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

Developmental changes of the distribution pattern of substance P receptor (SPR) were investigated immunohistochemically in the rat striatum. The SPR immunoreactivity in the striatum first emerged at postnatal day 1 and transiently showed a patchy pattern of distribution until it displayed the adult pattern of homogeneous distribution by the third postnatal week. The SPR-immunoreactivity patches were most marked in the medial and dorsolateral parts of the striatum, as well as in the subcallosal streak. They matched tyrosine hydroxylase-enriched areas and, conversely, avoided calbindin-enriched zones. No neurons within the SPR-immunoreactive patches contained either choline acetyltransferase or somatostatin, which is known to be contained in intrinsic neurons in the striatum. The vast majority of SPR-immunoreactive patch neurons also contained DARPP-32, a phosphoprotein that is expressed in striatal projection neurons with D1 dopamine receptor. The results indicate that SPR-immunoreactive patches which appear transiently in the developing striatum are in register with the striatal patch compartment, and that SPR immunoreactivity within these patches may be expressed on projection neurons rather than intrinsic neurons. Such SPR immunoreactivity in projection neurons in striatal patches may fade out in adulthood.
...
PMID:Patchy distribution of substance P receptor immunoreactivity in the' developing rat striatum. 887 81

The distributions of dopamine D1 receptors, dopaminoceptive neurons, and catecholaminergic fibers were investigated in the forebrain of the domestic chick by using D1 receptor autoradiography and immunohistochemical detection of D1 receptor protein (D1rp), the dopamine- and cAMP-regulated phosphoprotein DARPP-32, and tyrosine hydroxylase (TH). Particular attention was paid to two forebrain regions, the mediorostral neostriatum/ hyperstriatum ventrale (MNH) and neostriatum dorsocaudale (Ndc), which have been shown to be crucially involved in filial imprinting. In general, there was a good, but not complete, correlation between the immunohistochemical pattern of DARPP-32 positive perikarya and the distribution of D1 receptors. Both, DARPP-32 positive neurons as well as D1 receptors were highly enriched in the striatal part of the basal ganglia including the lobus parolfactorius (LPO) and paleostriatum augmentatum. High to moderate densities were observed in the outer rind of the pallium. Low to moderate densities were found in the belt regions of primary sensory areas, whereas densities in the respective core regions were generally low. Labeling in the MNH and Ndc was heterogeneous. Whereas the neostriatal part of MNH displayed both, moderate DARPP-32 immunostaining and moderate D1 receptor densities, the hyperstriatal part showed also moderate D1 receptor densities but was only weakly labeled by DARPP-32. The rostral part of the Ndc was among the most intensely DARPP-32 labeled areas of the pallium, its caudal part revealed only moderate DARPP-32 immunostaining. By using D1 receptor autoradiography, a homogeneous labeling throughout the rostrocaudal extension of the Ndc was found. Double-labeling experiments with antibodies to DARPP-32 and TH revealed that TH positive fibers in the MNH, Ndc, and LPO were often closely related to DARPP-32 positive perikarya. At the ultrastructural level, both immunoreaction for D1rp and DARPP-32 in the MNH and Ndc were primarily found to be associated with postsynaptic elements. Whereas D1rp immunoreactivity was enriched at postsynaptic densities or in their vicinity, reaction product for DARPP-32 was present throughout the perikaryal cytoplasm, dendrites, and dendritic spines. These results indicate that DARPP-32 as well as D1 receptors in the avian forebrain reveal a distribution that is substantially similar to that of mammals.
...
PMID:Localization of dopamine D1 receptors and dopaminoceptive neurons in the chick forebrain. 936 44

