Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.14.16.2 (tyrosine hydroxylase)
 14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The substantia nigra (SN) is a midbrain center composed of dopaminergic (DA-) and gamma aminobutyric acid (GABA)ergic (GABA-) neurons. In this study, we investigated the topographical relationship between both cell populations and their chemical profile by using single and double immunostaining for tyrosine hydroxylase (TH), glutamic acid decarboxylase (GAD), cholecystokinin (CCK), calretinin (CR), calbindin (CB), parvalbumin (PV), and nitric oxide synthase (NOS). Our results showed that DA-cells are arranged in two bands, one rostrodorsal that corresponds to the SN pars compacta (SNC), and another caudoventral that corresponds to the SN pars reticulata (SNR) and emits cell bridges that make contact with the rostrodorsal one. In the SNR, GABA-cells are arranged in dorsoventrally elongated clusters that occupy DA-cell free regions. According to cytoarchitectural, topographical, and chemical criteria, we identified ten different cell groups: five dopaminergic ones, and five GABAergic ones. Within DA-cells, we found a cell group in the dorsomedial portion of the SNC which contains CCK, CR, and CB (dmSNC); DA-cells in the SN pars lateralis (SNL) which also contain CCK, CR and CB; DA-cells in the rostral half of the SNC containing CCK and CR (rSNC); DA-cells in the SNR and the caudal half of the SNC which only express CR (cSNC-SNR), and a DA-cell group in the lateral part of the SNC that contains none of the markers studied (lSNC). Within GABA-cells, we distinguished: large GABA-cells in the SNL that contain PV; large GABA-cells in the rostrolateral part of the SNR containing PV and NOS (rlSNR), small GABA-cells in the caudomedial part of the SNR containing PV (cmSNR), and two groups of small GABA-cells in the rostromedial portion of the SNR, one of them containing CR (rmcSNR), and the other containing NOS (rmnSNR). These data suggest that over a compartmental and complementary organization, DA- and GABA-nigral cells form a mosaic of neurochemically different subnuclei which probably differ in their physiological and pharmacological properties and vulnerability to aggression.
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PMID:Compartmental organization and chemical profile of dopaminergic and GABAergic neurons in the substantia nigra of the rat. 1081 75

Relative preservation of dopaminergic axons in patches and a subcallosal layer was observed in the dorsal, lateral and caudal striatum 4 weeks after intrastriatal injection of 6-hydroxydopamine (6-OHDA), a neurotoxin selective for catecholaminergic neurons. Since calcium binding proteins are reported to provide neuroprotective influence in neurons, differences in the distribution of the calcium binding proteins might be related to the different vulnerabilities of dopaminergic neurons and axons to neurotoxins. To address this possibility, we characterized patches of relatively dense tyrosine hydroxylase-immunoreactive (TH-IR) axons in intrastriatal 6-OHDA lesioned rats, focusing on two calcium binding proteins, calbindin (CB) and calretinin (CR). The patches and subcallosal layer of preserved dopaminergic axons in the striatum of rats lesioned with 6-OHDA contained CR, a 31-kDa calcium-binding protein, but interestingly not CB. Dopaminergic neurons containing CR in the substantia nigra pars compacta (SNpc) were relatively spared compared to those that did not contain CR. Taken together, our data indicate that dopaminergic axons and neurons containing CR in the nigrostriatal pathway are more resistant to 6-OHDA lesion than those that do not contain CR.
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PMID:Calretinin-containing axons and neurons are resistant to an intrastriatal 6-hydroxydopamine lesion. 1082 80

