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)

In the rat olfactory bulb, the majority of interneurons in the glomerular layer (GL) are supposed to be generated during first postnatal week. Low and repeated doses of X-rays (200 rad x 4 and 200 rad x 6) were used during this period to impair the development of interneurons. The resulting effects of olfactory bulb neurons were examined stereologically and immunocytochemically in animals of 4 and 12 weeks of age. Quantitative analysis showed that, 1) the volume of the GL decreased to 55% (1200 rad) - 70% (800 rad) of control, 2) numerical cell densities in GL decreased to 40% (1200 rad) - 60% (800 rad) of control, thus resulting in 3) a decrease of the total cell number in GL to 20% (1200 rad) - 40% (800 rad) of control in irradiated olfactory bulbs of animals 4 weeks old. In comparison, mitral cells, which are generated prenatally, were much less affected (total cell number: 70-80% of control), indicating a selective loss of cells generated during the first postnatal week in GL. Effects on somata and processes immunoreactive for GABA, tyrosine hydroxylase (TH), calbindin D-28K and parvalbumin (PV) were examined in irradiated bulbs of both 4 and 12 week-old rats. All of these immunoreactive elements showed a drastic decrease in all layers. Semiquantitative analysis showed that in the GL, calbindin D-28K immunoreactive (calbindin D-28K(+)) neurons decreased more extensively than TH immunoreactive (TH(+)) and GABA-like immunoreactive (GABA(+)) neurons; that is, TH(+) and GABA(+) neurons decreased to 20% (1200 rad) - 40% (800 rad) of control, whereas calbindin D-28K(+) neurons decreased to 10% (1200 rad) - 30% (800 rad) of control in the GL of irradiated bulbs. These findings indicated that larger proportions of calbindin D-28K(+) neurons might be generated during the first postnatal week than those of GABA(+) and TH(+) neurons. Furthermore, in irradiated bulbs the proportion of GABA(-)TH(+) cells in TH(+) cells increased to about twice of control, and the estimated total numbers of GABA(-)TH(+) cells in irradiated rats were 95% (800 rad) and 40% (1200 rad) of control. These observations suggest that the majority of GABA(-)TH(+) neurons were less affected by X-ray irradiation during the first postnatal week and thus that they might be generated in the prenatal period. Since during the first 2 postnatal weeks, neurons showing GABA(-)TH(+) were not seen in GL (Kosaka et al. 1987a), the majority of GABA(-)TH(+) neurons in adult olfactory bulb were assumed to change their phenotype at some postnatal developmental period.
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PMID:Postnatal X-ray irradiation effects on glomerular layer of rat olfactory bulb: quantitative and immunocytochemical analysis. 135 42

Counts performed on dissociated cell cultures of E10 chick embryo dorsal root ganglia (DRG) showed after 4-6 days of culture a pronounced decline of the neuronal population in neuron-enriched cultures and a net gain in the number of ganglion cells in mixed DRG cell cultures (containing both neurons and nonneuronal cells). In the latter case, the increase in the number of neurons was found to depend on NGF and to average 119% in defined medium or 129% in horse serum-supplemented medium after 6 days of culture. The lack of [3H]thymidine incorporation into the neuronal population indicated that the newly formed ganglion cells were not generated by proliferation. On the contrary, the differentiation of postmitotic neuroblasts present in the nonneuronal cell compartment was supported by sequential microphotographs of selected fields taken every hour for 48-55 hr after 3 days of culture. Apparently nonneuronal flat dark cells exhibited morphological changes and gradually evolved into neuronal ovoid and refringent cell bodies with expanding neurites. The ultrastructural organization of these evolving cells corresponded to that of primitive or intermediate neuroblasts. The neuronal nature of these rounding up cell bodies was indeed confirmed by the progressive expression of various neuronal cell markers (150 and 200-kDa neurofilament triplets, neuron specific enolase, and D2/N-CAM). Besides a constant lack of immunoreactivity for tyrosine hydroxylase, somatostatin, parvalbumin, and calbindin-D 28K and a lack of cytoenzymatic activity for carbonic anhydrase, all the newly produced neurons expressed three main phenotypic characteristics: a small cell body, a strong immunoreactivity to MAG, and substance P. Hence, ganglion cells newly differentiated in culture would meet characteristics ascribed to small B sensory neurons and more specifically to a subpopulation of ganglion cells containing substance P-immunoreactive material.
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PMID:Differentiation of postmitotic neuroblasts into substance P-immunoreactive sensory neurons in dissociated cultures of chick dorsal root ganglion. 243 96

