropeptide Y immunoreactivity in the A2, C2, A6 and Sp5C nucleus. The levels of neuropeptide Y immunoreactivity in the C3 region were below assay sensitivity. The neurochemical changes that occur in the A1 nucleus are consistent with the increase in blood pressure observed with ageing in both rat strains. However, this observation alone does not account for the elevated blood pressure measured in the SHR strain.

[Indices of RNA metabolism in the brain stem of rats under superlethal exposure to ionizing radiation]. / Nekotorye pokazateli metabolizma RNK v stvole golovnogo mozga krys pri sverkhletal'nom vozdeistvii ioniziruiushchei radiatsii.

A study was made of the content of hnRNA, nuclear poly(A) RNA and biosynthesis of rlnRNA in truncus cerebri of rats divided into 3 groups by the forced swimming test 6-8 min and 60 min after a short-term exposure to sparsely ionizing radiation of 100 Gy. The observed changes in the nuclear RNA metabolism can subsequently lead to the impairment of the synthesis of proteins required for normal functioning of CNS, and to the development of CNS syndrome.

Effects of lipofuscin on in situ hybridization in human neuronal tissue.

In situ hybridization is a highly sensitive technique for detecting nucleic acid sequences within tissues, and is frequently employed in neurovirology. However, this technique requires many appropriate controls in order to recognize and avoid potential artifactual hybridization. We have encountered abundant reaction to lipofuscin in neurons in human peripheral and central nervous systems, using various DNA probes, which could be misinterpreted as positive signals. This pseudohybridization reaction was resistant to treatment with RNase or DNase and was also present in tissue sections treated with hybridization mixture or nuclear autoradiographic emulsion in the absence of any radioactive probes. Characteristics used to distinguish between authentic in situ hybridization and the reaction to neuronal lipofuscin include cellular localization, color, margins and granular appearance, sensitivity to treatment with nucleases and the effect of exposure time on signal intensity. These guidelines should be used to avoid potential misinterpretation of in situ hybridization results with human tissue.

Determination of sulfide in brain tissue by gas dialysis/ion chromatography: postmortem studies and two case reports.

An analytical method for the determination of sulfide in human and rat brain is described. It utilizes a continuous flow gas dialysis pretreatment and quantitation by ion chromatography with electrochemical detection. Rat brain sulfide levels were reliably measured after fatal intoxication by intraperitoneal injection of NaHS. By expeditious analysis of samples it was possible to demonstrate the presence of endogenous levels of sulfide in both rat and human brain as well as to measure elevated brain levels of sulfide after intoxication. In postmortem rat brain tissue, elevated sulfide levels could still be reliably demonstrated 96 h after death if the bodies had been refrigerated at 4 degrees C. Two case studies of human hydrogen sulfide inhalation fatalities are presented. The described method was able to measure significantly elevated sulfide levels in both cases.

[The DOPA and dopamine content in the hypothalamus and brain stem of rats with an experimental stomach ulcer against a background of a course of acupuncture]. / Soderzhanie DOFA i dofamina v gipotalamuse i stvole mozga krys pri éksperimental'noi iazve zheludka na fone kursa akupunktury.

In experiments on rats with experimental ulcer of the stomach (EUS) using spectrofluorometric method the increase of DOPA and dopamine (DA) in brain stem, has been revealed as well as DOPA in hypothalamus. Change of the level of DOPA takes place at an early stage of ulcer formation. Acupuncture (AP) inserts essential corrections into the distribution of catecholamines under study. So, the content of DOPA and DA in hypothalamus and particularly in the brain stem in rats with EUS against the background of AP sharply increases. It has been supposed that AP realizes its therapeutic influence during ulcer disease due to the alteration of catecholaminergic brain system.

Further evidence for excitatory amino acid transmission in lamprey reticulospinal neurons: selective retrograde labeling with (3H)D-aspartate.

The distribution of radiolabeled neurons in the brain stem of Lampetra fluviatilis was studied following unilateral injections of (3H)D-aspartate in the rostral spinal cord. After survival periods of 1-3 days, labeled perikarya were present within and nearby the posterior, middle, and anterior rhombencephalic reticular nuclei and in the mesencephalic reticular nucleus. The highest number of (3H)D-aspartate labeled cell bodies were present in the posterior rhombencephalic reticular nucleus. The labeled reticulospinal neurons were distributed mainly ipsilateral to the injection site and included the giant Müller cells as well as medium-sized and small neurons. Contralateral labeling occurred in cell bodies scattered along the lateral margin of the rhombencephalic reticular formation, the most rostral of these contralaterally projecting neurons being the Mauthner cell. The (3H)D-aspartate labeling correlates with previous electrophysiological studies showing that lamprey reticulospinal neurons utilize excitatory amino acid transmission.

Acute hydrogen sulfide poisoning. Demonstration of selective uptake of sulfide by the brainstem by measurement of brain sulfide levels.

The possibility of measuring sulfide levels in the central nervous system (CNS) opens up many avenues for exploration. In acute hydrogen sulfide (H2S) poisoning, death results from loss of central respiratory drive. To date, however, measurement of brain sulfide has not been possible. By employing gas dialysis and ion chromatography coupled to electrochemical detection, rat brain sulfide levels could be measured either following inhalation of H2S or after injection of sodium hydrosulfide (median lethal dose, [LD50] = 14.6 +/- 1.00 mg/kg). Accumulation of brain sulfide was linearly proportional to the dose over the range 0.50 LD50 to 3.33 LD50 units, and was strongly correlated with mortality data (R = 0.947). Furthermore, analysis of untreated (control) brain showed an endogenous sulfide level of 1.57 +/- 0.04 micrograms/g (mean +/- SE; N = 16). Studies on various rat brain regions (brainstem, cerebellum, hippocampus, striatum and cortex) showed that the endogenous sulfide level of brainstem, 1.23 +/- 0.06 micrograms/g, was significantly lower than that of the other brain regions. Net uptake of sulfide was greatest in the brainstem (3.02 micrograms/g) compared to the other regions as was the selective accumulation of sulfide as calculated from normalized blood flow rates. The results of subcellular fractionation demonstrated that sulfide was detectable in fractions enriched in myelin, synaptosomes and mitochondria. Approximately one-quarter of the endogenous sulfide content of whole rat brain was found in the mitochondrial fraction. The sulfide content of these fractions increased 2- to 3-fold after 50 mg/kg NaHS, the greatest increases occurring in myelin- and mitochondrial-enriched fractions.

[Effect of acupuncture on the catecholamine content in the hypothalamus and brain stem of rats with an experimental stomach ulcer]. / Vliianie akupunktury na soderzhanie katekholaminov v gipotalamuse i stvole mozga krys pri éksperimental'noi iazve zheludka.

Significant increase of dopamine (DA) in hypothalamus and epinephrine (E) in the brain stem were revealed in the experiment on rats with experimental gastric ulcer (EGU). An acupuncture (AP) session produces a prominent increase in DOPA and especially DA in hypothalamus of the rat with EGU. Under the same conditions A, DOPA and DA in the brain stem increased as compared to the control. It is assumed that acupuncture produces a correcting effect on the reconstructive processes of catecholaminergic systems of the brain occurring in visceral pathology.