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)

The distribution of GABA-immunoreactive neurons and axonal varicosities was investigated in the hippocampal region of the rat brain by means of an indirect peroxidase immunocytochemical method with recently developed anti-GABA antibodies. The immunolabeling was found to be restricted to nervous structures: neuronal cell bodies, dendrites and axon terminals. Myelinated axons showing GABA-immunoreactivity were also observed. GABA-immunoreactive neurons were found in great number in the stratum pyramidale, the superficial part of the stratum oriens and the deep part of the stratum radiatum in the Ammon's horn. Less were found in the other regions; rare labeled cells were observed in the superficial part of the stratum radiatum and the middle part of the stratum oriens. The dentate gyrus exhibited numerous labeled cells in the granular layer, few in the hilus, rare in the molecular layer. A high density of GABA-immunoreactive terminals was found at the limit of the stratum oriens with the alveus, in the stratum pyramidale and in the stratum lacunosum. A lower density of labeled fibers was observed in the other areas. The somata and proximal dendrites of pyramidal and granular cells were encompassed by characteristic pericellular arrangements of GABA-immunoreactive varicosities. Ultrastructural observations revealed a diffuse immunoreaction product spread over the cytoplasm and the nucleus without specific relationship with the organelles, and immunoreactive aggregates in the cytoplasm. Labeled dendrites often showed enlargements displaying the immunoreaction whereas thinner segments were devoid of it. They received numerous asymmetrical synapses from unlabeled axon terminals. GABA-immunoreactive terminals were filled with small clear vesicles with immunopositive membranes and were observed in symmetrical contact with somata and dendrites.
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PMID:Gamma-aminobutyric acid-immunoreactivity in the rat hippocampus. A light and electron microscopic study with anti-GABA antibodies. 351 33

The distribution of vasoactive intestinal polypeptide (VIP) was mapped by peroxidase immunocytochemistry in the spinal cords of seven Macaca fascicularis monkeys and two cats. The animals were perfusion fixed with different chemicals. Those that were perfused with either a Zamboni fixative or 5% acrolein had significantly greater immunoreactivity outside the sacral cords; those fixed with 4% paraformaldehyde had little in nonsacral regions. VIP-like immunoreactive (VIP) axons and terminals were found in the superficial dorsal horn, reticular nucleus of lamina V, intermediomedial nucleus, and lamina X at all levels from C2 to S4; a few axons and terminals were also seen in the ventral horn. Axons were found in Lissauer's tract at all levels, and axons appeared in the dorsolateral and ventrolateral white matter at midthoracic levels; in the lumbosacral cord the number and extent of axons in the lateral and ventral white matter increased progressively in a caudal direction. VIP neurons were identified in thoracic intermediate gray lateral to the central canal and in the intercalatus (IC) and intermediolateral (IML) nuclei. Electron microscopy of the VIP terminals in laminae I and II of the cervical cord revealed they contain small round vesicles and many large granular vesicles; some are glomerular terminals and most form asymmetrical synaptic contacts onto dendrites. These results indicate VIP is much more widely distributed in the spinal cord than previously thought; VIP may be associated with both visceral thoracic and lumbosacral afferents, and with other afferents in the cervical cord; VIP neurons are present in the thoracic intermediate gray; and VIP axons in the ventral and lateral white matter indicate that the spinal cord is supplied in part by VIP sources other than primary afferents.
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PMID:VIP terminals, axons, and neurons: distribution throughout the length of monkey and cat spinal cord. 352 16

The fine structure and types of contact made by GABAergic elements in the septal nuclei were studied at the electronmicroscopic level by means of peroxidase immunocytochemistry, using anti-GABA antibodies. Observations were made on normal and colchicine-injected rats. GABA-immunoreactivity was distributed within somata, dendrites, axonal varicosities and terminals, and myelinated axons. The peroxidase reaction product was diffuse in the cytoplasm; cytoplasmic organelles were generally devoid of immunoreactivity, while showing a strong reaction on the outer surface of their membrane. GABA-immunoreactive (GABA-I) neurons were small (10 microns on average) to medium (20 microns) in size, with round or multipolar cell bodies. Additionally, labeled large (30 microns) cells were observed within the myelinated fibers of the medial septal nucleus after intraseptal administration of colchicine. No difference in the ultrastructural features and distribution of the immunoreactivity of the 2 kinds of cell was noticed, except for a higher number of synaptic contacts on large neurons of the medial septum. GABA-I cells of the medial and lateral nuclei received synapses on their soma and dendrites, made by both immunonegative and GABA-I terminals. Nonimmunoreactive boutons contacting GABA-I cell bodies were of 2 types: those containing small, clear synaptic vesicles and those that additionally contained large dense vesicles. Synaptic vesicles of GABA-I boutons were rarely labeled internally, but showed varying electron densities. Synapses made by GABA-I boutons on GABA-I or unlabeled somata and dendrites were always of symmetrical type. Synapses made by non-GABA-I boutons on GABA-I cells were either symmetrical or asymmetrical.
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PMID:An ultrastructural study of GABA-immunoreactive neurons and terminals in the septum of the rat. 354 51

