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 injection of the L7 dorsal root ganglion with 3H-leucine, fast axoplasmic transport carries some 3--5 x more labeled materials down the sensory fibers branches entering the sciatic nerve as compared to the dorsal root fiber branches of the neurons. Freeze-substitution preparations taken from the two sides of the lumbar seventh dorsal root ganglia of cats and monkeys showed little difference in the histograms of nerve fiber diameters of the sensory nerve fiber branch of these neurons as compared to the dorsal root fiber branches. A similar density of microtubules and of neurofilaments in the dorsal root and sensory nerve fiber branches over a wide range of fiber diameters was found in electron micrograph preparations. In the absence of an anatomical difference in the fibers to account for the asymmetrical outflow, a functional explanation based on the transport filament model was advanced.
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PMID:Routing of transported materials in the dorsal root and nerve fiber branches of the dorsal root ganglion. 8 50

The efferent projections of the medial geniculate nucleus (MG) and its adjacent nuclei to the basal ganglia were studied in the rat by the antero- and retrograde tracing methods. Injections of wheat germ agglutinin conjugated to horseradish peroxidase into the caudal parts of the striatum and globus pallidus produced retrograde neuronal labeling in the medial division of the MG (MGm) and its adjacent structures including the suprageniculate, posterior intralaminar and peripeduncular nuclei, and substantia nigra pars lateralis. Injections of [3H]leucine into the MG and its surroundings resulted in anterograde labeling not only in the striatum but also in the globus pallidus. The resulting labeling was distributed exclusively in the caudal parts of these two nuclei. The electron microscopic autoradiography showed preferential radiolabeling of terminals and myelinated axons in both the globus pallidus and striatum. Labeled terminals in the pallidum mostly made symmetrical synapses on somata and major dendrites, while labeled terminals in the striatum established asymmetrical synapses on dendritic spines. These morphological differences in the synapses of the efferent systems originating from the MGm and its surrounding region suggest functional/chemical differentiations at their target sites in the basal ganglia.
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PMID:Ultrastructural morphology of projections from the medial geniculate nucleus and its adjacent region to the basal ganglia. 138 84

Soluble Leu-beta-naphthylamide hydrolysing activity (arylamidase activity) was assayed in retina, superior cervical ganglia, several brain areas and serum of adult male rats, at different time points of a 12:12h light:dark cycle (from 7h to 19h light). The results demonstrated a left or right biased asymmetrical distribution of this activity depending on the time point studied: While the levels of activity were significantly higher in the left retina than in the right one at 10h of the light period, these were predominant in the right side, at 01h of the dark period. In addition, this activity was higher in the left hypothalamus at 13h of the light period. No asymmetries were disclosed in the rest of time points and structures studied. On the other hand, this activity demonstrated a diurnal variation in the left anterior hypothalamus and total posterior hypothalamus but no periodic variation was evidenced in right anterior hypothalamus or the rest of zones studied. These results may reflect the role of this activity regulating the functional status of its susceptible endogenous substrates.
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PMID:Circadian rhythm in Leu-beta-naphthylamide hydrolysing activity in selected photoneuroendocrine areas of adult male rats. 181 39

The dorsal nucleus of the lateral lemniscus (DNLL) and its connections constitute one of the ascending auditory pathways to the inferior colliculus. One notable feature of this nucleus is the heavy commissural connections between DNLL on opposite sides of the midbrain. These commissural connections may have a significant impact on the ascending pathway. In this study, the fine structure of DNLL in the cat and its commissural connections were examined. Both anterograde and retrograde transport methods were used simultaneously at the EM level. Injections of 3H-leucine mixed with WGA-HRP were made in one DNLL. After axonal transport, EM autoradiographic methods were used to identify the anterogradely labeled axonal endings from the opposite DNLL. In the same location, retrogradely labeled neurons with crossed connections were identified with HRP histochemistry. Two types of axonal endings were found in DNLL, those with round synaptic vesicles forming asymmetrical synaptic junctions and those with pleomorphic vesicles and symmetrical synapses. Both types were equally common. However, only endings with pleomorphic vesicles were labeled after injections in the contralateral DNLL. The labeled endings from the opposite DNLL appeared to represent a homogeneous population, even though a number of variations in the 2 types of endings were found. Labeled endings were presynaptic to all parts of neurons in DNLL, but a large proportion of the synapses were on cell bodies and large dendrites. Two patterns of nuclear morphology and distribution of rough endoplasmic reticulum were identified and may represent different cell types. Examples of both cell types were observed to project to the contralateral side and received labeled synaptic endings. The major finding of this study is that the crossed connections between DNLL exhibit the morphology associated with inhibitory function. Since neurons in DNLL are thought to use GABA as a neurotransmitter, the crossed connections could provide inhibitory inputs to DNLL on each side. Since some neurons receive numerous axosomatic inputs from the contralateral DNLL and also project to the opposite side, they may participate in direct reciprocal, inhibitory connections between the nuclei. Crossed inhibitory connections in the DNLL pathway may be important in regulating the flow of ascending auditory information.
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PMID:An EM study of the dorsal nucleus of the lateral lemniscus: inhibitory, commissural, synaptic connections between ascending auditory pathways. 292 87

