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)

Growth and distribution of noradrenaline (NA) fibres from the implant into the thalamus of host rats were examined at 5-13 months after the implantation by immunohistochemistry using NA or tyrosine hydroxylase antisera. Cell suspension dissociated from the locus coeruleus (LC) region of 14-day-old rat fetuses was implanted into the center of the unilateral thalamus in adult rats from which the noradrenergic afferents to the thalamus had been eliminated with 6-hydroxydopamine treatment. A dense network of varicose NA-immunoreactive (NA-IR) fibres extended laterally into the posterior thalamic nuclear group and the ventral posterolateral thalamic nucleus from the implant in a pattern similar to that the intrinsic noradrenergic fibres form in the normal thalamus, i.e. laterally rich and medially poor NA fibres. Electron microscopic observations revealed that varicosities of NA-IR fibres formed symmetrical as well as asymmetrical axodendritic synapses and axo-axonic synapses with the host neurons as seen in the normal thalamus. labelled dendrite-like fibres of graft origin penetrated deep into the host brain and received afferents from non-labelled axon terminals. Varicosities of NA-IR fibres in the LC implanted animal formed axo-dendritic synapses at the higher ratio than those in the normal animal did. These results show that implanted fetal noradrenergic neurons innervate target regions of the thalamus specifically as the noradrenergic fibres in the normal thalamus do and maintain the innervation for a long time in the noradrenergically denervated rats.
 ...
PMID:Specific innervation of the rat thalamus by grafted noradrenergic locus coeruleus neurons. 896 74

In order to examine the morphological substrates for neuronal connections between neuronal elements of the coeliac-mesenteric ganglion containing immunoreactivity (IR) for tyrosine hydroxylase (TH) and substance P (SP), a double-immunostaining was performed. The first antigen to SP was labelled with gold-substituted silver-intensified peroxidase, which results in a granular gold deposit of high electron and light opacity. The second antigen was the TH labelled with peroxidase and a diaminobenzidine chromogen without silver-gold particles. About of 85% of the neurons contained TH immunoreactivity in the coeliac-mesenteric ganglia. The SP IR nerve fibres were mostly found around the principal ganglion cells throughout the ganglion. In most cases they made direct synaptic contact with TH positive nerve cells and dendrites. These SP-IR boutons were also found in synaptic contact with other non-labelled postsynaptic terminals and with the soma. SP-IR nerve terminals establish both symmetrical and asymmetrical synaptic contacts with TH-IR nerve elements. Some of the nerve cells which ware TH positive, were also labelled for SP. TH positive boutons were also observed in synaptic contact with other TH-IR perikarya and dendrites. Our results suggest that SP may play an important role for the integrative activities of the ganglion with regard to gastrointestinal functions.
 ...
PMID:Electron microscopic immunocytochemical evidence for the synaptic connections between tyrosine hydroxylase and substance P containing nerve elements in the coeliac ganglion of cat revealed by a double labelling technique. 912 85

Synaptic contacts between noradrenaline (NA) neurons and GABA (gamma-aminobutyric acid) afferents and/or substance P (SP) afferents in the locus coeruleus (LC) were examined by a combination of immunoelectron microscopic mirror method and double-immunostaining method. For visualization of NA and GABA, we used antibodies against NA and GABA synthesizing enzymes, i.e., tyrosine hydroxylase (TH) and glutamic acid decarboxylase (GAD). GAD-immunoreactive (IR) and SP-IR axon terminals often made synaptic contacts with NA neurons, respectively. Furthermore, we identified that a single NA neuron simultaneously receives synaptic inputs from GAD-IR and SP-IR afferents. These NA neurons made symmetrical synaptic contacts with GAD-IR axon terminals and asymmetrical contacts with SP-IR axon terminals. This suggests that central NA neuronal mechanisms are affected by GABA and SP neurons in a different manner.
 ...
PMID:GABA-ergic and substance P-ergic double-innervation to noradrenergic neurons in the rat locus coeruleus. 930 37

The topographical distribution of catecholaminergic nerve fibres and their anatomical relationship to cholinergic elements in the rat globus pallidus were studied. Peroxidase-antiperoxidase and two-colour immunoperoxidase staining procedures were used to demonstrate tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT) and choline acetyltransferase (ChAT) immunoreactivities, combined with acetylcholinesterase (AChE) pharmacohistochemistry. TH immunoreactive nerve fibres were seen to enter the globus pallidus from the medial forebrain bundle. The greatest density of such fibres was found in the ventral region of the globus pallidus, which was also characterized by the greatest density of ChAT immunoreactive neurons. TH immunoreactive nerve fibres showed varicose arborizations and sparse boutons, which were occasionally seen in close opposition to cholinergic structures. In all regions of the globus pallidus, there were also larger, smooth TH immunoreactive nerve fibres of passage to the caudate putamen. A smaller number of DBH immunoreactive nerve fibres and terminal arborizations were found in the substantia innominata, internal capsule and in the globus pallidus bordering these structures. A few PNMT immunoreactive nerve fibres in the substantia innominata and internal capsule did not enter the globus pallidus. Electron microscopy revealed TH immunoreactive synaptic profiles in the ventromedial area of the globus pallidus corresponding to the nucleus basalis magnocellularis of Meynert (nBM). These made mainly symmetrical and only a few asymmetrical synaptic contacts with dendrites containing AChE reaction product. The results indicate that cholinergic structures in the nBM are innervated by dopaminergic fibres and terminals, with only a very small input from noradrenergic fibres.
 ...
PMID:Distribution of catecholaminergic afferent fibres in the rat globus pallidus and their relations with cholinergic neurons. 971 Jan 45