GABAergic neuronal profiles in the supraoptic nucleus of the rat were immunohistochemically identified by using a purified GABA antibody with the peroxidase-antiperoxidase method. The localization of GABA-like immunoreactivity in nerve terminals on the neurosecretory neurons was examined electron microscopically. A few small GABAergic neurons were found inside the supraoptic nucleus while only a very few medium-sized ones were detected in the perinuclear zone. Intrinsic, non-GABAergic small neurons covered by GABAergic neuropil were also detected. The neuropil with GABAergic axo-somatic synapses evenly encompassed unlabeled neurosecretory perikarya throughout the supraoptic nucleus. The GABAergic system seems to inhibit both vasopressin and oxytocin cells. In this area, glia cells showed clear outlines of unlabeled somata around counter-stained nuclei. Blood capillaries in the supraoptic nucleus were only slightly covered with a GABAergic neuropil. Electron microscopic observations demonstrated the presence of GABAergic axo-somatic symmetrical and axo-dendritic asymmetrical synapses on the neurosecretory neurons. GABA-like immunoreactivity was localized on the membranes of microtubules and synaptic vesicles, on the external membranes of the mitochondria, and on the inner leaf of the presynaptic sites. Numerous pairs of non-immunoreactive synapses were arranged along these immunoreactive synapses.
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PMID:Immunohistochemical studies on the GABAergic system in the rat supraoptic nucleus using the PAP method with an application of electron microscopy. 355 72

Retinorecipient regions of the ventral lateral geniculate nucleus of the thalamus and the superior colliculus of the midbrain are linked by reciprocal axonal projections. In this study we have investigated the ultrastructural characteristics, the distribution, and the postsynaptic targets of the terminals of axons projecting to the ventral lateral geniculate nucleus from the superior colliculus. Horseradish peroxidase was injected into the superior colliculi of adult albino rats, and the Hanker-Yates method was used to visualize anterogradely and retrogradely transported peroxidase in the ventral lateral geniculate nuclei 24 hours following the injection. Labelled terminals were found in the lateral and ventrolateral parts of the external division of the ipsilateral ventral lateral geniculate nucleus. The labelled terminals were confined to areas of simple, nonglomerular neuropil. They were 0.45-1.5 micron in diameter; contained small, dark mitochondria and spherical synaptic vesicles; and established Gray type I (asymmetrical) synaptic contacts with the dendritic shafts, dendritic spines, and occasionally cell bodies of cells with the ultrastructural characteristics of projection cells. A few labelled terminals established synaptic contact with retrogradely labelled cells. Thus, in the rat, the projection from the superior colliculus gives rise to a uniform population of axon terminals in the nonglomerular neuropil of the lateral portion of the ventral lateral geniculate nucleus, which synapse with, and are probably excitatory to, geniculocollicular and other projection cells.
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PMID:Ultrastructural organisation of the projection from the superior colliculus to the ventral lateral geniculate nucleus of the rat. 357 17

The synaptic organization of the feline entopeduncular nucleus was studied electron microscopically. After horseradish peroxidase injections into the ventral anterior and ventral lateral nuclear complex of the thalamus, normal axon terminals synapsing with entopedunculothalamic projection neurons were classified into four types on the basis of the size and shape of synaptic vesicles in them, and types of the postsynaptic membrane differentiation. Type I and type II axon terminals were characterized by symmetrical synaptic contacts, and large ovoid or small ovoid synaptic vesicles, respectively. Type II axon terminals were further classified into two subtypes as to their sizes: one was small (IIa), the other large (IIb). Type III and type IV axon terminals were characterized by asymmetrical synaptic contacts, and large ovoid or small ovoid synaptic vesicles, respectively. To determine the origin of each type of terminal, electrolytic lesions of the caudate nucleus or the subthalamic nuclear region were combined with horseradish peroxidase injections into the thalamus or the subthalamic nuclear region. After electrolytic lesions of the caudate nucleus, degeneration was seen in type I axon terminals contacting entopedunculothalamic projection neurons. Following electrolysis or horseradish peroxidase injection into the subthalamic nuclear region, type IIa and type IV axon terminals showed degenerations or horseradish peroxidase labelling. Such terminals also synapsed with entopedunculothalamic projection neurons. It was demonstrated that these projection neurons relay the striatal or subthalamic inputs directly to the thalamus. After horseradish peroxidase injection into the thalamus, many labelled type II axon terminals were observed to synapse with entopedunculothalamic projection neurons. Type III axon terminals were left unchanged throughout these experiments. In addition, the entopeduncular neuron was observed to receive convergent inputs from both the caudate nucleus and probably the subthalamic nucleus. Axoaxonal synapses were also found to be involved in the synaptic triad. These results indicate that type I axon terminals originate from the caudate nucleus, part of type IIa and type IV axon terminals originate from the subthalamic nucleus or caudal to the subthalamic nuclear region, and part of type IIa and type IIb terminals come from intrinsic axon collaterals.
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PMID:Synaptic organization of the cat entopeduncular nucleus with special reference to the relationship between the afferents to entopedunculothalamic projection neurons: an electron microscope study by a combined degeneration and horseradish peroxidase tracing technique. 360 Oct 64

