Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After injecting horseradish peroxidase into the thalamic regions around the paraventricular thalamic nucleus (Pv) in the rat, small neurons in the globus pallidus (GP) were labeled retrogradely with the enzyme. After injecting [3H]leucine into the GP, terminal labeling was autoradiographically observed in the Pv bilaterally with an ipsilateral dominance. These terminals in the Pv were shown by electron microscopic autoradiography to make asymmetrical synaptic contacts upon small dendrites of Pv neurons.
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PMID:Direct projections from the globus pallidus to the paraventricular nucleus of the thalamus in the rat. 652 8

The retrograde horseradish peroxidase technique was used to: (1) identify and assess the overall morphology of large neurons in the ventrolateral portion (VL) of rat trigeminal nucleus oralis projecting to cervical, thoracic and lumbosacral levels of the spinal cord; and (2) characterize the synaptic endings terminating on their dendrites. The morphology of large VL neurons projecting to all spinal levels is similar. They have 25-50 microns pyramidal-shaped somata which emit 3-6 primary dendrites. These primary dendrites give rise to spherical to elliptical-shaped dendritic arbors measuring up to 700 microns in diameter. Labeled axons enter either a deep axon bundle or the medial portion of the spinal V tract. Dendrites of labeled neurons are contacted by axonal endings of 3 types. The most numerous endings are filled with clear, spherical synaptic vesicles and usually form single asymmetrical contacts along the entire length of dendritic shafts. Synapsing less frequently on dendritic shafts are endings containing pleomorphic synaptic vesicles and forming single symmetrical synaptic contacts. The least frequently encountered synaptic terminal contains flattened synaptic vesicles and makes a single symmetrical synaptic contact with a dendritic shaft.
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PMID:Axonal endings terminating on dendrites of identified large trigeminospinal projection neurons in rat trigeminal nucleus oralis. 652 24

The projection from the striate cortex to the superior colliculus was studied light- and electron microscopically by means of anterogradely transported horseradish peroxidase and tetramethylbenzidine histochemistry. Labeled boutons were found in the stratum zonale (SZ) and in the stratum griseum superficiale (SGS), not in stratum opticum (SO). There are two maxima of frequency of labeled boutons, one in middle SGS at about 500 microns depth, and a smaller one in upper SGS at about 200 microns depth. Such a bimodal distribution of corticotectal terminals has not been described in any species before. Labeled myelinated axons were found in SGS and SO with a maximal frequency in middle SGS at about 400 microns depth. The myelinated axons in SZ, which are commonly considered to be of cortical origin, were not labeled. The labeled cortical terminals contained numerous round synaptic vesicles and predominantly dark mitochondria. They formed usually asymmetrical synapses and contacted dendrites, some of which contained synaptic vesicles. Occasionally, labeled boutons were observed which definitely did not belong to the type that is generally considered to be of cortical origin.
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PMID:Corticotectal terminals in the superior colliculus of the rabbit: a light- and electron microscopic analysis using horseradish peroxidase (HRP)-tetramethylbenzidine (TMB). 661 34

In order to classify the presynaptic elements contacting the principle class of globus pallidus neurons, electron microscopic examination of serial sections made from a medially located large globus pallidus neuron, labeled with intracellular horseradish peroxidase, was undertaken. In addition, the use of labeled and light microscopically reconstructed material allowed us to quantitatively determine the distribution of each bouton type along the soma and dendrites. Six types of presynaptic terminals contacting the labeled cell have been recognized. Type 1 endings, the most numerous (84%), make symmetrical contacts on all portions of the cell, except spines, contain large pleomorphic, and a few large dense-core vesicles. Type 2 endings are filled with small spherical-to-ellipsoidal synaptic vesicles. They make asymmetrical contacts only with higher-order dendrites and account for 12% of synaptic contacts onto the labeled neuron. Type 3 endings are large, contain sparsely distributed large pleomorphic vesicles, and make two symmetrical synapses per bouton, one onto a spine head and the other onto the underlying dendritic shaft. They are infrequent (0.2%), being found only in association with dendritic spines. Type 4 endings contain large pleomorphic synaptic vesicles and no dense-core vesicles. They make symmetrical contacts with the short primary dendrites. Type 5 endings contain a mixture of small clear pleomorphic vesicles and numerous large dense-core vesicles. They contact only the cell body and the short primary dendrites, making up 20% of somatic synaptic contacts but less than 1% of contacts onto dendrites. Type 6 boutons contain oval and flattened synaptic vesicles and establish symmetrical contacts with higher-order dendritic branches and the cell body.
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PMID:An intracellular HRP study of the rat globus pallidus. II. Fine structural characteristics and synaptic connections of medially located large GP neurons. 665 84

