Peptide YY-like immunoreactivity in the central nervous system of the rat

The concentration of peptide YY (PYY)-like immunoreactivity in rat brain and spinal cord was determined by radioimmunoassay. The highest concentrations were found in the cervical spinal cord (18.1 +/- 1.3 ng/g, mean +/- S.E.M.) and in the medulla oblongata (16.3 +/- 1.5 ng/g). Lower amounts were found in the pons and in the hypothalamus. Chromatographic analysis of the PYY-like immunoreactivity from various regions of the brain revealed 95% of the immunoreactive material to be indistinguishable from synthetic porcine PYY. PYY-immunoreactive nerve cell bodies could be demonstrated by immunocytochemistry in the medulla oblongata of colchicine-treated rats, the largest group of cells being found in the midline area between and partly in the raphe pontis and obscurus nuclei. Another large group of immunoreactive cells was detected more laterally in the medial parts of the gigantocellular reticular nucleus. A few cells, finally, were seen in the dorsal parts of the medulla, including the nucleus of the solitary tract. Varicose nerve fibers displaying PYY immunoreactivity were observed in many parts of the hypothalamus, pons, medulla and spinal cord.     

Distribution of choline acetyltransferase and acetylcholinesterase in the nervous system of the dog

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity were determined in 23 selected parts of the dog CNS and 4 parts of the peripheral nervous system. Maximum ChAT activity was found in the caudate nucleus and the ventral roots of the spinal cord. High activity was also present in the thalamus, the pons, the cerebral cortex, the medulla oblongata, the ventral spinal horns and the sciatic nerve. The lowest activity was measured in the cerebellum, the dorsal cord roots and the spinal ganglia. Maximum AChE activity was found in the caudate nucleus and the cerebellum. Relatively high activity was also present in the thalamus, the pons, the medulla oblongata, the grey matter of the spinal cord and the spinal ganglia. The lowest AChE activity was measured in the ventral and dorsal spinal roots.     

Vasoactive intestinal polypeptide immunoreactivity in the spinal cord of the guinea pig

Summary The distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the lower medulla oblongata and the spinal cord has been analyzed in guinea pigs. This study includes results obtained by colchicine treatment and transection experiments. In the spinal cord, numerous VIP-IR varicosities were observed in the substantia gelatinosa of the columna dorsalis; some were also found in the substantia intermedia and the columna anterior. The spinal VIP-IR nerve fibers were mainly of intraspinal origin and oriented segmentally. VIP-IR nuclei in the spinal cord extended dorsally into corresponding regions of the caudal medulla oblongata, namely from the substantia intermedia medialis and lateralis into the vagus-solitarius complex and from the nucleus spinalis lateralis into the area of the nucleus reticularis lateralis. Additional VIP-IR perikarya were observed in the pars caudalis of the nucleus spinalis nervi trigemini. The VIP-IR nuclei within the caudal medulla oblongata probably form a continuous system with those localized within the spinal cord. They may be involved functionally in the modulation of cardiovascular and respiratory regulation in the guinea pig.Supported by the DFG, Carvas SFB 90     

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata

The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus. The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.     

PKCγ免疫反应定位小鼠皮质脊髓束的实验研究

目的探讨显示皮质脊髓束在成年小鼠脑和脊髓中定位分布的简便有效方法。方法运用蛋白激酶Cγ（PKCγ）免疫组织化学染色法,观察成年ICR小鼠脑和脊髓中皮质脊髓束的定位和分布情况。结果PKCγ免疫阳性产物分布于大脑运动皮层第V层锥体细胞胞体和轴突中,锥体细胞的阳性纤维经内囊、中脑大脑脚底、脑桥基底部、下行至延髓锥体中。在延髓下段,PKCγ阳性纤维经锥体交叉后进入对侧脊髓灰质后联合背侧,形成背侧皮质脊髓束,在脊髓白质的后索腹侧深层下行,至骶髓3-4节段以下逐渐消失。在整个脊髓前索和外侧索中未见有PKCγ阳性纤维。结论PKCγ特异地表达于脊髓后索皮质脊髓束中,提示PKCγ免疫组织化学法是一种显示和观察皮质脊髓束精确定位的有效方法。     

Immunohistochemical studies on the serotonergic innervation of the pia mater

Summary The direct innervation of the pial blood vessels by serotonin neurons has been demonstrated with a modified peroxidase-antiperoxidase technique in the mammalian central nervous system. The pia mater covering the ventrolateral surface of the medulla oblongata is innervated by numerous varicose serotonin fibers originating from the serotonin neurons of the lower brainstem. Scattered serotonin fibers were observed in the pia mater in every part of the brain and spinal cord.     