The organization of the GABAergic system in the rat main olfactory bulb was investigated immunohistochemically using antisera against glutamic acid decarboxylase (GAD), tyrosine hydroxylase (TH), parvalbumin (PV) and methionin-enkephalin-Arg6-Gly7-Leu8 (ENK). Some GABAergic neurons were shown to contain TH immunoreactivity in the glomerular layer, PV immunoreactivity in the external plexiform layer and ENK-like immunoreactivity in the granule cell layer, indicating the stratified organization of the GABAergic subsystems.
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PMID:An aspect of the organization of the GABAergic system in the rat main olfactory bulb: laminar distribution of immunohistochemically defined subpopulations of GABAergic neurons. 288 84

The aim of this study was to investigate the neurochemical coding of myenteric neurons in the guinea pig gastric corpus by using immunohistochemical methods. Antibodies and antisera against calbindin (CALB), calretinin (CALRET), choline acetyltransferase (ChAT), calcitonin gene-related peptide (CGRP), dopamine beta-hydroxylase (DBH), beta-endorphin (ENK), neuropeptide Y (NPY), neuron-specific enolase (NSE), nitric oxide synthase (NOS), protein gene product 9.5 (PGP), parvalbumin (PARV), serotonin (5-HT), somatostatin (SOM), substance P (SP), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP) were used. Double- and triple-labeling studies revealed colocalization of certain transmitters and enabled the identification of distinct subpopulations of gastric enteric neurons. NPY/VIP/NOS/ENK were present in 28% of all neurons, whereas 11% had NPY/VIP/DBH/ChAT; NOS-only neurons made up 2% of the population. The combination SP/ChAT/ENK occurred in 21% of the population, whereas SP/ChAT/ENK/CALRET and SP/CHAT/SOM/ +/- CALRET was identified in 5% and 6% of all cells, respectively. 5-HT-containing neurons comprised 2% of all cells and could be further classified by the presence of additional antigens as 5-HT/SP/(ChAT) or 5-HT/VIP/(ChAT). Approximately 21% of all neurons contained only ChAT with no additional antigen present and are referred to as ChAT/-. Gastric myenteric ganglion cells were not immunoreactive for CALB, PARV, CGRP, or TH. The results of this study indicate that gastric myenteric neurons can be characterized on the basis of different chemical coding. Neurochemical coding of corpus myenteric neurons revealed some similarities and significant differences in comparison with other regions of the gut. These differences might reflect adaptation of enteric nerves according to regional specialization and the distinct functions of the proximal stomach as a gastric reservoir.
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PMID:Neurochemical coding of enteric neurons in the guinea pig stomach. 753 52