The ventrobasal complex (VB) of the rat thalamus contains neurons responding to non-noxious somatic stimuli as well as neurons driven exclusively by noxious stimuli. This study presents a comparison of morphological features of these two kinds of neurons. Thirteen neurons electrophysiologically characterized were impaled with the micropipette used for the recordings and intracellularly injected with horseradish peroxidase. After revealing the marker and preparation for electron microscopic procedures, 3 out of the 13 neurons were carefully studied using both the light and the electron microscope. VB neurons are stellate cells with a central rounded cell body and 6 to 10 primary dendrites which branch rapidly, giving a 'tufted' appearance. Dendrites of all orders present various types of protrusions. At the electron microscope level, 3 main kinds of synaptic profiles were observed contacting the injected neurons: small terminals with round vesicles which make asymmetrical contacts with distal dendrites; medium-sized terminals with flattened vesicles which make symmetrical contacts with dendrites of all orders and the soma; and large terminals with round vesicles which make asymmetrical contacts with primary dendrites and the soma. This study failed to reveal obvious morphological differences between functionally different VB neurons. In addition, it showed that their synaptology was apparently equivalent.
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PMID:The structural organization of the ventrobasal complex of the rat as revealed by the analysis of physiologically characterized neurons injected intracellularly with horseradish peroxidase. 672 37

In an attempt to evaluate the cellular organization and efferent projections of the nucleus tegmenti pedunculopontinus pars compacta, several experiments were performed in the rat. From measurements of neurons in the nucleus tegmenti pedunculopontinus pars compacta in Nissl-stained sections, the nucleus was observed to contain many large neurons which made it possible to demarcate this nucleus from surrounding pontomesencephalic reticular formation. Two other neuronal populations, medium and small neurons, were also seen in the nucleus tegmenti pedunculopontinus pars compacta. Detailed measurements showed that 90% by volume of all neurons in the nucleus tegmenti pedunculopontinus pars compacta were large and medium-sized neurons. After injections of [3]leucine into the nucleus tegmenti pedunculopontinus pars compacta, transported label was observed in dorsally and ventrally coursing ascending fibers. The dorsally coursing fibers entered the centrolateral nucleus and centre median-parafascicular complex of the thalamus. The ventrally coursing fibers produced accumulation of silver grains in the ventral tegmental area, substantia nigra pars compacta, subthalamic nucleus, zona incerta and lateral hypothalamus. Crossed fibers of the nucleus tegmenti pedunculopontinus pars compacta were observed sparsely at the levels of the thalamus and posterior commissure, and to a greater degree through the supraoptic commissure of Meynert. Much less anterograde labeling was seen in the equivalent terminal sites on the contralateral side of the brain. By electron microscopic autoradiography major terminal sites of axons of the nucleus tegmenti pedunculopontinus pars compacta were examined in rats injected with [3H]leucine in the nucleus tegmenti pedunculopontinus pars compacta and later injected with horseradish peroxidase in the striatum and pallidum. Statistical data showed preferential radiolabeling of terminals forming asymmetrical synaptic contact with dendrites in the centrolateral nucleus, centre median-parafascicular complex and subthalamic nucleus. Apparent terminations in the substantia nigra pars compacta proposed in earlier studies and shown in the present light microscopic autoradiograms were not supported by this ultrastructural analysis. Several radiolabeled terminals of the asymmetrical type contacting horseradish peroxidase labeled dendrites in the thalamus confirmed direct input from the nucleus tegmenti pedunculopontinus pars compacta to the thalamostriate projection neurons. [3H]choline injections into the thalamus and subthalamic nucleus produced retrograde perikaryal labeling of large neurons in the nucleus tegmenti pedunculopontinus pars compacta.
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PMID:Organization and efferent projections of nucleus tegmenti pedunculopontinus pars compacta with special reference to its cholinergic aspects. 673 60