Distribution of gastrin and CCK-like peptides in rat brain

Summary The distribution of gastrin and CCK-like peptides in the rat brain was studied by immunocytochemistry using an antiserum reacting equally well with both groups of peptides. Immunoreactive nerve cell bodies were detected in all cortical areas, in the hippocampus where they were particularly numerous, in the mesencephalic central gray and in the medulla oblongata. After colchicine treatment immunoreactive material appeared also in cell bodies of the magnocellular hypothalamic system. Immunoreactive nerve fibers were widely distributed in the brain. Particularly dense accumulations were seen in the hippocampus near the ventral surface of the brain, in the caudate nucleus, in the interpeduncular nucleus, the parabrachial nucleus, the dorsal part of the medulla oblongata and in the dorsal horn of the spinal cord. In the hypothalamus immunoreactive nerve fibers were observed in all nuclei, being most frequent in the ventromedial, dorsal and lateral hypothalamic nuclei. A rich supply of nerve fibers was seen in the outer zone of the median eminence and in the neurohypophysis. From previous immunochemical analysis it appears that the peptide demonstrated in most parts of the brain is identical with CCK-8. In the neurosecretory cell bodies of the hypothalamus, the median eminence and the neurohypophysis, however, the immunoreactive material is probably identical with gastrin.     

Histoenzmological mapping of ATPase and 5-nucleotidase in the spinal cord and medulla oblongata of hedgehog (Paraechinus micropus)

The contribution presented deals with the distribution of adenosine triphosphatase (ATP-A) and 5-nucleotidase (AMP-A) in the spinal cord and medulla oblongata of hedgehog. The highlights of this study are: (1) AMP-A activity is stronger in neuropil than in neurons, in all the areas of spinal cord and medulla oblongata. In the nerve cells the enzyme is localized at the peripheries of the neurons, whereas the cytoplasm and nuclei are completely free from enzymatic activity. Reaction in blood vessels is quite high both in gray and white matter. (2) ATP-A activity is seen mainly at the peripheries of the neurons. The neuropil activity varies from mild to intense. Reaction in blood vessels is quite strong in all the areas. (3) Fibrous bundles and tracts are negative for both the enzymes. (4) In general, the activity of ATP-A and AMP-A is strongest in cranial nerve nuclei, irrespective of their sensory or motor nature. The distribution of these enzymes has been correlated with the functions of various nuclei of spinal cord and medulla oblongata in hedgehog, and compared with other mammals.     

Pathogenesis of mouse hepatitis virus infection. The role of nasal epithelial cells as a primary target of low-virulence virus, MHV-S.

The pathogenesis of mouse hepatitis virus (MHV-S) infection in suckling and weanling mice was comparatively studied after intranasal inoculation. In sucklings, infectious virus as well as specific antigen was first detected in the nasal mucosa at 12 hr, then in the nerve cells of the olfactory bulbs. At this stage viral particles were demonstrated both in the supporting cells and olfactory cells of the nasal mucosa. In the posterior part of the brain and spinal cord, virus was detected on days 3 to 4 postinoculation when viral growth was clearly demonstrable in the liver, spleen and intestines. In weanlings too, infection was first established in the nasal mucosa, shedding infectious virus in the nasal washing until day 6 postinoculation, and later infection spread to the brain and spinal cord. In weanling mice, however, neither infectious virus nor viral antigen was detected in the liver or other visceral organs, while serum neutralizing antibody became detectable on day 5 postinoculation, increasing in titer thereafter. Histopathologically degenerative and necrotic changes were observed in the nasal mucosa and central nervous system of both age groups of animals coincidentally with the presence of viral specific antigen, while inflammatory response was much less prominent in sucklings. In the liver, spleen and intestines, however, some lesions were observed only in sucklings.     