It is well established that the supramammillary nucleus plays a critical role in hippocampal theta rhythm generation/regulation by its direct and indirect (via the septal complex) connections to the hippocampus. Previous morphological and electrophysiological studies indicate that both the supramammillo-hippocampal and supramammillo-septal efferents contain excitatory transmitter. To test the validity of this assumption, transmitter specific retrograde tracer experiments were performed. [3H]D-aspartate was injected into different locations of the hippocampus (granular and supragranular layers of the dentate gyrus and CA2 and CA3a areas of the Ammon's horn) and septal complex (medial septum and the area between the medial and lateral septum) that are known targets of the supramammillary projection. Consecutive vibratome sections prepared from the entire length of the posterior hypothalamus, including the supramammillary area, were immunostained for calretinin, tyrosine hydroxylase, or calbindin, and further processed for autoradiography. Radiolabeled, radiolabeled plus calretinin-containing, and calretinin-immunoreactive neurons were plotted at six different oro-caudal levels of the supramammillary area. The results demonstrated that following both hippocampal and septal injection of the tracer, the majority of the retrogradely radiolabeled (glutamatergic/aspartatergic) cells are immunoreactive for calretinin. However, non-radiolabeled calretinin-containing neurons and radiolabeled calretinin-immunonegative cells were also seen, albeit at a much lower density. These observations clearly indicate the presence of glutamatergic/aspartatergic projections to both the hippocampus and septal complex. It may be assumed that this transmitter could play a role in hippocampal theta rhythm generation/regulation.
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PMID:The supramammillo-hippocampal and supramammillo-septal glutamatergic/aspartatergic projections in the rat: a combined [3H]D-aspartate autoradiographic and immunohistochemical study. 1084 10

Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for mesencephalic dopaminergic neurons. Subpopulations of these neurons express the calcium-binding proteins calbindin (CB) and calretinin (CR). Understanding the specific effects of GDNF on these neurons is important for the development of an optimal cell replacement therapy for Parkinson's disease. To investigate the effects of GDNF on the morphological complexity of mesencephalic tyrosine hydroxylase (TH)-immunoreactive (-ir), CB-ir, and CR-ir neurons, dissociated cultures of embryonic (E14) rat ventral mesencephalon were prepared. Chronic administration of GDNF (10 ng/ml) for 7 days promoted the survival of TH-ir and CB-ir neurons but did not alter the density of CR-ir neurons. Total fiber length/neuron and number of branching points/neuron of CB-ir and CR-ir cells were significantly increased after GDNF treatment (2x for CB-ir cells and 1.4x and 1.7x, respectively, for CR-ir cells), which resulted in a significantly larger size of neurite field/neuron (2.9x and 1.5x for CB-ir and CR-ir neurons, respectively). The number of primary neurites/neuron of CB-ir neurons was found to be 1.5x larger, while no difference could be detected for CR-ir cells. Assessment of the effects of GDNF on TH-ir neurons unveiled a similar outcome with an increased total fiber length/neuron (1.5x), an increased number of primary neurites/neuron (1.6x), and a twofold larger size of neurite field/neuron. In conclusion, our findings recognize GDNF as a neurotrophic factor that stimulates the morphological differentiation of ventral mesencephalic CB-ir and CR-ir neurons.
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PMID:Glial cell line-derived neurotrophic factor stimulates the morphological differentiation of cultured ventral mesencephalic calbindin- and calretinin-expressing neurons. 1087 17

Solid-pseudopapillary tumor of the pancreas (SPT) has distinctive morphologic and biologic features but an unclear origin. It is classified among the pancreatic epithelial tumors, though many are reported to be negative for cytokeratin. Also unclear are its neuroendocrine differentiation, its capability to express alpha-1-antitrypsin (AAT) and, in view of the tumor's striking prevalence in women, its relationship with the female genital tract. To clarify these issues, the immunoprofiles of 59 SPTs were defined by applying a battery of antibodies against cytokeratin, vimentin, neuron-specific enolase (NSE), synaptophysin, chromogranin A, tyrosine hydroxylase (TH), AAT, LeuM1, Ki-M1P, smooth-muscle actin, CD34, alpha-inhibin, calretinin, placental alkaline phosphatase (PLAP), and progesterone and estrogen receptors. The most consistent markers with the strongest immunoreactivity were vimentin, AAT, NSE, and the progesterone receptor, which were each found in more than 90% of the tumors. Using immunocytochemical methods involving antigen retrieval, cytokeratin was demonstrated in almost 70% of the cases. Synaptophysin was found in 22% of the tumors, while chromogranin was absent and tyrosine hydroxylase was only present in a few tumors. None of the other markers tested were expressed by SPTs. This staining pattern fails to reveal a clear phenotypic relationship with any of the defined cell lineages of the pancreas. In view of the striking female preponderance of SPTs and the known close approximation of the genital ridges to the pancreatic anlage during embryogenesis, it is, however, hypothesized that SPTs might derive from genital ridge/ovarian anlage-related cells, which were attached to the pancreatic tissue during early embryogenesis.
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PMID:Solid-pseudopapillary tumor of the pancreas: its origin revisited. 1088 41

