Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.14.16.2 (tyrosine hydroxylase)
14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper re-examines a previously published segmental map of the frog diencephalon (Puelles et al. [1996] Brain Behav.Evol. 47:279-310) by means of immunocytochemical mapping of calretinin, calbindin, and tyrosine hydroxylase. The distribution of neuronal populations, axon tracts, and neuropils immunoreactive for these markers was studied in adult specimens of Rana perezi and Xenopus laevis sectioned sagittally or horizontally. Emphasis was placed on study of the relationship of observed chemoarchitectural boundaries with the postulated overall prosomeric organization and the schema of nuclear subdivisions we reported previously, based on acetylcholinesterase histochemistry and Nissl pattern in Rana. The data reveal a large-scale correspondence with the segmental map in both species, although some differences were noted between Rana and Xenopus. Notably, retinorecipient neuropils were generally immunoreactive for calretinin only in Rana. Importantly, calretinin immunostaining underlines particularly well the transverse prosomeric boundaries of the dorsal thalamus. A number of nuclear subdivisions noted before with AChE were corroborated, and some novel subdivisions became apparent, particularly in the anterior nucleus of the dorsal thalamus and in the habenular complex. The mapping of tyrosine hydroxylase clarified the segmental distribution of the catecholaminergic cell groups in the frog forebrain, which is comparable to that observed in other vertebrates.
...
PMID:Patterns of calretinin, calbindin, and tyrosine-hydroxylase expression are consistent with the prosomeric map of the frog diencephalon. 1071 42

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.
...
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.
...
PMID:Calretinin-containing axons and neurons are resistant to an intrastriatal 6-hydroxydopamine lesion. 1082 80

The present study used mice deficient for dopamine D(2) and D(3) receptors to test whether the expression of these two members of the D(2) class of receptors is essential for the normal expression of three markers that characterize the neurochemical differentiation of the striatum: the calcium-binding protein calbindin, tyrosine hydroxylase and acetylcholinesterase. Results from these experiments revealed that the expression of striatal tyrosine hydroxylase (the rate-limiting enzyme of dopamine synthesis) and acetylcholinesterase is unaffected even by the combined knockout of D(2) and D(3) receptors. However, D(2) and D(3) receptor knockouts differently affect the striatal expression of calbindin-D(28k) immunoreactivity. Prominent changes in the cellular distribution of calbindin are detected in striatal neurons of D(2) mutant mice. Whereas calbindin immunolabeling of wild-type neurons is prominent in the nuclei and the cytoplasm of medium spiny neurons, in D(2) mutant mice, calbindin immunoreactivity is concentrated exclusively in the cytoplasmic rim of these neurons. Such changes in the cellular distribution of calbindin expression are not detected in mice lacking D(3) receptors. In these mutants, however, a lesser density of calbindin-immunoreactive neuropil is detected in the ventral portions of the striatum, i.e. in regions in which D(3) receptors are thought to be expressed at highest levels. Mice lacking both D(2) and D(3) receptors show both phenotypes. The altered cellular distribution of calbindin in D(2) mutants is likely to have functional consequences for some of the Ca(2+)-mediated cellular functions. The topography of the decreased density of striatal calbindin immunorectivity in D(3) mutants suggests a role for D(3) receptors in supporting the expression of striatal calbindin. The observation that mice lacking both D(2) and D(3) receptors show a combination of the D(2) and D(3) mutant phenotypes indicates that each of the different phenotypes detected in the single mutants is indeed related to the lack of the two different D(2)-like receptor subtypes.
...
PMID:Targeted disruption of the dopamine D(2) and D(3) receptor genes leads to different alterations in the expression of striatal calbindin-D(28k). 1082 32

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.
...
PMID:The supramammillo-hippocampal and supramammillo-septal glutamatergic/aspartatergic projections in the rat: a combined [3H]D-aspartate autoradiographic and immunohistochemical study. 1084 10

Calbindin-D 28kD is a calcium binding protein reported to protect neurons from degeneration by buffering intracellular calcium. It is expressed in midbrain dopaminergic neurons reported to be relatively resistant to degeneration in Parkinson's disease and certain of its animal models. Lesions of the nigrostriatal pathway produced in rats following injection of 6-hydroxydopamine result in a neurochemical profile similar to that seen in patients with Parkinson's disease. In the present study, brains were processed to exhibit tyrosine hydroxylase- and calbindin-D 28kD immunoreactivities in sections through the ventral mesencephalon at 3, 7, 10, 14 and 21 days after 6-hydroxydopamine had been injected into the medial forebrain bundle. Numbers of ventral mesencephalic calbindin-D 28kD immunoreactive neurons were significantly reduced ipsilateral to the lesions at 3 days post-lesion and, following slight recovery, remained significantly depleted through post-lesion day 21. The densities of calbindin-D 28kD and tyrosine hydroxylase immunoreactive neurons were different only at the 3 day post-lesion time point, when the apparent loss of calbindin-D 28 kD immunoreactive profiles was significantly greater. A lesion-induced increase in the proportion of neurons exhibiting both calbindin-D 28kD and tyrosine hydroxylase immunoreactivities, expected if calbindin-D 28kD is neuroprotective, was observed in the substantia nigra, pars compacta, but not in the ventral tegmental area. It is concluded that, while the observed losses of tyrosine hydroxylase and calbindin-D 28kD immunoreactivities do not necessarily reflect neuronal degeneration, they are not consistent with CB confering a neuroprotective advantage in the ventral tegmental area following 6-OHDA lesions as administered in this study.
...
PMID:On the altered expression of tyrosine hydroxylase and calbindin-D 28kD immunoreactivities and viability of neurons in the ventral tegmental area of Tsai following injections of 6-hydroxydopamine in the medial forebrain bundle in the rat. 1086 59