Immunoglobulins and complement in demyelination induced in mice by Theiler's virus

Intracerebral inoculation of Theiler's murine encephalomyelitis virus (TMEV) produces chronic demyelination and persistent infection in the central nervous system (CNS) of susceptible SJL mice. This series of experiments examined the contribution of humoral immunity and C to myelin destruction. As in multiple sclerosis, mice persistently infected with TMEV had elevated levels of IgG and oligoclonal bands in the cerebrospinal fluid (CSF). Immunoblot studies revealed that even in animals exhibiting profound demyelination, IgG in the serum and CSF was directed primarily at virus antigen rather than at normal myelin components. Inflammatory cells positive for Ig were distributed mainly around blood vessels, but occasionally they infiltrated the spinal cord parenchyma. Rare examples of myelin sheaths positive for IgG were found by immunoelectron microscopy in spinal cord sections from infected mice; the third component of complement (C3) was commonly found in the walls of CNS blood vessels but not on myelin. Neither serum nor CSF IgG from infected mice bound to myelin sheaths or other CNS components in sections of normal syngeneic spinal cord. There were significantly more demyelinating lesions in infected mice depleted of C components with cobra venom factor. These data do not support a humoral autoimmune basis for the CNS demyelination that occurs in association with persistent TMEV infection. However, the humoral immune response directed at TMEV antigens may either limit virus spread or promote virus persistence.     

The alpha7 nicotinic receptors in human fetal brain and spinal cord

The alpha7 nicotinic acetylcholine receptor subtype is believed to be involved in the regulation of neuronal growth, differentiation and synapse formation during the development of the human brain. In this study the expression of the alpha7 nicotinic acetylcholine receptor was investigated in human fetal brain and spinal cord of 5-11 weeks gestational age. Both the specific binding of [125I]alpha-bungarotoxin to prenatal brain membranes and the expression of alpha7 mRNA were significantly higher in the pons, medulla oblongata, mesencephalon and spinal cord of 9-11 weeks gestational age compared with cerebellum, cortex and subcortical forebrain. A significant positive correlation between gestational age and the expression of alpha7 mRNA was observed in all brain regions except cortex. A positive correlation was also observed between the gestational age and the [125I]alpha-bungarotoxin binding in the pons, medulla oblongata, mesencephalon, and cerebellum. Consequently, a significant relationship between the alpha7 mRNA levels and the binding sites for [125I]alpha-bungarotoxin was found in the fetal brain. The increasing levels of the alpha7 nicotinic acetylcholine receptor during the first trimester support the important role of nAChRs for the development of the central nervous system.     

ts1, a Paralytogenic mutant of Moloney murine leukemia virus TB, has an enhanced ability to replicate in the central nervous system and primary nerve cell culture.

A temperature-sensitive mutant of Moloney murine leukemia virus TB (MoMuLV-TB), ts1, which is defective in intracellular processing of envelope precursor protein (Pr80env), also possesses the ability to induce hind-limb paralysis in infected mice. To investigate whether ts1 has acquired neurotropism and to determine to what extent it can replicate in the central nervous system, we compared viral titers in the spleen, plasma, spinal cord, and brain throughout the course of infection of mice infected with ts1 and parental wild-type (wt) MoMuLV-TB. In both the ts1- and wt-inoculated mice, the concentrations of infectious virus recovered from the plasma and spleen increased rapidly and reached a plateau by 10 days postinfection (p.i.). In contrast, virus concentrations in the spinal cord and brain of ts1-inoculated mice increased gradually and reached a titer comparable to that in the spleen and exceeding that in the plasma only at 25 to 30 days p.i. At this time, the virus titer was approximately 200X greater in ts1-infected spinal cord tissue and approximately 20X greater in ts1-infected brain tissue than in the same wt-infected tissues. Paralysis became evident at 25 to 30 days p.i. in ts1-inoculated mice, whereas the wt-inoculated mice were normal. In addition, a substantial amount of Pr80env was detected in the spinal cords of ts1-inoculated mice compared with that found in the spinal cords of wt-inoculated mice. The infectious virus isolated from ts1-infected nerve tissue was found to possess the characteristic phenotype of the ts1 virus. Microscopic lesions of ts1-inoculated mice at 30 days p.i. consisted of vacuolar degeneration of motor neurons and spongy change of white matter in the brain stem and spinal cord. Similar but less severe lesions were observed in wt-inoculated mice. With primary cultures of central nervous system tissue we showed that ts1 can infect and replicate in both neuron and glial cells. In contrast, although wt MoMuLV-TB replicated in glial cell-rich culture, viral replication was barely detectable in neuron-rich culture.     