Dopaminergic axons arising from midbrain nuclei innervate the mammalian and avian telencephalon with heterogeneous regional and laminar distributions. In primate, rodent, and avian species, the neuromodulator dopamine is low or almost absent in most primary sensory areas and is most abundant in the striatal parts of the basal ganglia. Furthermore, dopaminergic fibres are present in most limbic and associative structures. Herein, the distribution of DARPP-32, a phosphoprotein related to the dopamine D1-receptor, was investigated in the pigeon telencephalon by immunocytochemical techniques. Furthermore, co-occurrence of DARPP-32-positive perikarya with tyrosine hydroxylase-positive pericellular axonal "baskets" or glutamate decarboxylase-positive neurons, as well as co-occurrence of tyrosine hydroxylase and glutamate decarboxylase were examined. Specificity of the anti-DARPP-32 monoclonal antibody in pigeon brain was determined by immunoblotting. The distribution of DARPP-32 shared important features with the distribution of D1-receptors and dopaminergic fibres in the pigeon telencephalon as described previously. In particular, DARPP-32 was highly abundant in the avian basal ganglia, where a high percentage of neurons were labelled in the "striatal" parts (paleostriatum augmentatum, lobus parolfactorius), while only neuropil staining was observed in the "pallidal" portions (paleostriatum primitivum). In contrast, DARPP-32 was almost absent or present in comparatively lower concentrations in most primary sensory areas. Secondary sensory and tertiary areas of the neostriatum contained numbers of labelled neurons comparable to that of the basal ganglia and intermediate levels of neuropil staining. Approximately up to one-third of DARPP-32-positive neurons received a basket-type innervation from tyrosine hydroxylase-positive fibres in the lateral and caudal neostriatum, but only about half as many did in the medial and frontal neostriatum, and even less so in the hyperstriatum. No case of colocalization of glutamate decarboxylase and DARPP-32 and no co-occurrence of glutamate decarboxylase-positive neurons and tyrosine hydroxylase-basket-like structures could be detected out of more than 2000 glutamate decarboxylase-positive neurons examined, although the high DARPP-32 and high tyrosine hydroxylase staining density hampered this analysis in the basal ganglia. In conclusion, the pigeon dopaminergic system seems to be organized similar to that of mammals. Apparently, in the telencephalon, dopamine has its primary function in higher level sensory, associative and motor processes, since primary areas showed only weak or no anatomical cues of dopaminergic modulation. Dopamine might exert its effects primarily by modulating the physiological properties of non-GABAergic and therefore presumably excitatory units.
...
PMID:The dopaminergic innervation of the pigeon telencephalon: distribution of DARPP-32 and co-occurrence with glutamate decarboxylase and tyrosine hydroxylase. 948 60

Neural and stem cell transplantation is emerging as a potential treatment for neurodegenerative diseases. Transplantation of specific committed neuroblasts (fetal neurons) to the adult brain provides such scientific exploration of these new potential therapies. Huntington's disease (HD) is a fatal, incurable autosomal dominant (CAG repeat expansion of huntingtin protein) neurodegenerative disorder with primary neuronal pathology within the caudate-putamen (striatum). In a clinical trial of human fetal striatal tissue transplantation, one patient died 18 months after transplantation from cardiovascular disease, and postmortem histological analysis demonstrated surviving transplanted cells with typical morphology of the developing striatum. Selective markers of both striatal projection and interneurons such as dopamine and c-AMP-related phosphoprotein, calretinin, acetylcholinesterase, choline acetyltransferase, tyrosine hydroxylase, calbindin, enkephalin, and substance P showed positive transplant regions clearly innervated by host tyrosine hydroxylase fibers. There was no histological evidence of immune rejection including microglia and macrophages. Notably, neuronal protein aggregates of mutated huntingtin, which is typical HD neuropathology, were not found within the transplanted fetal tissue. Thus, although there is a genetically predetermined process causing neuronal death within the HD striatum, implanted fetal neural cells lacking the mutant HD gene may be able to replace damaged host neurons and reconstitute damaged neuronal connections. This study demonstrates that grafts derived from human fetal striatal tissue can survive, develop, and are unaffected by the disease process, at least for 18 months, after transplantation into a patient with HD.
...
PMID:Transplanted fetal striatum in Huntington's disease: phenotypic development and lack of pathology. 1113 40

To assess the relationship between dopaminergic neuronal structures and dopaminoceptive structures in a reptile, single and double immunohistochemical procedures with antibodies directed against DARPP-32 (dopamine- and cAMP-regulated phosphoprotein with an apparent molecular mass of 32,000 daltons),a phosphoprotein related to the dopamine D(1)-receptor, and tyrosine hydroxylase (TH) were applied to the brain of the lizard, Gekko gecko. The DARPP-32 antibody yielded a well-differentiated pattern of staining in the brain of Gekko. In general, areas that are densely innervated by TH-immunoreactive, putative dopaminergic fibers, such as the nucleus accumbens, striatum, dorsal ventricular ridge, and amygdaloid complex, display strong immunoreactivity for DARPP-32 in somata and neuropil. Distinct cellular DARPP-32 immunoreactivity was also found in the lateral cortex, ventral hypothalamus, habenula, central nucleus of the torus semicircularis, midbrain tectum, parvicellular isthmic nucleus, raphe nuclei, caudal rhombencephalic tegmentum, and spinal cord. Striatal projections to the midbrain and their target, i.e., the substantia nigra pars reticulata, were found to be strongly immunoreactive. Double immunofluorescence staining revealed that dopaminergic cells generally do not stain for DARPP-32, except for cells in the ventral hypothalamus and at caudal rhombencephalic levels. In conclusion, the distribution of DARPP-32 in the brain of the lizard Gekko gecko largely resembles the pattern observed in birds and mammals, at least as far as basal ganglia structures are concerned. On the other hand, there are several specific features of DARPP-32 distribution in the gekkonid brain that deserve further attention, such as cellular colocalization of DARPP-32 and TH immunoreactivity in hypothalamic and caudal rhombencephalic areas, and cellular DARPP-32 immunoreactivity in the tectum and central nucleus of the torus semicircularis of the midbrain, the superior and inferior raphe nuclei, and the spinal cord.
...
PMID:Immunohistochemical localization of DARPP-32 in the brain of the lizard, Gekko gecko: co-occurrence with tyrosine hydroxylase. 1139 41

