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

The distribution and morphology of the substance P-like immunoreactive (SP-IR) fibres and terminals in the rat ventromedial mesencephalic tegmentum (VMT) were studied using qualitative and quantitative immunohistochemical methods at light and electron microscopic levels. All five component nuclei of the VMT were examined and the size, number and density of immunoreactive terminals determined. The SP-IR fibres were distributed heterogeneously within the VMT. Under the electron microscope, SP-IR axon terminals contained both clear and dense-cored vesicles and made both symmetrical and asymmetrical synapses. The ultrastructure of the SP-IR terminals appeared to differ between nuclei. Small, clear vesicle terminals made symmetrical synaptic junctions with small calibre dendrites in the paranigral nucleus while large, clear and dense-cored vesicle terminals made asymmetrical junctions with somata and large calibre dendrites in the interfascicular nucleus. Quantitative differences between the VMT nuclei were also seen in the density of SP-IR terminals, the paranigral nucleus contained the highest density and the rostral linear nucleus the lowest. A comparison between the number of SP-IR terminals and the total number of axon terminals in the VMT reveals that the majority of all terminals in the paranigral nucleus were SP-IR, as well as the majority of axosomatic synapses in the interfascicular nucleus. These regional differences in the SP-IR innervation suggest that substance P and related peptides may perform several specific functions within the VMT and therefore have a more variable influence on this region than was previously thought.
 ...
PMID:Substance P-like immunoreactive fibres in the ventromedial mesencephalic tegmentum of rat. 246 61

The 'mirror technique' was applied in immunoelectron microscopy to demonstrate the synaptic relationship between neuronal structures containing catecholamines and substance P in the caudal part of nucleus of the solitary tract in the rat, using antisera against tyrosine hydroxylase and substance P. Substance P-immunoreactive axon terminals were shown to make two types of synaptic contacts (asymmetrical and symmetrical) with catecholaminergic neurons. It is concluded that substance P afferents can directly affect catecholaminergic neurons in this nucleus via synapses.
 ...
PMID:Synaptic interaction between catecholaminergic neurons and substance P-immunoreactive axons in the caudal part of the nucleus of the solitary tract of the rat: demonstration by the electron microscopic mirror technique. 258 57

The cholinergic synapses of the rat interpeduncular nucleus (IPN) were demonstrated by immunostaining that utilized a monoclonal antibody directed against choline acetyltransferase. The rostral, central, intermediate and lateral subnuclei of the IPN each contained a single type of immunoreactive terminal. Immunoreactivity was localized to synaptic vesicle membranes (especially at the contact zones), and longitudinal microtubules in preterminal portions of axons. Terminals were identified by comparison to previous studies of the synaptic organization of the IPN. In the rostral subnucleus, the immunoreactive terminals were characterized by their content of spherical vesicles, 45 nm in diameter, intermixed with moderate numbers of dense-cored vesicles, 75-100 nm in diameter. These terminals formed asymmetrical contacts. They correspond to the more numerous of the two types of axodendritic terminals described in this subnucleus, i.e. those which degenerate after lesions of the habenula. The moderate number of immunoreactive terminals in the lateral subnucleus contained pleomorphic vesicles, 30-45 nm in diameter. Up to three of these formed symmetrical contacts with individual dendrites, which ranged in diameter from 0.35 to 0.55 micron. The other types of axodendritic terminal in this subnucleus, which often contacted the same dendrites, were unstained. These latter terminals have been interpreted as being those which contain substance P. The immunoreactive terminals in the diameter, and formed markedly asymmetrical en passant contacts with small dendritic processes or spines. The immunoreactive terminals in the intermediate subnucleus had the same presynaptic and contact morphology. Many were clearly crest synapses. The remainder appeared to be such, but seen only partially within the plane of section. In the intermediate subnucleus there were up to several hundred immunostained terminals per grid square in some sections. These findings are consistent with the existence of a dense cholinergic projection to the IPN. The habenular region, are shown to crest and S synapses, both of which generate after lesions of the cholinergic innervation of other subnuclei of the IPN increases understanding of the relation of cholinergic to other transmitters localized to various portions of this nucleus.
 ...
PMID:Choline acetyltransferase immunoreactivity is localized to four types of synapses in the rat interpeduncular nucleus. 391 48