Immunocytochemical identification of dopaminergic neurons was performed using an immunoperoxidase method employing antibodies to tyrosine hydroxylase. The ultrastructure of synaptic contacts on dopaminergic (tyrosine hydroxylase immunopositive (TP) cells) neurons was investigated in the substantia nigra in the brains of four patients with schizophrenia and three mentally healthy subjects (controls). The substantia nigra of schizophrenia patients differed from control material in showing the following changes in the ultrastructure of presynaptic terminals contacting TP neurons: reductions in the size of terminals with dense matrix and poorly distinguished vesicles; swelling of terminals with small numbers of vesicles displaced from the active zone of the synapse; hyperplasia of mitochondria in some presynaptic boutons; appearance of membranous lamellar structures within or adjacent to presynaptic boutons. These changes to terminals were located mostly on the distal (small and intermediate) TP dendrites in the compact zone of the substantia nigra, where nearly all the dendrites detected belonged to dopaminergic neurons and the altered terminals formed asymmetrical contacts with short active zones. In the reticular part of the substantia nigra of schizophrenic patients, changes in the ultrastructure of presynaptic terminals were relatively rare; altered terminals contacted both tyrosine hydroxylase immunopositive as well as with the tyrosine hydroxylase immunonegative dendrites located in this structure.
 ...
PMID:Synaptic contacts in schizophrenia: studies using immunocytochemical identification of dopaminergic neurons. 1043 12

Hypocretin has been identified as a regulator of metabolic and endocrine systems. Several brain regions involved in the central regulation of autonomic and endocrine processes or attention are targets of extensive hypocretin projections. The most dense arborization of hypocretin axons in the brainstem was detected in the locus coeruleus (LC). Multiple labeling immunocytochemistry revealed a massive synaptic innervation of catecholaminergic LC cells by hypocretin axon terminals in rats and monkeys. In both species, all tyrosine hydroxylase-immunopositive cells in the LC examined by electron microscopy were found to receive asymmetrical (excitatory) synaptic contacts from multiple axons containing hypocretin. In parallel electrophysiological studies with slices of rat brain, all LC cells showed excitatory responses to the hypocretin-2 peptide. Hypocretin-2 uniformly increased the frequency of action potentials in these cells, even in the presence of tetrodotoxin, indicating that receptors responding to hypocretin were expressed in LC neurons. Two mechanisms for the increased firing rate appeared to be a reduction in the slow component of the afterhyperpolarization (AHP) and a modest depolarization. Catecholamine systems in other parts of the brain, including those found in the medulla, zona incerta, substantia nigra or olfactory bulb, received significantly less hypocretin input. Comparative analysis of lateral hypothalamic input to the LC revealed that hypocretin-containing axon terminals were substantially more abundant than those containing melanin-concentrating hormone. The present results provide evidence for direct action of hypothalamic hypocretin cells on the LC noradrenergic system in rats and monkeys. Our observations suggest a signaling pathway via which signals acting on the lateral hypothalamus may influence the activity of the LC and thereby a variety of CNSfunctions related to noradrenergic innervation, including vigilance, attention, learning, and memory. Thus, the hypocretin innervation of the LC may serve to focus cognitive processes to compliment hypocretin-mediated activation of autonomic centers already described.
 ...
PMID:Hypocretin (orexin) activation and synaptic innervation of the locus coeruleus noradrenergic system. 1054 56

Synapses of intraglomerular processes of tyrosine hydroxylase-immunoreactive neurons in the rat main olfactory bulb were examined by electron microscopic immunocytochemistry. Prominent characteristics of intraglomerular synapses of tyrosine hydroxylase-immunoreactive elements were that the vast majority (about 80%) of their synaptic inputs were asymmetrical synapses from olfactory nerve terminals and, though far smaller in proportion, one half of the remaining were asymmetrical synapses from mitral/tufted cell dendrites and the other half were symmetrical synapses from gamma-aminobutyric acid-like immunoreactive elements. So far, we have observed no typical reciprocal synapses between tyrosine hydroxylase-immunoreactive processes and mitral/tufted dendrites; however, we have often identified serial synapses; that is, asymmetrical synapses from olfactory nerve terminals or mitral/tufted cell dendrites to tyrosine hydroxylase-immunoreactive processes, and then symmetrical synapses from the latter to different mitral/tufted cell dendrites. These synaptic connections of tyrosine hydroxylase-immunoreactive neurons were very different from those of Calbindin-D(28k)-immunoreactive neurons, which received no synaptic contact directly from olfactory nerve terminals but formed reciprocal synapses with mitral/tufted cells as we analysed previously.Thus, our present and previous electron microscopic studies combined with confocal laser scanning light microscopy clearly indicated for the first time the heterogeneity of periglomerular neurons, not only in their chemical and morphological features, but also in their synaptic organization in the olfactory glomerulus.
 ...
PMID:Chemically defined neuron groups and their subpopulations in the glomerular layer of the rat main olfactory bulb--IV. Intraglomerular synapses of tyrosine hydroxylase-immunoreactive neurons. 1106 32

