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)

Sections of the cat's visual cortex were stained by an antiserum to glutamate decarboxylase using the peroxidase-antiperoxidase method; they were then impregnated by the section Golgi procedure and finally the Golgi deposit was replaced by gold. Neurons containing glutamate decarboxylase immunoreactivity were found in all layers of the visual cortex, without any obvious pattern of distribution. Fifteen immunoreactive neurons were also Golgi-impregnated and gold-toned, which enabled us to study the morphology and synaptic input of identified GABAergic neurons. These neurons were found to be heterogeneous both with respect to the sizes and shapes of their perikarya and the branching patterns of their dendrites. All the immunoreactive, Golgi-impregnated neurons had smooth dendrites, with only occasional protrusions. The synaptic input of glutamate decarboxylase-immunoreactive neurons was studied in the electron microscope. Immunoreactive neurons received immunoreactive boutons forming symmetrical synapses on their cell bodies. The Golgi-impregnation made it possible to study the input along the dendrites of immunoreactive neurons. One of the large neurons in layer III whose soma was immunoreactive was also Golgi-impregnated: it received numerous non-immunoreactive asymmetrical synaptic contacts along its dendrites and occasional ones on its soma. The same neuron also received a few boutons forming symmetrical synaptic contacts along its Golgi-impregnated dendrites; most of these boutons were immunoreactive for glutamate decarboxylase. Glutamate decarboxylase-immunoreactive boutons were also found in symmetrical synaptic contact with non-immunoreactive neurons that were Golgi-impregnated. A small pyramidal cell in layer III was shown to receive several such boutons along its somatic membrane. It is concluded that the combination of immunoperoxidase staining and Golgi impregnation is technically feasible and that it can provide new information. The present study has shown that there are many morphologically distinct kinds of aspiny GABAergic neurons in the visual cortex; that the predominant type of synaptic input to the dendrites of such neurons is from boutons forming asymmetrical synapses, but that some of the GABAergic neurons also receive a dense symmetrical synaptic input on their cell bodies, and occasional synapses along their dendrites, from the boutons of other GABAergic neurons. These findings provide a morphological basis, firstly, for a presumed powerful excitatory input to GABAergic interneurons and, secondly, for the disinhibition which has been postulated from electrophysiological studies to occur in the cat's visual cortex.
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PMID:The section-Golgi impregnation procedure. 2. Immunocytochemical demonstration of glutamate decarboxylase in Golgi-impregnated neurons and in their afferent synaptic boutons in the visual cortex of the cat. 619 75

The projection from the retina to the controlateral superior colliculus was studied light and electron microscopically by means of anterogradely transported horseradish peroxidase and tetramethylbenzidine histochemistry as well as light microscopically by experimental degeneration and [3H]-leucine autoradiography. Labeled boutons were found in stratum zonale (SZ) and in stratum griseum superficiale (SGS), but not in stratum opticum (S0). The number of boutons was maximal in a narrow zone in SZ about 25 to 100 micron below the surface. The labeled boutons contained numerous round vesicles and predominantly pale mitochondria. They usually formed asymmetrical synapses and contacted dendrites or boutons. Occasionally, labeled boutons were observed whose cytological features were different from those generally associated with retinotectal axons. In general, labeled boutons in SZ contained fewer mitochondria than those from SGS. Labeled myelinated axons were found throughout SGS, in the lowest part of SZ, and in SO. In upper and middle SGS they were small while in lower SGS and SO also large fibers were found.
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PMID:Retinotectal terminals in the superior colliculus of the rabbit: a light and electron microscopic analysis. 620 May 16

Thalamic projection neurons represent a major source of nociceptive information from the dorsal horn to higher centers of the neuraxis. The synaptic relationship between thalamic projection neurons and the opioid peptide enkephalin (ENK) was examined at the light (LM) and ultrastructural (EM) level using the combined techniques of retrograde transport of horseradish peroxidase and ENK immunocytochemistry. Utilizing two different chromogens to develop the peroxidase reaction product, the two labeled neural elements could be readily distinguished at the LM level in the same tissue section. In the medullary, cervical, and lumbar levels of the dorsal horn of both the cat and monkey, at least 30% of the thalamic projection neurons in lamina I were observed at the LM level to be contacted by ENK-immunoreactive varicosities. In lamina V, approximately 50% of the thalamic projection neurons received ENK contacts. Since some neurons were not observed to receive a dense ENK innervation on their somata and proximal dendrites, these data suggest that there may be different functional types of thalamic projection neurons. At the EM level, the ENK-immunoreactive varicosities were observed to form asymmetrical synaptic contacts on the labeled somata and proximal dendrites of the projection neurons. In all cases, the ENK varicosities were morphologically similar and contained round or oval agranular vesicles and a few dense-core vesicles. These observations suggest that ENK acts to a substantial degree on postsynaptic opiate receptors located on thalamic projection neurons.
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PMID:Demonstration of postsynaptic opioid modulation of thalamic projection neurons by the combined techniques of retrograde horseradish peroxidase and enkephalin immunocytochemistry. 620 11