The release of transmitters was studied in various structures of the basal ganglia in cats implanted with several push-pull cannulas. Local depolarization enhanced Met-enkephalin release in the globus pallidus. Activation of striatonigral substance P(SP) neutrons stimulated the transmitter release from terminals. Unilateral electrical stimulation of the caudate nucleus evoked GABA release in both substantia nigrae and pallidoentopeduncular nuclei. The unilateral facilitation or interruption of nigral SP transmission modified dopamine (DA) release in the ipsilateral caudate nucleus in contrast, modifications of GABAergic or glycinergic nigral transmissions induced bilateral symmetrical effects, whereas bilateral asymmetrical changes in DA release in the two caudate nuclei were seen during the unilateral modification of nigral DA transmission. Changes in the dendritic release of DA induced changes in serotonin release both in the substantia nigra and in the ipsilateral caudate nucleus. Finally, it will be shown that acetylcholinesterase can be released from the substantia nigra and the caudate nucleus through processes dependent on nerve activity.
 ...
PMID:In vivo release of transmitters in the cat basal ganglia. 616 43

The main neuronal systems containing substance P are summarized on the basis of immunohistochemical evidence. The substance P striatonigral projection is one of the most conspicuous of these. Electron microscopic studies using the peroxidase-antiperoxidase technique reveal some heterogeneity in the substance P-immunostained material in the substantia nigra. Immunoreactivity for the peptide is found in terminals establishing both symmetrical and asymmetrical synapses with substantia nigra dendrites. Substance P immunoreactivity in the substantia gelatinosa of the trigeminal nerve and in the skin of the trigeminal territory was found to be depleted after sensory denervation. Electron microscopy showed that in this area of the rat brain substance P-immunoreactive elements are largely associated with dendrites and establish asymmetrical axo-dendritic synapses. Substance P-immunoreactive terminals synapsing with presynaptic dendrites were also observed (i.e. dendrites that themselves are presynaptic to other dendrites). The origin of substance P-containing fibres in the prevertebral ganglia has been investigated in the guinea-pig by combining surgical procedures and immunohistochemistry. Only procedures which disconnected dorsal root ganglia from prevertebral ganglia depleted substance P immunofluorescence in the latter. This substance P-immunoreactive material disappeared after administration of capsaicin. Electron microscopic studies in prevertebral ganglia show that substance P-immunoreactive varicosities establish axodendritic contacts with the sympathetic neurons. These observations provide strong evidence for direct synaptic sensory-autonomic interactions in the prevertebral ganglia involving substance P-containing collaterals of peripheral sensory nerve fibres.
 ...
PMID:Localization of substance P in neuronal pathways. 618 80

At the light microscope level, the minute concentrations of substance P (SP) in rat spinal ventral horn can be visualized best by amplification with the double bridge PAP method of Vacca et al. (1975; 1980) in 5 microns paraffin tissue sections. Morphologically, the immunoreactive sites resemble punctate bodies. They occur in close apposition with the large ventral horn cells and their associated neuronal processes. By the Sternberger PAP procedure, we now describe these punctate bodies at the electron microscope level. Ultrastructurally, they appear as tiny boutons (terminal and preterminal) and small unmyelinated processes. The boutons and processes typically contain one to several immunolabeled dense core vesicles among many immunolabeled clear vesicles. They range in size near the limit of resolution of the light microscope (LM), thereby justifying further the use of LM amplification staining by the double bridge method. The immunolabeled boutons often synapse with large smooth dendrites (which may originate from motoneurons) by asymmetrical or symmetrical synaptic densities. Their synaptic densities appear immunostained as well. The data support the view that the electrophysiological action of SP in the ventral horn occurs in part by synaptic action along the processes of the ventral horn cells. Other mechanisms of action are considered for the peptide as well. Additional types of membrane specializations (synaptoid junctions) and SP neural circuits are described below.
 ...
PMID:Ultrastructural localization of substance P immunoreactivity in the ventral horn of the rat spinal cord. 618 47

The ultrastructural localization of substance P-like immunoreactivity (SPLI) in lamina I (marginal zone) and lamina IIO (outer substantia gelatinosa) of the dorsal horn of the macaque monkey was examined by the indirect antibody peroxidase-antiperoxidase method. SPLI was found in small unmyelinated and finely myelinated axons and a variety of terminal types. The majority of SPLI terminals contained a few to many large granular vesicles (mean diameter 90 nm) in addition to a population of small clear round vesicles. A very few terminals contained mainly small round vesicles. SPLI terminals were presynaptic in axosomatic, axodendritic and axospinous contacts forming, in all but the axosomatic junctions, asymmetrical synapses. Some axosomatic junctions were symmetrical. SPLI terminals also formed the center of glomeruli with unlabeled dendrites and dendritic spines; some of the unlabeled dendrites contained a few small scattered vesicles and large dense-core vesicles. In more complex formations 2 to 4 SPLI terminals were associated with one another and linked by desmosomal contacts. The individual terminals in the complexes or 'congregate terminals' were simple large granular vesicle containing terminals (LGV), LGV-central terminals of associated glomeruli, or terminals containing mainly small round vesicles. In the apical region of lamina I an unlabeled terminal was found occasionally in contact with an SPLI terminal, which in turn synapsed onto a dendrite. These contacts have some synaptic characteristics and the SPLI terminal was possibly postsynaptic. Most of the types of SPLI terminals resemble closely terminal types shown to be of primary afferent origin. These terminals which make direct contact with dorsal horn dendrites may be the morphological substrate for postsynaptic excitation of dorsal horn neurons by substance P. The contacts of unlabeled terminals with SPLI terminals may represent a morphological substrate by which other neurochemical substances such as enkephalin or serotonin may modulate the substance P effects on dorsal horn neuronal activity.
 ...
PMID:Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. I. Substance P immunoreactivity. 619 42