The projections of the nucleus raphe magnus (NRM) and the immediately adjacent reticular formation were studied in the macaque monkey following injections of the rostroventral medulla with 3H-leucine and examination of the resultant labeled axons and terminals by light and electron microscopic autoradiography. Five monkeys had accurately placed injections, which resulted in fiber pathway labeling that coursed caudally, laterally, and dorsally to project to laminae I, II, and V of subnucleus caudalis of the trigeminal and then traveled in the dorsolateral funiculus of the cord and terminated in similar laminae of the spinal dorsal horn at cervical levels. The pathway was only lightly labeled caudal to the cervical enlargement and could not be readily discerned above background in the thoracic or lumbar cord. Electron microscopy revealed that axons and terminals serving this system constitute a heterogeneous population. Large-diameter myelinated axons (3-6-micron diameter), small myelinated axons (0.75-3-micron diameter), and clusters of nonmyelinated axons were labeled. Terminals in laminae I, II, and V contained mixtures of clear round and granular vesicles or clear pleomorphic and granular vesicles or formed the central element in synaptic glomeruli. The labeled profiles formed asymmetrical or symmetrical synapses on medium and small dendrites; labeled axosomatic synapses were not observed. In rare instances there were contacts between labeled profiles and vesicle-containing structures, which were probably dendritic, but whether the NRM axon was pre- or postsynaptic to such structures could not be determined. It was concluded that the NRM in the monkey is organized in a manner quite similar to that previously described in the cat. The wide variety of fiber types and synaptic terminals serving this system suggests that different classes of neurons participate in it, probably using several transmitter substances that result in varying postsynaptic effects on neurons located in the trigeminal complex and dorsal horn.
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PMID:Bulbospinal projections in the primate: a light and electron microscopic study of a pain modulating system. 374 18

A quantitative electron microscopic (EM) study combining the anterograde intra-axonal transport of radioactive amino acids and the retrograde intra-axonal transport of the enzyme horseradish peroxidase (HRP) was performed in the magnocellular red nucleus of the rat to obtain anatomical evidence as to whether there is a direct projection from the cerebellar nucleus interpositus to the cells in the red nucleus that give rise to the rubrospinal tract. Large asymmetrical synaptic terminals were radioactively labeled in the magnocellular red nucleus following injections of [3H]leucine into the cerebellar nucleus interpositus. In these same animals, the postsynaptic target neurons were labeled with HRP granules after injection of this substance in the rubrospinal tract. A quantitative analysis showed that more than 85% of the large and giant neurons in the magnocellular red nucleus were labeled with HRP granules and also received synaptic contacts from radioactively-labeled terminals. Thus, it can be concluded that in the rat, afferents from the cerebellar nucleus interpositus establish asymmetrical synaptic contacts with large and giant rubrospinal neurons, thus confirming and extending the previous physiological evidence of such direct monosynaptic connections.
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PMID:Anatomical evidence for direct fiber projections from the cerebellar nucleus interpositus to rubrospinal neurons. A quantitative EM study in the rat combining anterograde and retrograde intra-axonal tracing methods. 616 12

Following symmetrical bilateral infusion of D-glucose into the basal ventromedial hypothalamus (BVMH), using Alzet minipumps (1 microliter/h of 10% D-glucose for 6 days), average daily food intake was reduced by 27% for the period of treatment. Symmetrical bilateral infusions into the posterior medial hypothalamus had a transitory effect on feeding, as did asymmetrical and unilateral infusions. Infusion of L-glucose into the BVMH did not yield a chronic reduction in food intake. Included in the infused solutions were tracer amounts of [14C]glucose, [14C]proline or [14C]leucine to permit radioautographic estimations of infusate dispersal in the brain and axonal transport patterns from the infusion sites. Infusions were generally well-restricted to 1-1.5 mm of the cannulae tips, and descending transport of amino acids was highest in substantia nigra and midline structures of the mesencephalon and pons including central gray, ventral tegmental area, raphe and ventral tegmental nuclei. These results provide evidence for an energy intake regulatory mechanism situated in the BVMH whose outputs may modulate activity in the substantia nigra and midline brain stem areas.
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PMID:D-glucose infusions into the basal ventromedial hypothalamus and feeding. 617 Dec 96

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

The subnuclear organization of rat interpeduncular nucleus (IPN) has been examined by light microscopy following staining with Nissl and Holmes methods, 3H-leucine autoradiography, acetylcholinesterase (AChE), and cytochrome oxidase histochemistry on plastic sections stained with toluidine blue, and by electron microscopy. Three unpaired and four paired subnuclei are recognized. The rostral subnucleus is heavily stained for AChE, which clearly delineates its borders. It is distinguished ultrastructurally by two types of synapses on dendrites, and two on perikarya. Of the former, one type is formed by presynaptic processes which contain spherical and dense-cored vesicles and make asymmetrical contacts. Dense-cored vesicles are observed in many of the postsynaptic dendrites. A second type has presynaptic processes containing small, pleomorphic vesicles which make symmetrical contacts. Synapses on perikarya are found in the rostral, central, intermediate, lateral, and interstitial subnuclei. The dorsal subnucleus is continuous with the serotonin-containing B8 cells. The central subnucleus is distinguished by longitudinally oriented medial habenular axons separating palisades of cell bodies. These axons, which also traverse the intermediate subnuclei, form en passant S synapses with small dendrites of the central subnucleus. The intermediate subnuclei react faintly for AChE and intensely for cytochrome oxidase. They contain crest synapses formed by two habenular afferents, one from each medial habenula, which contact a narrow dendritic process en passant. The lateral subnuclei react intensely for AChE and have ultrastructural features similar to the rostral subnuclei. The interstitial subnuclei lie within each fasciculus retroflexus as it enters IPN. The small dorsal lateral subnuclei are evident by light microscopy.
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PMID:The subnuclear organization of the rat interpeduncular nucleus: a light and electron microscopic study. 632 69

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


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