A perfused, isolated retina-eyecup preparation of the rabbit was utilized to correlate the physiology and morphology of horizontal cells. Neurons were physiologically characterized by intracellular recording techniques and subsequently stained with intracellular iontophoretically injected horseradish peroxidase for morphological identification. Three types of rabbit horizontal cell recordings have been differentiated, based on variations in response waveform, amplitude-intensity properties, and area summation characteristics. These three types have been unequivocally associated with the axonless A-type horizontal cells and the somatic and axon terminal endings (each displaying its own distinct physiology) of B-type horizontal cells first described in studies using Golgi-impregnation techniques (Fisher and Boycott, '74). In addition, the sizes of A-type horizontal cells were found to be directly related to their retinal eccentricities from the optic desk. However a unique subclass of A-type cells has been discovered (elongated or Ae type) which displayed the largest dendritic field of any cells studied here, yet had the smallest eccentricities--within 1.4 mm of the optic disk. Moreover, elongated A-type cells exhibited long asymmetrical dendritic fields which were oriented parallel with the visual streak. The unique asymmetry and orientation of these cells suggests that they may have orientation-biased receptive field properties. Physiological evidence for an orientation-biased horizontal cell is presented in support of this notion.
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PMID:A physiological and morphological study of the horizontal cell types of the rabbit retina. 628 77

The dopaminergic innervation of the rat lateral septum has been investigated at ultrastructural level by immunocytochemistry using the unlabelled peroxidase-anti-peroxidase method with anti-dopamine antibodies. The specificity of the reaction has been carefully checked by immunological and histochemical controls. A strong immunoreaction was observed in fibres of the lateral septum as well as in their cells of origin in the ventral tegmental area. In the lateral septum, dopamine-immunoreactive fibres were localized in two distinct areas. A first area, located ventrally in the anterior part of the septum was characterized by a high density of immunoreactive varicosities with barely visible intervaricose segments. A more dorsal area, extending throughout the anteroposterior region of the septum, was characterized by immunoreactive fibres in pericellular arrangements. Electron microscopic observations revealed no difference in the ultrastructure of dopamine-immunoreactive profiles in the different areas. Reaction product was found in vesicles, linked to microtubules and in the cytoplasm. Three types of vesicles were seen: (i) small vesicles (30-50 nm) with varying intensity of immunoreaction, filling up the varicosities; (ii) rare large clear vesicles (50-80 nm) with no internal immunoreaction; (iii) very rare large dense vesicles (50-100 nm) with a strong dopamine immunoreactivity. Labelled profiles were observed in clearly defined asymmetrical synaptic contacts with somata and dendrites. Due to the lack of previous work dealing with the use of anti-dopamine antibodies for electron microscope immunocytochemistry, our observations are compared to previous data obtained by more indirect labelling techniques.
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PMID:Ultrastructural immunocytochemical study of the dopaminergic innervation of the rat lateral septum with anti-dopamine antibodies. 639 26

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 anterograde horseradish peroxidase (HRP) technique was used to identify ascending intratrigeminal axons originating from neurons in the medullary dorsal horn (MDH) which terminate in trigeminal nucleus oralis (Vo). HRP injections into the MDH labeled two populations of axons ascending ipsilaterally within the spinal trigeminal nucleus. The first population was composed of parent branches which each gave off a single branching collateral strand to Vo as they ascended. These collaterals were characterized by boutons filled with small, round synaptic vesicles and forming asymmetrical synaptic contacts with large diameter dendritic shafts. The second axonal population was made up of parent branches which terminated directly in Vo. Their short terminal strands were distinguished by axonal endings containing pleomorphic synaptic vesicles and forming symmetrical synaptic junctions with small diameter dendritic shafts and spines.
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PMID:Termination in trigeminal nucleus oralis of ascending intratrigeminal axons originating from neurons in the medullary dorsal horn: an HRP study in the rat employing light and electron microscopy. 669 29


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