Delta enkephalin analogue [D-Ala(2),D-Leu(5)]enkephalin (DADLE) has been shown to protect dopamine transporters from methamphetamine-induced neurotoxicity. In the present study, we demonstrate that exposure of embryonic ventral mesencephalic cells to DADLE (0.01 g/ml), prior to intrastriatal transplantation, enhanced functional recovery and graft survival in 6-hydroxydopamine-induced hemiparkinsonian rats. At 6 and 8 weeks posttransplantation, animals that received DADLE-treated cell grafts exhibited significantly higher (near normal) spontaneous locomotor behaviors, as well as trends of greater reversal of motor asymmetrical behaviors compared with animals that received nontreated cell grafts. Histological examination revealed that animals transplanted with DADLE-treated cell grafts exhibited about twice the number of surviving tyrosine hydroxylase-immunoreactive grafted neurons compared with those animals that received nontreated cell grafts. These results suggest that DADLE should be considered as an adjunctive agent for neural transplantation therapy in Parkinson's disease.
 ...
PMID:Delta opioid peptide augments functional effects and intrastriatal graft survival of rat fetal ventral mesencephalic cells. 1129 72

Exogenous application of transforming growth factors-beta (TGF beta) family proteins, including glial cell line-derived neurotrophic factor (GDNF), neurturin, activin, and bone morphogenetic proteins, has been shown to protect neurons in many models of neurological disorders. Finding a tissue source containing a variety of these proteins may promote optimal beneficial effects for treatment of neurodegenerative diseases. Because fetal kidneys express many TGF beta trophic factors, we transplanted these tissues directly into the substantia nigra after a unilateral 6-hydroxydopamine lesion. We found that animals that received fetal kidney tissue grafts exhibited (1) significantly reduced hemiparkinsonian asymmetrical behaviors, (2) a near normal tyrosine hydroxylase immunoreactivity in the lesioned nigra and striatum, (3) a preservation of K(+)-induced dopamine release in the lesioned striatum, and (4) high levels of GDNF protein within the grafts. In contrast, lesioned animals that received grafts of adult kidney tissues displayed significant behavioral deficits, dopaminergic depletion, reduced K(+)-mediated striatal dopamine release, and low levels of GDNF protein within the grafts. The present study suggests that fetal kidney tissue grafts can protect the nigrostriatal dopaminergic system against a neurotoxin-induced parkinsonism, possibly through the synergistic release of GDNF and several other neurotrophic factors.
 ...
PMID:Involvement of GDNF in neuronal protection against 6-OHDA-induced parkinsonism following intracerebral transplantation of fetal kidney tissues in adult rats. 1149 28

The genetically hypothyroid mouse, Tshr(hyt), has a single point mutation resulting in a defective thyroid-stimulating hormone receptor, and therefore a non-functional thyroid gland. This is an autosomal recessive disorder and affected mice have been reported to have a number of somatic and behavioral deficits. This study reports a pronounced, spontaneous, asymmetrical circling behavior in the Tshr(hyt) mouse. The spontaneous circling behavior appeared in about 25% of the homozygous animals, in both males and females. The circling usually appeared by postnatal day 35 and continued throughout the lifespan of the animal. The circling was in one direction only, either clockwise or counterclockwise, with the directional preference being almost absolute. A stereological analysis of tyrosine hydroxylase immunoreactive neurons in the substantia nigra and adjacent ventral tegmental area of circling homozygous mice, non-circling homozygous mice and heterozygous mice revealed that the circlers had significantly fewer (40% reduction) midbrain dopamine neurons than those animals that did not circle. There was not an association between the direction of the circling and an asymmetry in the number of dopamine neurons in the midbrains of these mice. There was no difference in the number of dopamine neurons in the midbrain of the homozygous non-circlers and the heterozygous mice. These studies indicate that about 25% of genetically hypothyroid mice demonstrated a spontaneous, perseverative, unilateral circling behavior that was associated with a significant reduction in the number of their midbrain dopamine neurons. Thus congenitally hypothyroid mice are at risk for a reduction in the number of nigral dopamine neurons and an associated repetitive movement disorder.
 ...
PMID:Spontaneous circling behavior and dopamine neuron loss in a genetically hypothyroid mouse. 1153 Feb 27


<< Previous 1 2 3 4 5 Next >>