Using a modification of the peroxidase-antiperoxidase technique, serotonin immunoreactivity was localized at the ultrastructural level in the nucleus of the solitary tract of the cat. Structures containing serotonin immunoreactivity included unmyelinated axons, varicosities (0.5 to 2 micrometers in diameter), and synaptic terminals. The serotonin-containing synaptic terminals were found less frequently than axons or varicosities. Within unmyelinated axons and varicosities, the immunoreactivity was associated mainly with large granular vesicles (80 to 150 nm). While large granular vesicles were found in all immunoreactive structures, greater numbers were observed in axons and nonsynaptic varicosities. Serial sections of several nonsynaptic serotonin-immunoreactive varicosities indicated the lack of synaptic specializations associated with these structures. In a typical section, only one or two granular vesicles were in synaptic terminals which contained numerous small clear vesicles. Serotonin-immunoreactive terminals formed asymmetrical contacts with dendrites and spines. No synaptic contacts involving immunoreactive terminals were found on cell bodies or other axonal structures. Serotonin-containing neuronal perikarya within the nucleus of the solitary tract were never observed. The abundance of nonsynaptic varicosities containing large granular vesicles suggests a possible neurohumoral role for serotonin within the feline nucleus of the solitary tract. This is discussed in relation to previous reports concerning the paucity of genuine synaptic contacts involving serotonin in other regions of the central nervous system. The presence of serotonin-immunoreactive terminals in the nucleus of the solitary tract also suggests its function as a putative neurotransmitter.
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PMID:The ultrastructural localization of serotonin immunoreactivity within the nucleus of the solitary tract of the cat. 675 49

The nucleus basalis of Meynert in the squirrel monkey exhibits numerous labeled neurons following the retrograde transport of horseradish peroxidase from occipital cortical injection sites. The typically large, often clustered, labeled cells are seen most frequently in association with the fibrous bordering structures of the substantia innominata and in the internal and external laminae of the globus pallidus. Ultrastructurally the copious cytoplasm of nucleus basalis neurons abounds with organelles. Large, vacuolated lipofuscin granules proliferate as a function of age and are not evident in younger monkeys. Approximately 4% of the somal surface is occupied by symmetrical synapses with either flat or pleomorphic vesicles. The remainder is covered mostly by neuroglial processes. Somatic spines bearing synapses are occasionally observed. In the neuropil surrounding nucleus basalis somata, the synapses onto dendrites and spines are mostly asymmetrical with large, round vesicles. Labeled nucleus basalis cells in the substantia innominata immediately lateral to the optic tract are larger and rounder than cells in the internal and external pallidal laminae. However, no remarkable ultrastructural differences were observed between nucleus basalis somata in the substantia innominata and external pallidal lamina, or between horseradish peroxidase-labeled and unlabeled large cells.
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PMID:Ultrastructure of neurons in the nucleus basalis of Meynert in squirrel monkey. 688 49

Motoneurons in the cat oculomotor nucleus have been identified electrophysiologically and stained by intracellular injection of horseradish peroxidase. Axon collateral arborizations with preterminal and terminal boutons identified by light microscopy corresponded to synaptic endings observed by electron microscopy. Despite variations in size and shape, synaptic endings showed similar ultra-structural features and established asymmetrical predominantly axodendritic synaptic contacts usually characterized by the presence of subjunctional dense bodies underlying the postsynaptic membrane densification.
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PMID:Electron microscopic observations of axon collateral synaptic endings of cat oculomotor motoneurons stained by intracellular injection of horseradish peroxidase. 705 37

The horseradish peroxidase and autoradiographic methods show that laminae I and outer II are innervated by the nucleus reticularis gigantocellularis pars ventralis, and the nucleus reticularis pontis pars ventralis. Both areas contain neurons of the indolamine type and probably account for the indolamine-like varicosities which are present within laminae I and II. Degeneration materiom the above nuclei end on small dendritic shafts and spines as well as on vesicle-filled proflies. The terminals identified formed asymmetrical contacts and contained clear as well as dense-cored vesicles. No terminals were present within glomeruli. A projection to laminae I and outer II also arises within the dorsolateral pons and several ines of evidence suggest that it is catecholaminergic. The electron microscope revealed that axons from the dorsolateral pons are fairly numerous within laminae I and II, but that terminal contacts are relatively rare. Those present are asymmetrical and alternate with intermediate-sized dendrites. They contain clumps of clear, spherical vesicles as well as larger vesicles with a variety of dense cores.
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PMID:Projections from the brain stem reticular formation to laminae I and II of the spinal cord. Studies using light and electron microscopic techniques in the North American opossum. 737 Jul 81


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