Our previous work (Couper Leo et al. [2000] J. Comp. Neurol. 417:325-336) introduced a technique for focally denervating the olfactory bulb soon after birth and described the pattern of changes incurred by this procedure by postnatal day (P) 30. The current study extends these findings with a developmental analysis of the effects of focal denervation in P10 and P20 rats. The results suggest that denervation begins to affect bulb architecture and cell survival soon after the procedure is performed, but that alterations within the bulb occur over an extended time period. For example, at P10, bulb and laminar sizes and mitral/tufted cell profile number had begun their decline, and nearly all measurements were significantly reduced by P20. Furthermore, a superficial-to-deep gradient of alterations in bulb architecture and a temporal separation of the effects on mitral/tufted cell dendrites vs. somata were observed. Immunohistochemical analyses of olfactory marker protein (OMP)-, calretinin- calbindin-, parvalbumin-, tyrosine hydroxylase-, and glutamic acid decarboxylase-stained sections indicated that: 1) denervation alters the interaction between olfactory axons and their targets in a developmentally significant manner; 2) the fine structure of denervated cells is altered; 3) cell phenotypes are differentially affected by loss of afferent contact, perhaps due to the age-dependent expression of their defining antigens; and 4) specific cell populations may be lost as a result of denervation.
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PMID:Focal denervation alters cellular phenotypes and survival in the rat olfactory bulb: a developmental analysis. 1097 41

The cyto- and chemoarchitecture of basal forebrain cholinergic neurons (BFCN) was investigated in the lower primate, the common marmoset (Callithrix jacchus). A large population of magnocellular, hyperchromic, and choline acetyltransferase (ChAT)-positive neurons was detected in the marmoset basal forebrain. The distribution of these neurons was similar to those in higher primates. Thus, ChAT-positive neurons were observed in the medial septum (Ch2), the vertical (Ch2) and horizontal (Ch3) limbs of the diagonal band of Broca, and the nucleus basalis of Meynert (Ch4). The Ch4 complex was relatively well differentiated and displayed distinct sectors. We detected anterior (Ch4a, with a medial and a lateral subdivision), intermediate (Ch4i, with a dorsal and a ventral subdivision), and posterior (Ch4p) sectors in the marmoset Ch4. The Ch4i was relatively small while the Ch4p was large. Similar to the rodent, the marmoset Ch1 extended quite a distance posteriorly, and the Ch4p displayed a major interstitial component distributed within the globus pallidus, its medullary laminae, and the internal capsule. Virtually all of the marmoset BFCN displayed acetylcholinesterase activity, and low affinity (p75(NTR)) and high affinity (Trk) neurotrophin receptor immunoreactivity. A majority contained immunoreactivity for calbindin-D(28K) and calretinin. Many of the Ch4 neurons also displayed tyrosine hydroxylase immunoreactivity. The BFCN lacked galanin immunoreactivity, but were innervated by galanin-positive fibers. None of the marmoset BFCN were NADPH-d-positive. Thus, the BFCN display major anatomical and biochemical differences in the marmoset when compared with higher primates. The marmoset BFCN also display many characteristics common to other primates. This fact, combined with the relatively short life span of the marmoset, indicates that this species may be ideal for studies of age-related changes in the BFCN.
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PMID:Cyto- and chemoarchitecture of basal forebrain cholinergic neurons in the common marmoset (Callithrix jacchus). 1099 91