Myelosuppressive Conditioning Using Busulfan Enables Bone Marrow Cell Accumulation in the Spinal Cord of a Mouse Model of Amyotrophic Lateral Sclerosis

Myeloablative preconditioning using irradiation is the most commonly used technique to generate rodents having chimeric bone marrow, employed for the study of bone marrow-derived cell accumulation in the healthy and diseased central nervous system. However, irradiation has been shown to alter the blood-brain barrier, potentially creating confounding artefacts. To better study the potential of bone marrow-derived cells to function as treatment vehicles for neurodegenerative diseases alternative preconditioning regimens must be developed. We treated transgenic mice that over-express human mutant superoxide dismutase 1, a model of amyotrophic lateral sclerosis, with busulfan to determine whether this commonly used chemotherapeutic leads to stable chimerism and promotes the entry of bone marrow-derived cells into spinal cord. Intraperitoneal treatment with busulfan at 60 mg/kg or 80 mg/kg followed by intravenous injection of green fluorescent protein-expressing bone marrow resulted in sustained levels of chimerism (∼80%). Bone marrow-derived cells accumulated in the lumbar spinal cord of diseased mice at advanced stages of pathology at both doses, with limited numbers of bone marrow derived cells observed in the spinal cords of similarly treated, age-matched controls; the majority of bone marrow-derived cells in spinal cord immunolabelled for macrophage antigens. Comparatively, significantly greater numbers of bone marrow-derived cells were observed in lumbar spinal cord following irradiative myeloablation. These results demonstrate bone marrow-derived cell accumulation in diseased spinal cord is possible without irradiative preconditioning.     

Localization of nerve growth factor-like immunoreactivity in rat nervous tissue

The use of immunofluorescence with affinity-purified antibodies enabled cytological localization of nerve growth factor-like material in the rat. Immunoreactivity was observed along various nerve tracts of the foetal rat brain and spinal cord at day 15 of gestation. Longitudinal pathways in ventral and dorsal spinal cord, ventral lower brain stem, posterior commissure, retroflex fascicle and in the olfactory bulb were all positive. A weaker and more widely spread immunostaining was visible in many areas in the central nervous system. Cranial nerves were strongly immunoreactive. Neuronal perikarya in the retina and the olfactory mucosa as well as filae olfactoriae and the olfactory nerve all the way to the olfactory bulb were also positive. In sensory ganglia and peripheral nerves most immunoreactivity was confined to supporting tissues, probably including Schwann cells. In irides, the pattern of immunoreactivity was similar to that of the sensory and autonomic innervation. More intensively fluorescent material was found in regrowing nerve fibres in iris transplants. Our histochemical results suggest that nerve growth factor and/or a related protein is present in large amounts along nerve pathways in supportive tissues of the peripheral nervous system as well as in the central nervous system during early development.     

Characterization of Canine Distemper Viruses Adapted to Neural Cells and Their Neurovirulence in Mice

Interaction of the Onderstepoort strain of canine distemper virus (CDV) with three established human neural cells, i.e. IMR-32 neuroblastoma, 118-MGC glioma and KG-1 oligodendroglioma, was examined, and adaptation of CDV to these cells was also attempted. The unadapted virus was found to grow at relatively low titers in the three neural cells inducing moderate to minimal cytopathic effects (CPE). The virus was successfully grown at high titers in these cells after 8 to 10 passages. Biological characteristics such as growth rate, morphology of CPE and plaque size changed after adaptation. Analysis by SDS-polyacrylamide gel electrophoresis, however, failed to show any difference in the molecular weight of component proteins among the unadapted and three adapted viruses. Inbred DDD strain of mice developed clinical signs after intracerebral inoculation with the unadapted virus but most of them survived with histological lesions of encephalitis. Neuroblastoma-adapted virus induced only transient clinical signs in some animals with mild encephalitic lesions in the gray matter. Increases in neurovirulence were found for viruses adapted to glioma and oligodendroglioma cells. Almost all mice inoculated with these two viruses at 3 weeks of age died within 8 days with histological lesions consisting of hyperemia, edema, severe degeneration of nerve cells and a few giant cells. Demyelinating lesions in the absence of inflammatory changes were observed in the cerebellum, pons and medulla oblongata of animals inoculated with oligodendroglioma-adapted virus.     

