Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

With the use of several region-specific antisera and the peroxidase-antiperoxidase (PAP) technique, several regulatory polypeptides were localized in nerves of the kidney. Neuropeptide Y (NPY)- immunoreactivity (IR), neurotensin (NT)-IR and vasoactive intestinal polypeptide (VIP)-IR occurred at high densities in all segments of the renal arterial system forming a perivascular plexus. Furthermore, NT-IR nerves were particularly frequent at the juxtaglomerular apparatus (JGA). Calcitonin gene-related peptide (CGRP)-IR was mainly concentrated in nerves supplying the hilus arteries and the JGA. Substance P (SP)-IR was predominantly found in large varicosities close to large renal arterial vessels and in the vicinity of the JGA. Somatostatin (SOM)-IR was only observed in single varicosities located at the media-adventitia border of large renal hilus arteries. The peptidergic nerves are correlated to their ultrastructural counterpart. In addition, the distribution patterns and the frequency of the different types of renal peptidergic nerve fibres are evaluated and compared. The functional role of these neuropeptides and their origin within the efferent branch of this part of the peripheral autonomic nervous system is discussed. Furthermore, the implication of some of the neuropeptides studied in afferent renal innervation is also substantiated.
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PMID:Neuropeptide (neuropeptide Y, neurotensin, vasoactive intestinal polypeptide, substance P, calcitonin gene-related peptide, somatostatin) immunohistochemistry and ultrastructure of renal nerves. 245 14

Intracellular electrodes filled with 4% horseradish peroxidase (HRP) were used to impale Purkinje cells in zone x of the cat's cerebellum. Subsequent to recording responses to bilateral stimulation of the ulnar, radial, and sciatic nerves, the cells were injected with HRP. Intracellularly labeled Purkinje cells were located and correlated with the physiological data. Purkinje cells in zone x respond primarily to stimulation of the ipsilateral forelimb. However, they have broad receptive fields in that most also receive inputs from stimulation of the contralateral forelimb or from more than one forelimb nerve; a few respond to activation of the hindlimb. The distribution of the recurrent collaterals of zone x Purkinje cells has several features that are similar to those from zones a,b, and c: 1) they have a similar number of varicosities within the plexus; 2) they distribute primarily in the sagittal as compared to the transverse plane; and 3) most varicosities in the plexus are located within the Purkinje cell layer. However, several characteristics distinguish the collaterals of zone x Purkinje cells. First, they have a greater transverse extent than those derived from Purkinje cells in zones a,b, and c. Second, they have a higher percentage of collaterals that extend to more superficial aspects of the molecular layer as well as to deep levels of the granule cell layer. The rostral extent of zone x has not been clearly defined in previous studies. On the basis of anatomical and physiological data derived from the present study it appears that Purkinje cells located in lobule Va have physiological and morphological properties similar to those observed for Purkinje cells in more caudal folia of lobule V. Thus, on the basis of the organization of local circuits, it appears that zone x extends at least to the most rostral folia of lobule V. In conclusion, these data suggest that Purkinje cells in zone x may not be involved in controlling the movements of specific muscles, as may be the case in other cortical zones. Rather, it could be hypothesized that Purkinje cells in zone x have a more generalized role in coordinating agonist and antagonist muscle groups in one limb or regulating patterns of movement between limbs.
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PMID:Quantitative analysis of the recurrent collaterals derived from Purkinje cells in zone x of the cat's vermis. 245 95