Hodological, electrophysiological, and ablation studies indicate a role for the basal forebrain in telencephalic vocal control; however, to date the organization of the basal forebrain has not been extensively studied in any nonmammal or nonhuman vocal learning species. To this end the chemical anatomy of the avian basal forebrain was investigated in a vocal learning parrot, the budgerigar (Melopsittacus undulatus). Immunological and histological stains, including choline acetyltransferase, acetylcholinesterase, tyrosine hydroxylase, dopamine and cAMP-regulated phosphoprotein (DARPP)-32, the calcium binding proteins calbindin D-28k and parvalbumin, calcitonin gene-related peptide, iron, substance P, methionine enkephalin, nicotinamide adenine dinucleotide phosphotase diaphorase, and arginine vasotocin were used in the present study. We conclude that the ventral paleostriatum (cf. Kitt and Brauth [1981] Neuroscience 6:1551-1566) and adjacent archistriatal regions can be subdivided into several distinct subareas that are chemically comparable to mammalian basal forebrain structures. The nucleus accumbens is histochemically separable into core and shell regions. The nucleus taeniae (TN) is theorized to be homologous to the medial amygdaloid nucleus. The archistriatum pars ventrolateralis (Avl; comparable to the pigeon archistriatum pars dorsalis) is theorized to be a possible homologue of the central amygdaloid nucleus. The TN and Avl are histochemically continuous with the medial aspects of the bed nucleus of the stria terminalis and the ventromedial striatum, forming an avian analogue of the extended amygdala. The apparent counterpart in budgerigars of the mammalian nucleus basalis of Meynert consists of a field of cholinergic neurons spanning the basal forebrain. The budgerigar septal region is theorized to be homologous as a field to the mammalian septum. Our results are discussed with regard to both the evolution of the basal forebrain and its role in vocal learning processes.
...
PMID:Organization of the avian basal forebrain: chemical anatomy in the parrot (Melopsittacus undulatus). 1245 5

Dopamine D2 receptors are highly expressed in the dorsal striatum where they participate in the regulation of (i) tyrosine hydroxylase (TH), in nigrostriatal nerve terminals, and (ii) the dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), in medium spiny neurons. Two isoforms of the D2 receptor are generated by differential splicing of the same gene and are referred to as short (D2S) and long (D2L) dopamine receptors. Here we have used wild-type mice, dopamine D2 receptor knockout mice (D2 KO mice; lacking both D2S and D2L receptors) and D2L receptor-selective knockout mice (D2L KO mice) to evaluate the involvement of each isoform in the regulation of the phosphorylation of TH and DARPP-32. Incubation of striatal slices from wild-type mice with quinpirole, a dopamine D2 receptor agonist, decreased the state of phosphorylation of TH at Ser-40 and its enzymatic activity. Both effects were abolished in D2 KO mice but were still present in D2L KO mice. In wild-type mice, quinpirole inhibits the increase in DARPP-32 phosphorylation at Thr-34 induced by SKF81297, a dopamine D1 receptor agonist. This effect is absent in D2 KO as well as D2L KO mice. The inability of quinpirole to regulate DARPP-32 phosphorylation in D2L KO mice cannot be attributed to decreased coupling of D2S receptors to G proteins, because quinpirole produces a similar stimulation of [(35)S]GTPgammaS binding in wild-type and D2L KO mice. These results demonstrate that D2S and D2L receptors participate in presynaptic and postsynaptic dopaminergic transmission, respectively.
...
PMID:Distinct roles of dopamine D2L and D2S receptor isoforms in the regulation of protein phosphorylation at presynaptic and postsynaptic sites. 1265 45