A neutralization-resistant Theiler's virus variant produces an altered disease pattern in the mouse central nervous system.

Theiler's murine encephalomyelitis virus infection of mice is an animal model for human demyelinating diseases. To further define the role of this virus in the disease process, we selected a virus variant resistant to neutralization by a monoclonal antibody to VP-1. This virus variant was then injected into SJL/J mice. Central nervous system tissue was compared between variant virus- and wild-type virus-infected mice. Within the brain, no large differences were observed between the two groups as to the distribution of inflammatory infiltrates around the injection site and the number of viral antigen-positive cells during the first weeks of the observation period. In contrast, in the spinal cord major differences were found between variant virus- and wild-type virus-infected mice regarding the number of inflammatory lesions, infected cells, and the size of the areas involved with time. By immunohistochemistry, equivalent numbers of infected cells could be found in the spinal cord 1 week postinfection (p.i.): however, after that time, the number of infected cells in the wild-type virus-infected mice continued to increase, whereas the virus-positive cells from the variant virus-infected mice gradually decreased. Thus, the number of viral antigen-containing cells peaked by 1 week p.i. in the variant virus-infected animals. Conversely, the number of infected cells in the spinal cords from mice inoculated with wild-type virus steadily increased until 8 weeks p.i. At this time (8 weeks p.i.), no more variant virus antigen-positive cells could be observed within the spinal cord. Plaque assay of central nervous system tissue confirmed these differences between the two groups observed by immunohistochemistry. No infectious variant virus could be isolated after 2 weeks p.i. from the brain and 4 weeks p.i. from the spinal cord, whereas infectious wild-type virus could be detected up to the end of the observation period (12 weeks p.i.). Virus which was isolated from variant virus-infected mice still retained the neutralization-resistant phenotype. These studies emphasize the important biological in vivo activity of Theiler's virus VP-1 in determining neurovirulence.     

GnRH在性成熟高白鲑神经系统及性腺中的分布定位

摘要：应用免疫组织化学方法,系统观察性成熟期高白鲑(Coregonus peled)神经系统及性腺中的促性腺激素释放激素( GnRH)的分布情况。结果表明,GnRH在大脑、小脑、中脑、脊髓、延髓中免疫阳性反应明显,且主要分布在神经元内。GnRH免疫阳性细胞在卵巢和精巢中均有分布,而且其阳性部位在卵巢主要分布于小生长期卵...     

Effect of ischaemia on protein synthesis in vitro

Changes in the incorporation of 14C-amino acids into proteins in vitro were followed under conditions of ischemia induced by abdominal aorta ligature and subsequent recirculation in dogs. Cell saps isolated from L-S spinal cord, spinal ganglia, the sciatic nerve and medulla oblongata were added to the incorporation mixture composed of ribosomes and an enzymatic system from intact brains. Cytosols isolated from ischemic animals affected the rate of in vitro protein synthesis moderately, while repeated ischemia caused a profound decrease in the incorporation of amino acids into proteins. Cytosols from L-S spinal cord and especially from spinal ganglia after three days of recirculation substantially enhanced incorporation thus indicating a massive response of these tissues to ischemic injury. Cell saps from the medulla oblongata increased amino acid incorporation into proteins in vitro in all experimental groups.     

Selective activation of microglia in spinal cord but not higher cortical regions following nerve injury in adult mouse

Neuronal plasticity along the pathway for sensory transmission including the spinal cord and cortex plays an important role in chronic pain, including inflammatory and neuropathic pain. While recent studies indicate that microglia in the spinal cord are involved in neuropathic pain, a systematic study has not been performed in other regions of the central nervous system (CNS). In the present study, we used heterozygous Cx3cr1 ^GFP/+mice to characterize the morphological phenotypes of microglia following common peroneal nerve (CPN) ligation. We found that microglia showed a uniform distribution throughout the CNS, and peripheral nerve injury selectively activated microglia in the spinal cord dorsal horn and related ventral horn. In contrast, microglia was not activated in supraspinal regions of the CNS, including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), primary and secondary somatosensory cortex (S1 and S2), insular cortex (IC), amygdala, hippocampus, periaqueductal gray (PAG) and rostral ventromedial medulla (RVM). Our results provide strong evidence that nerve injury primarily activates microglia in the spinal cord of adult mice, and pain-related cortical plasticity is likely mediated by neurons.