The afferent connections of the substantia innominata (SI) in the rat were determined employing the anterograde axonal transport of Phaseolus vulgaris leucoagglutinin (PHA-L) and the retrograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP), in combination with histochemical procedures to characterize the neuropil of the SI and identify cholinergic cells. Both neurochemical and connectional data establish that the SI is organized into a dorsal and a ventral division. Each of these divisions is strongly affiliated with a different region of the amygdala, and, together with its amygdalar affiliate, forms part of one of two largely distinct constellations of interconnected forebrain and brainstem cell groups. The dorsal SI receives selective innervation from the lateral part of the bed nucleus of the stria terminalis, the central and basolateral nuclei of the amygdala, the fundus of the striatum, distinctive perifornical and caudolateral zones of the lateral hypothalamus, and caudal brainstem structures including the dorsal raphe nucleus, parabrachial nucleus, and nucleus of the solitary tract. Projections preferentially directed to the ventral SI arise from the medial part of the bed nucleus of the stria terminalis, the rostral two-thirds of the medial nucleus of the amygdala, a large region of the rat amygdala that lies ventral to the central nucleus, the medial preoptic area, anterior hypothalamus, medialmost lateral hypothalamus, and the ventromedial hypothalamus. Both SI divisions appear to receive afferents from the dorsomedial and posterior hypothalamus, supramammillary region, ventral tegmental area, and the peripeduncular area of the midbrain. Projections to the SI whose selectivity was not determined originate from medial prefrontal, insular, perirhinal, and entorhinal cortex and from midline thalamic nuclei. Findings from both PHA-L and WGA-HRP experiments additionally indicate that cell groups preferentially innervating a single SI division maintain numerous projections to one another, thus forming a tightly linked assembly of structures. In the rat, cholinergic neurons that are scattered throughout the SI and in parts of the globus pallidus make up a cell population equivalent to the primate basal nucleus of Meynert (Mesulam et al.: Neuroscience 10:1185-1201, '83). PHA-L-filled axons, labelled from lectin deposits in the dorsal raphe nucleus, peripeduncular area, ventral tegmental area, or caudomedial hypothalamus were occasionally seen to approach individual cholinergic neurons int he SI, and to contact the surface of such cells with axonal varicosities (putative synaptic boutons.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neural associations of the substantia innominata in the rat: afferent connections. 246 72

Using two-color immunoperoxidase staining combined with the retrograde transport of horseradish peroxidase injected into the rostral thoracic spinal cord, substance P-immunoreactive (SPI) and serotonin-immunoreactive (5HTI) varicosities have been observed in contiguity with medullary bulbospinal phenylethanolamine N-methyl transferase-immunoreactive (PNMTI) neurons of the C1, C2, and C3 cell groups. Since PNMTI terminals in the spinal cord are concentrated among sympathetic preganglionic neurons (SPGN) in the intermediolateral cell column, the close anatomical associations shown in the present study indicate that substance P- and serotonin-containing pathways in the medulla likely affect activity of SPGN via adrenergic bulbospinal neurons.
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PMID:Immunocytochemical evidence for substance P and serotonin input to medullary bulbospinal adrenergic neurons. 246 93

Afferent terminal arbors in the hamster LGBd were labelled with horseradish peroxidase (HRP) implanted into the optic tract. Three morphologically distinct terminal types, each with a different regional distribution, were observed. Type R1 terminals are large, ovoid swellings and are predominantly distributed medially within the nucleus. Type R2 terminals are very small, clustered varicosities and are distributed laterally and ventrally. Type R3 terminals are medium in size and their distribution overlaps with that of Type R1 and R2 terminals.
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PMID:Distribution of morphologically different retinal axon terminals in the hamster dorsal lateral geniculate nucleus. 246 68