Distribution of substance P (SP)-positive fibers in the medial preoptic area (POM) of the rat and their origins were examined using indirect immunofluorescence. A very high density of SP-positive fibers was seen in the POM throughout its entire rostro-caudal extent. However, the distribution of these fibers was not even; the highest density was detected in the medial part of the POM, with less dense but still numerous fibers in the lateral part. On the other hand, in this area a small number of SP-positive cells could be found; a few cells were scattered in the rostral part and, in the caudal part, several cells could be seen in the ventral part of the POM. The origins of SP-positive fibers in the POM were experimentally examined. Since the destruction of the ventro-lateral part of the anterior hypothalamus (vlAH), where numerous SP-positive cells were seen, resulted in a marked decrease of SP-positive fibers in the POM on the operated side, the majority of these fibers may originate from SP-positive cells in the vlAH. The fine structure of SP-positive terminals in the POM were investigated by electron-microscopic immunohistochemical techniques. Immunoreactive terminals contained a few large granular vesicles together with numerous small vesicles, and they made synaptic contacts mainly with dendrites which were devoid of immunoreactive materials. Two different synaptic contacts could be distinguished: one asymmetrical (Gray's type I) and the other symmetrical (Gray's type II), with the latter being predominant.
 ...
PMID:Experimental immunohistochemical studies on the distribution and origins of substance P in the medial preoptic area of the rat. 620 80

Enkephalinergic axons and terminals were identified by the PAP immunohistochemical method in lamina I (marginal zone) and lamina IIO (outer substantia gelatinosa) in the dorsal horn of the monkey spinal cord. Synaptic profiles with enkephalin-like immunoreactivity (MELI) contained clear, round, vesicles, sometimes a few large granular vesicles, and usually formed asymmetrical contacts. MELI terminals forming synaptic contacts with various sizes of dendrites and with dendritic spines were the most common type of relationship found; axosomatic contacts were few. Additionally, two types of complexes were observed in which an MELI terminal formed a specialized apposition with an unlabelled terminal. The contact often resembled a synapse and in most cases the MELI terminal was suspected to be presynaptic. One complex consisted of a MELI terminal apposing the LGV type terminal (containing large granular vesicles), which in turn was presynaptic to a dendrite. (The identity of the LGV terminal could not be determined, but it had some characteristics similar to those described for substance P terminals and for a class of primary afferents in the monkey dorsal horn). The other type of complex consisted of a MELI terminal apposing an R-type terminal (containing small, round, clear vesicles) which was in turn presynaptic to a dendrite. Often, the MELI terminal also formed a synapse onto the same dendrite. The axodendritic, axospinous and axosomatic contacts of MELI terminals in the superficial dorsal horn may produce some of the depressive postsynaptic-like effects of enkephalin iontophoresis onto dorsal horn neurons. In these cases the responses of dorsal horn neurons to both low threshold and nociceptive primary afferents is suppressed. However, the opiate receptor-dependent PAD of C-fibers observed in the dorsal horn may be mediated by the MELI complexes formed with LGV and R terminals found in lamina I.
 ...
PMID:Ultrastructure of chemically defined neuron systems in the dorsal horn of the monkey. II. Methionine-enkephalin immunoreactivity. 635 63

The synaptic organization of nerve terminals containing calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), substance P (SP) and enkephalin (ENK) in the intralaryngeal local ganglia of the cat was investigated by immunoelectron microscopy. CGRP-immunoreactive (IR) and VIP-IR varicose fibers formed mainly axo-dendritic synapses, whereas SP-IR and ENK-IR varicose fibers made axo-somatic synapses to the principal neurons of the local ganglion. The synaptic specializations of the CGRP-IR varicosities were asymmetrical, or Gray's type I, whereas the other peptide-IR varicosities showed symmetrical, or Gray's type II, synaptic specializations. After denervation of the extrinsic nerves, CGRP-IR varicose fibers disappeared from the ganglion, but VIP-IR, SP-IR and ENK-IR varicose fibers and synapses remained. These results suggest that local ganglia act as an integration center of laryngeal function rather than as a unidirectional parasympathetic relay center.
 ...
PMID:Immunoelectron microscopic studies of synaptic organization in the intralaryngeal ganglia of the cat. 750 65


<< Previous 1 2 3 4 Next >>