This anterograde horseradish peroxidase study examines the morphology and synaptic connections of a population of primary axons which terminate in the dorsal one-half of the border zone (BZ) of rat trigeminal nucleus oralis. Unmyelinated parent fibers in the spinal V tract enter BZ directly and each terminate by continuing as a sparsely branched, long caudally directed strand containing several axonal endings. Primary endings lie in glomeruli where each forms an asymmetrical synapse on a central dendrite. Other glomerular components include two types of non-primary endings. One contains flattened synaptic vesicles, and forms a symmetrical synapse on either the primary ending or the central dendrite, while the other contains pleomorphic synaptic vesicles and establishes a symmetrical synapse on the central dendrite.
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PMID:Morphology and synaptic connections of unmyelinated primary axons in the border zone of rat trigeminal nucleus oralis. 377 35

This study demonstrates the termination of ascending tract of Deiters' (ATD) axons on ipsilateral medial rectus (MR) motoneurons. Horseradish peroxidase (HRP) was iontophoretically injected into ATD axons which were recorded in the MR motoneuron pool of the oculomotor nucleus. MR motoneuron cell bodies were identified by retrograde transport of HRP injected into MR muscles in the orbit. ATD axons were identified by Type I responses to horizontal rotation, monosynaptic responses on stimulation of the ipsilateral labyrinth, and no response on contralateral labyrinth or contralateral abducens nucleus or on ipsilateral MR nerve stimulation. Light microscopic examination showed the main stem axons to be lateral to the medial longitudinal fasciculus, and terminal boutons were in contact with ipsilateral identified MR motoneurons (Furuya and Markham: Exp. Brain Res. 43: 289-303, 1981). Light microscopy and semi-thin sections showed boutons of ATD in contact with identified MR motoneuron cell bodies and proximal dendrites. The electron micrographs (EM) showed the HRP-injected ATD axons have synapses on MR motoneurons. ATD boutons made axosomatic and axodendritic synapses on MR motoneurons. The boutons contained numerous spheroidal synaptic vesicles. Several examples showed clear asymmetrical post-synaptic membrane specialization. This confirms the synaptic connection between horizontal canal activated elements in the ATD and MR motoneurons.
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PMID:Synaptic connections of horizontal canal mediated ascending Deiters tract axons on medial rectus motoneurons in cat. 382 46

Injections of horseradish peroxidase (HRP) or wheat-germ agglutinin-horseradish peroxidase (WGA-HRP) into the nucleus reticularis parvocellularis (RPc) produced anterograde labeling of axon terminals within the hypoglossal nucleus. Based on morphological parameters of vesicle population, membrane specializations, and postsynaptic articulations, two types of axon terminals derived from neurons in RPc end on hypoglossal neurons. More than half of the terminals contained spherical vesicles (S-type), established asymmetrical membrane specializations and contacted proximal and medium-sized dendrites. The remaining labeled terminals had flattened vesicles (F-type), symmetrical membrane densities and apposed medium and small dendrites. The morphological differences expressed in the two types of terminals may reflect physiological and/or pharmacological differences in the action of RPc neurons on motoneurons in the hypoglossal nucleus.
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PMID:The ultrastructural identification of reticulo-hypoglossal axon terminals anterogradely labeled with horseradish peroxidase. 383 52

The projections from the deep cerebellar nuclei and the sensorimotor cortex to the red nucleus were studied in the rat using anterograde transport of horseradish peroxidase conjugated with wheat germ agglutinin (HRP-WGA). The anterogradely transported HRP-WGA was visualized ultrastructurally by using a modification of the tetramethylbenzidine (TMB) histochemical technique of Carson and Mesulam ('82). Following injection of HRP-WGA into the sensorimotor cortex, ultrastructural examination of anterograde labeling in the ipsilateral red nucleus revealed labeled synaptic terminals located on small-diameter dendrites of the parvocellular region. These terminals made asymmetrical contacts and contained round vesicles. HRP-WGA placement in the nucleus lateralis resulted in anterograde labeling of synaptic terminals which made asymmetrical contacts with small- to medium-sized dendrites of the parvocellular red nucleus. Similar placements in the nucleus interpositus gave rise to anterograde labeling of synaptic terminals which made asymmetrical contacts with somata and proximal dendrites of magnocellular neurons. In addition, retrograde labeling of magnocellular neurons was also observed following HRP-WGA placements in the nucleus interpositus. Anterogradely labeled interpositorubral synaptic terminals were located on retrogradely labeled rubrocerebellar neurons. The rat red nucleus thus receives topographically organized afferents which are characterized by their specificity in location at the cellular level.
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PMID:An HRP-TMB ultrastructural study of rubral afferents in the rat. 384 Jan 84


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