A previous study in the lizard Gekko gecko has revealed that the distribution of DARPP-32 (a phosphoprotein related to the dopamine D(1)-receptor) largely resembles the pattern observed in birds and mammals, at least as far as basal ganglia structures are concerned. On the other hand, several specific features of DARPP-32 distribution in the gekkonid brain were noted that deserved further attention, e.g. cellular co-localization of DARPP-32 and tyrosine hydroxylase (TH) immunoreactivity in hypothalamic and caudal rhombencephalic areas. To assess the primitive or derived character of these features, DARPP-32 and TH antibodies have been applied to the brain of the turtle, Pseudemys scripta elegans, which belongs to a different radiation of reptiles. Areas in Pseudemys that are densely innervated by TH-immunoreactive fibers, such as the striatum and amygdaloid complex, display strong immunoreactivity for DARPP-32 in somata and neuropil. Strongly immunoreactive fiber plexuses were found in the substantia nigra pars reticulata and in the ventromedial part of the rhombencephalon. Cellular co-localization of DARPP-32 and TH was observed in the ventral hypothalamus but, in contrast to Gekko, not at caudal rhombencephalic levels. Moreover, cellular DARPP-32 immunoreactivity was not seen in the raphe nuclei and spinal cord of Pseudemys. Other notable species differences in DARPP-32 distribution were found in the olfactory bulb, dorsal ventricular ridge and pretectum. In conclusion, the present account on the distribution of DARPP-32 in Pseudemys confirms and extends previous findings in a gekkonid lizard. At the same time, however, it demonstrates that substantial species differences exist, some of which may be related to differences previously observed in the dopaminergic systems.
...
PMID:Immunohistochemical localization of DARPP-32 in the brain of the turtle, Pseudemys scripta elegans: further assessment of its relationship with dopaminergic systems in reptiles. 1266 57

The phenotypic expression of behaviour is the outcome of interacting neuronal networks and is modulated by different subcortical systems. In the present paper the role of a major subcortical neurochemical system, dopamine (DA), is reviewed. In particular, knockout (KO) technology has given an overwhelming insight into the effects of specific component of the dopaminergic system. Therefore, the behavioural profile of dopamine transporter (DAT), tyrosine hydroxylase (TH), DA and cAMP-regulated phosphoprotein (DARPP 32), and D1, D2, D3, D4 and D5 dopamine receptors knockouts (and their combination) is reviewed.TH, D1, D2, D4 KO mice exhibit decreased locomotor activity, perhaps due to decreased motivational level. D3 KO and DAT KO mice show an increase in basal and novelty-induced activity respectively. It is possible that the increased dopamine levels in DAT KO mice enhance motivation. These observations support the hyperDA hypothesis in hyperactive phenotypes. Moreover, they suggest that the inhibitory effect of psychostimulant drugs, such as methylphenidate and amphetamines, in Attention Deficit Hyperactivity Disorder may be the outcome of an altered balance between auto- and hetero-receptors. However, since KO technology is hampered by blockade of the target at early stages of development, some alternatives have been proposed, such as inducible mutagenesis and inhibitory small RNAs conveyed to target by viral vectors in adulthood.
...
PMID:Dopamine phenotype and behaviour in animal models: in relation to attention deficit hyperactivity disorder. 1462 7

In the present study we assessed the neuroprotective effects of the pan-caspase inhibitor z-VAD.fmk [N-benzyloxycarbony-valine-alanine-aspartate-(OMe)-fluoromethylketone], and the caspase-3 inhibitor Ac-DEVD.CHO (acetyl-aspartate-chloromethylketone) in the double-lesion rat model of striatonigral degeneration (SND), the core pathology underlying levodopa-unresponsive parkinsonism associated with multiple system atrophy (MSA). Male Wistar rats were divided into three groups, receiving either Ac-DEVD.CHO, z-VAD.fmk or normal saline before lesion surgery, comprising a sequential unilateral quinolinic acid (QA) lesion of the striatum followed by a 6-hydroxydopamine (6-OHDA) lesion of the ipsilateral medial forebrain bundle. At 2 weeks post lesion, all rats underwent testing of spontaneous nocturnal locomotor behavior in an automated Photobeam Activity System (FlexField). Immunohistochemistry was performed with tyrosine hydroxylase, dopamine and cyclic adenosine 3',5'-monophosphate-regulated phosphoprotein and glial fibrillary acidic protein antibodies. Morphometry was performed using computerized image analysis. Behavioral and morphological analysis failed to show striatal or nigral protection in caspase inhibitor-treated animals. Our findings suggest that anti-apoptotic strategies are unrewarding in the SND rat model and, therefore, alternative neuroprotective interventions such as anti-glutamatergic agents or inhibitors of microglial activation should be explored instead.
...
PMID:Failure of caspase inhibition in the double-lesion rat model of striatonigral degeneration (multiple system atrophy). 1554 30


<< Previous 1 2 3 4 5 6 7 Next >>