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.
...
PMID:Glial cell line-derived neurotrophic factor stimulates the morphological differentiation of cultured ventral mesencephalic calbindin- and calretinin-expressing neurons. 1087 17

Calbindin-D28k (calbindin) is a calcium-binding protein that is distributed widely in the rat brain. The localisation of calbindin immunoreactivity in the medulla oblongata and its colocalisation with adrenaline-synthesising neurons [phenylethanolamine-N-methyltransferase-immunoreactive (PNMT-IR)] was examined (Granata and Chang [1994] Brain Res. 645:265-277). However, detailed information about the distribution of calbindin-IR neurons in the reticular formation of the medulla oblongata in particular is lacking. In this report, the authors address this issue with an emphasis on the quantitation of calbindin-IR neurons, catecholamine neurons [tyrosine hydroxylase (TH)-IR, or PNMT-IR], and spinally projecting neurons in the ventral brainstem. Rats received injections of the retrograde tracing agent cholera toxin B (CTB) into the thoracic spinal cord or into the superior cervical ganglion. Immunocytochemistry was used to reveal calbindin, TH, PNMT, and CTB immunoreactivity. Ten calbindin-IR cell groups were identified within the pontomedullary reticular formation. Seven previously undescribed but distinct clusters of calbindin-IR neurons were found. Within the ventral pons, a population of calbindin-IR neurons occurred dorsal but adjacent to the A5 cell group. These calbindin-IR neurons did not contain either TH or PNMT immunoreactivity, and few if any of these neurons projected to the spinal cord. A distinct group of calbindin-IR neurons was present in the ventral medulla. Seventy-five percent of these calbindin-IR neurons contained TH immunoreactivity, 45% contained PNMT immunoreactivity, and 21% were spinally projecting neurons. Spinally projecting, calbindin-IR neurons were a subpopulation of PNMT-IR cells. In the caudal ventral medulla, no TH-IR or PNMT-IR cells were calbindin-IR. In the intermediolateral cell column, close appositions of calbindin-IR terminals on identified sympathetic preganglionic neurons as well as calbindin-IR synapses indicated that these neurons may affect directly the sympathetic outflow. The results demonstrate for the first time the existence of a new subpopulation of spinally projecting, PNMT-IR neurons in the rostral ventrolateral medulla.
...
PMID:Calbindin-immunoreactive neurons in the reticular formation of the rat brainstem: catecholamine content and spinal projections. 1090 19

To establish if olfactory bulb sensitivity to functional deprivation is related to the degree of development at birth, we studied the effects of surgical closure of one naris in the gerbil olfactory bulb development. The naris closure was performed at three different ages: at birth, P7 and P14 and maintained for 30 or 60 days. In coronal sections we measured total bulbar surface area and surface area of the different bulbar layers establishing an estimate multiple regression model for the percentage of surface area decrease in the deprived bulb related to non deprived one. The internal and external plexiform layers are the most sensitive layers to deprivation and age and duration of deprivation were factors in their mathematical models. The glomerular layer showed a surface reduction of about 25% without dependence either on age or duration. The deprived glomerular layer showed a much lower tyrosine hydroxylase-immunoreactivity and immunoreactive cell density than those in the non deprived one. However, differences in calbindin-immunoreactive and NADPH-diaphorase positive cell density between deprived and non deprived glomerular layer were not significant. Our results indicate that olfactory bulb sensitivity to functional deprivation is not related to the degree of precocity and changes in age and duration of deprivation cause different effects on the olfactory bulb layers.
...
PMID:Effects of unilateral deprivation in postnatal development of the olfactory bulb in an altricial rodent, the gerbil (Meriones unguiculatus). 1091 3

Basic fibroblast growth factor-responsive neural stem cells (NSCs) derived from adult rat hippocampus were earlier demonstrated to generate neurons and glia. These stem-cell-derived neurons express GABA, acetylcholinesterase, tyrosine hydroxylase, or calbindin. It has not been clear, however, whether or not these stem-cell-derived neurons are able to form functional synapses. In the present study, we investigated the development of synapse formation by adult hippocampus-derived neural stem cells. NSCs from adult rat hippocampi and primary embryonic rat hippocampal neurons were cocultured on a glial feeder layer. Immunofluorescence studies revealed that some of the NSCs became immunoreactive for microtubule-associated protein 2ab, neurofilament 200, synaptobrevin, or synaptophysin. These cells possessed properties of functional neurons such as action potentials and miniature postsynaptic currents (mPSCs). The elicited mPSCs with rapid kinetics were blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX), but not by bicuculline (excitatory mPSCs). The remaining mPSCs had slower kinetics and were blocked by bicuculline, but not by DNQX (inhibitory mPSCs). We considered that the neurons derived from the adult NSCs expressed both non-NMDA glutamate receptors and the GABA(A) receptors and formed functional synapses. Our results demonstrate that adult NSCs can differentiate into neurons with functional glutamatergic and GABAergic synaptic transmission in vitro and support the concept that such neurons could integrate into the neuronal circuitry.
...
PMID:Neurons generated from adult rat hippocampal stem cells form functional glutamatergic and GABAergic synapses in vitro. 1096 86


<< Previous 1 2 3 4 5 6 7 8 9 10

---