The rat major pelvic ganglion contains the majority of sympathetic and parasympathetic postganglionic neurons that innervate the pelvic viscera. Previous studies have indicated that it is only the sympathetic population of this ganglion that is susceptible to age-associated changes. We have examined the distribution of the neuronal calcium binding proteins calbindin-D28k, calretinin and parvalbumin by immunohistochemistry in young adult and aged rats and have discovered that calbindin-D28k is only present in the sympathetic neurons (identified by tyrosine hydroxylase immunostaining) and not in parasympathetic neurons (identified by VIP immunostaining). In the aged rats the number of calbindin-immunoreactive sympathetic neurons of the major pelvic ganglion was dramatically reduced. Calretinin and parvalbumin-immunoreactivity was present at a lower level of fluorescence than that of calbindin immunoreactivity in all the neurons of the major pelvic ganglion and this level was unchanged in aged rats. Thus we suggest that the decline of intracellular calbindin D28k levels may lead to impaired calcium buffering capacity which might be a contributory factor in the age-associated attrition of pelvic sympathetic neurons.
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PMID:Decreased calbindin-D28k immunoreactivity in aged rat sympathetic pelvic ganglionic neurons. 1099 56

The histochemistry of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and immunoreactivity of neuronal nitric oxide synthase (nNOS-IR) can be demonstrated in various cell types of the vertebrate retina. In this study, we have focused on characterizing the different NADPH-d-positive amacrine cell types in turtle retina. Cryostat sections were examined by confocal laser scanning microscopy for double immunofluorescence with antibodies against nNOS and either GABA or glycine, or by combining histochemistry with immunocytochemistry to obtain triple labeling with NADPH-d, GABA, and glycine. Forty-eight percent of the NADPH-d-labeled amacrine cells colocalized GABA, 52% glycine. Here we show that two morphologically different types of amacrine cell are nNOS/glycine-IR and three types are nNOS/GABA-IR. Antibodies against calretinin, parvalbumin, somatostatin, tyrosine hydroxylase, and choline acetyltransferase did not colocalize with nNOS-IR or NADPH-d-labeled amacrine cells, but 15% of the NOS-labeled amacrine cells showed immunoreactivity against calbindin. Only GABA has been seen to colocalize with NADPH-d in amacrine cells in previous reports in other species. The finding here of glycine colocalizing with NO-containing cells is novel. We suggest that NO, apart from its well known function in gap junction regulation, can also modulate the release of both GABA and glycine in the turtle retina.
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PMID:Morphological and neurochemical diversity of neuronal nitric oxide synthase-positive amacrine cells in the turtle retina. 1107 11

In a previous work, mapping early tyrosine hydroxylase (TH) expressing primordia in human embryos, the tegmental origin of the substantia nigra (SN) and ventral tegmental area (VTA) was located across several neuromeric domains: prosomeres 1-3, midbrain, and isthmus (Puelles and Verney, [1998] J. Comp. Neurol. 394:283-308). The present study examines in detail the architecture of the neural wall along this tegmental continuum in 6-7 week human embryos, to better define the development of the SN and VTA. TH-immunoreactive (TH-IR) structures were mapped relative to longitudinal subdivisions (floor plate, basal plate, alar plate), as well as to radially superposed strata of the neural wall (periventricular, intermediate, and superficial strata). These morphologic entities were delineated at each relevant segmental level by using Nissl-stained sections and immunocytochemical mapping of calbindin, calretinin, and GABA in adjacent sagittal or frontal sections. A numerous and varied neuronal population originates in the floor plate area, and some of its derivatives become related through lateral tangential migration with other neuronal populations born in distinct medial and lateral portions of the basal plate and in a transition zone at the border with the alar plate. Some structural differences characterize each segmental domain within this common schema. The TH-IR neuroblasts arise predominantly within the ventricular zone of the floor plate and, more sparsely, within the adjacent medial part of the basal plate. They first migrate radially from the ventricular zone to the pia and then apparently move laterally and slightly rostralward, crossing the superficial stratum of the basal plate. Several GABA-IR cell populations are present in this region. One of them, which might represent the anlage of the SN pars reticulata, is generated in the lateral part of the basal plate.
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PMID:Structure of longitudinal brain zones that provide the origin for the substantia nigra and ventral tegmental area in human embryos, as revealed by cytoarchitecture and tyrosine hydroxylase, calretinin, calbindin, and GABA immunoreactions. 1108 87


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