We have studied the serotonergic (5-HT) projection to the cat superior colliculus (SC) using serotonin antibody immunocytochemistry and retrograde transport of peroxidase-conjugated wheatgerm agglutinin (WGA-HRP). In 3 experiments, the two labels were combined in order to double label cells with both anti-5-HT and WGA-HRP. In the remaining experiments, the two labels were examined separately. Serotonin-like immunoreactive fibers were found throughout all layers of SC, but were most densely distributed within the zonal and upper superficial gray layers. Most 5-HT fibers were thin and had characteristic varicosities and terminal swellings. At the EM level, immunoreactive terminals and varicosities were found to contain small agranular vesicles and occasionally large granular vesicles (LGVs). Conventional synaptic densities were only rarely observed. Injections of WGA-HRP into SC resulted in labeling of neurons throughout the dorsal raphe nucleus and surrounding ventrolateral periaqueductal gray. Only a few cells were found in the raphe medianus and raphe pontis and none within the raphe magnus or other medullary raphe nuclei. Cells in the dorsal raphe giving rise to the SC projection varied in shape, size, and morphology and must represent more than one cell type. The morphology of these cells was indistinguishable from that of cells in the dorsal raphe which were double labeled by anti-5-HT and WGA-HRP. We conclude that the 5-HT innervation of the superior colliculus varies in density in different laminae, arises from several different cell types, and originates primarily from the dorsal raphe nucleus with minor projections from raphe medianus and raphe pontis.
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PMID:Origin, distribution, and morphology of serotonergic afferents to the cat superior colliculus: a light and electron microscope immunocytochemistry study. 246 16

The aim of this work was to study the ultrastructural distribution of substance P-like immunoreactivity in laminae I and II of rat spinal cord and trigeminal subnucleus caudalis in relation to synaptic glomeruli. A bispecific monoclonal antibody directed against substance P and horseradish peroxidase was used, combining sensitive immunocytochemistry with preservation of fine ultrastructural detail. Some of the quantitative observations were carried out with an automated image analysis system. The study revealed that in lamina I of the spinal cord, almost all immunoreactive profiles counted were nonglomerular, and a considerable number of them contacted medium-size or large dendrites or were in direct contact with other vesicle-containing profiles. In ventral lamina II, 9.4% of the labeled axonal varicosities were central boutons of type I glomeruli (CI). They could be identified by their scalloped contour, number and types of peripheral profiles, reduced density of mitochondria, and localization in the dorsal horn. However, these immunoreactive glomerular CI boutons (14.1% of the total number of CI) differed statistically from the prevailing population of nonimmunoreactive CI, by being surrounded by less peripheral neuronal profiles, which established fewer synapses. In addition, they contained more than three dense-core vesicles per central profile. In the trigeminal subnucleus caudalis laminae I and II, the substance P fibers and varicosities had a plexiform orientation at the light microscopic level, which contrasted with the mainly rostrocaudal orientation of the spinal cord's lamina II plexus. However, the main ultrastructural findings were similar. These results demonstrate that substance P-like immunoreactivity occurs in a large number of type I synaptic glomeruli with specific morphological features and reinforce the current concept that the substantia gelatinosa of the spinal cord and trigeminal subnucleus caudalis are homologous structures.
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PMID:Morphological characterization of substance P-like immunoreactive glomeruli in the superficial dorsal horn of the rat spinal cord and trigeminal subnucleus caudalis: a quantitative study. 246 97

With the peroxidase-antiperoxidase (PAP) preembedding immunocytochemical method the luteinizing hormone-releasing hormone (LHRH) containing fibres in the mesencephalic central grey substance (MCG) of male and female rats were studied light and electron microscopically. Thin unmyelinated LHRH immunoreactive fibres were found in the MCG up to the ponto-mesencephalic junction in a ventral sub- and intraependymal position. Especially in the middle part of the MCG, LHRH reactive fibres were found in two or three rostrocaudally orientated ventromedial thickenings of the ependymal lining. Ultrastructurally, LHRH varicosities contained immunopositive secretory granules with a diameter of approximately 110 nm. Because the LHRH varicosities were not observed to make any synaptic contact with dendrites of MCG cells, it seems very likely that LHRH influences MCG neurons in a nonsynaptic way. No apparent differences were found between male and female rats.
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PMID:Characterization of luteinizing hormone-releasing hormone fibres in the mesencephalic central grey substance of the rat. 247 15

The distribution and morphology of glutamatergic synapses on Drosophila bodywall muscle fibers were examined at the single-synapse level using immunocytochemistry and electrophysiology. We find that glutamate-immunoreactive motor endings innervate the entire larval bodywall musculature, with each muscle fiber receiving at least one glutamatergic ending. The innervation is initiated at stereotyped locations on each muscle fiber from where moderately branched varicose nerve processes project over the internally facing muscle surface. Individual muscle fibers have distinct stereotypic patterns of nerve endings that occupy characteristic regions on the cell surface. The muscle-specific branching pattern of motor endings is reiterated by segmentally homologous fibers. Two morphological types of innervating nerve processes can be distinguished by their bouton size distributions: (1) Type I processes, which have localized branching and a broad size distribution of relatively large varicosities ranging up to 8 microns (mean diameter, 3.1 +/- 1.6 microns; +/- SD, n = 521), and (2) thinner Type II processes, which have a narrower distribution of small varicosities with a mean diameter of only 1.4 +/- 0.6 microns (+/- SD, n = 214). Immunoelectron microscopy with peroxidase-labeled second antibody demonstrates that the varicosities are surrounded by a subsynaptic reticulum, that they contain immunoreactive vesicles of about 30-50 nm, and thus probably represent synaptic release sites. By iontophoretic application of glutamate we mapped the responsive sites on the muscle surface and found an excellent correspondence between transmitter sensitivity and the patterns of endings as described by immunocytochemistry. In contrast to our finding of numerous glutamate iontophoresis-sensitive sites, we did not detect any aspartate-responsive muscles. These data provide strong new evidence for glutamate being an endogenous transmitter at the Drosophila larval neuromuscular junction.
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PMID:Stereotypic morphology of glutamatergic synapses on identified muscle cells of Drosophila larvae. 256 66

Interactions between central opioids and catecholamines are thought to underlie the ability of adrenergic agonists both to lower blood pressure and alleviate certain symptoms of opiate withdrawal. We examined the cellular substrate for interactions between neurons containing enkephalin-like opioid peptides and catecholamines in cardiovascular portions of the medial nuclei of the solitary tracts (m-NTS) of adult rats. Single sections were dually labeled using a double-bridged peroxidase method for the localization of a monoclonal leucine (Leu5)-enkephalin-antibody and immunoautoradiography for the localization of polyclonal antibodies against the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH). Light microscopy revealed a few perikarya and numerous varicosities containing Leu5-enkephalin-like immunoreactivity (LE-LI). These were distributed among TH-labeled perikarya and processes throughout the rostrocaudal NTS. Electron microscopy of the m-NTS at the level of the area postrema further established the single as well as dual localization of TH and LE-LI in individual perikarya, dendrites, and axon terminals. Silver grains indicative of TH-labeling were usually distributed throughout the cytoplasm, whereas the peroxidase reaction product for LE-LI was localized principally to large (80-150 nm), dense-core vesicles. Immunoautoradiographic labeling for TH was detected in 118 terminals within a series of sections containing 183 terminals with LE-LI. Of these, 26% of the TH-labeled terminals and 32% of the enkephalin-containing terminals formed symmetric synapses with unlabeled dendrites, while only 7% of each type formed symmetric synapses with TH-labeled dendrites. In favorable planes of sections, the unlabeled as well as TH-labeled dendrites received convergent input from both types of terminals. A few of the remaining terminals that contained either TH or LE-LI formed asymmetric junctions with unlabeled distal dendrites; the others were without recognizable synaptic specializations within the plane of section. Approximately 20% of the TH-labeled terminals and 6% of the terminals containing LE-LI were dually labeled for both antibodies. These were invested with astrocytic processes characterized by bundles of intermediate filaments. We conclude that within cardiovascular portions of the m-NTS, opioid peptides and catecholamines contained within the same or separate terminals modulate the activity of target neurons through direct symmetric, probably inhibitory, synaptic junctions and may additionally modulate the activity of neighboring astrocytes through exocytotic release from large dense-core vesicles.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Ultrastructural basis for interactions between central opioids and catecholamines. II. Nuclei of the solitary tracts. 256 12


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