Gangliogliomas, dysembryoplastic neuroepithelial tumors (DNT) and glioneuronal malformations are frequently encountered in patients with pharmacoresistant focal epilepsies. In order to characterize the neurochemical profile of these neoplastic and malformative glioneuronal lesions, we have examined the presence of the alpha 1 subunit of the GABAA receptor, the N-methyl-D-aspartate receptor subunit 1 (NR1), glutamate decarboxylase, tyrosine hydroxylase, somatostatin, parvalbumin, and calretinin in 60 gangliogliomas, 11 DNT, 10 tuberous sclerosis-like lesions and 17 non-tuberous sclerosis-like glioneuronal malformations. All DNT and tuberous sclerosis-like lesions, 59 gangliogliomas (98%), and 13 non-tuberous sclerosis-like hamartias (76%) were positive for at least one of the markers. Despite a great variation between and within the different entities, the neurochemical profile was generally reminiscent of normal neocortex: glutamate decarboxylase, GABAA receptor and NR1 which are common in neocortical neurons were present in the great majority of the lesions and often showed high labeling indices. There were three tuberous sclerosis-like lesions (30%) that contained both NR1 and glutamate decarboxylase immunoreactive giant cells in addition to well-differentiated ganglion cells. This supports the idea that at least some of these giant cells are of neuronal origin. The oligodendroglia-like cells of DNT and glioneuronal hamartias did not show immunoreactivity for any of the markers. The very high incidence of ganglioglial lesions in patients with chronic focal epilepsies and the presence of neurotransmitter-producing enzymes, neurotransmitter receptors, neuropeptides, and calcium-binding proteins in many of these lesions suggests that they may play an active role in the pathogenesis of epileptic seizures.
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PMID:Neurochemical profile of glioneuronal lesions from patients with pharmacoresistant focal epilepsies. 766 58

Parvalbumin- and calbindin D-28k-immunoreactivities (ir) were examined in the glossopharyngeal and vagal sensory ganglia (petrosal, nodose and jugular ganglia), the carotid sinus nerve and the carotid body. Parvalbumin-ir nerve cells were mostly localized in the petrosal and nodose ganglia and were rare in the jugular ganglion. Calbindin D-28k-ir nerve cells were found in moderate and large numbers in the petrosal and nodose ganglia, respectively. Only a few calbindin D-28k-ir nerve cells were observed in the jugular ganglion. The carotid sinus nerve and carotid body contained numerous calbindin D-28k-ir nerve fibers but few parvalbumin-ir nerve fibers. Studies of the coexistence of these calcium-binding proteins with calcitonin gene-related peptide (CGRP)- and tyrosine hydroxylase (TH)-ir showed that CGRP-ir was rarely colocalized in parvalbumin- or calbindin D-28k-ir nerve cells in the petrosal or nodose ganglion. Moreover, TH-ir was not generally contained in parvalbumin-ir nerve cells in the petrosal, nodose and jugular ganglia while a portion (15-19%) of calbindin D-28k-ir neurons in the petrosal and nodose ganglia colocalized TH-ir. These findings are consistent with the involvement of calcium-binding proteins, particularly calbindin D-28k, in the function of visceral sensory neural systems of the glossopharyngeal and vagus nerves and, perhaps, in baro- and chemoreceptor neurotransmission.
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PMID:Parvalbumin and calbindin D-28k in vagal and glossopharyngeal sensory neurons of the rat. 779 49

The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100 beta. Calbindin D28k and S-100 beta appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, gamma-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse.
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PMID:Cytochemical characteristics of neurons in the trigeminal mesencephalic nucleus of hatchling chicks. 788 44

A number of neuroendocrine and neuronal markers were demonstrated in Leydig cells of the testes of 18 men aged between 20 and 81 years. Tissue sections were divided into five groups, i.e. carcinoma of the prostate (control cases; n = 4), seminoma (n = 8), anti-androgen therapy (n = 3), oestradiol therapy (n = 2) and cryptorchidism (n = 1). The following substances were immunocytochemically tested: the monoamine synthesizing enzymes tyrosine hydroxylase, aromatic L-amino acid decarboxylase, dopamine-beta-hydroxylase and phenylethanolamine-N-methyltransferase, the indolamine serotonin, the calcium-binding proteins parvalbumin, calbindin and S-100 protein, the microtubule associated protein-2, as well as neurofilament protein 200, synaptophysin, neuron specific enolase, substance P and chromogranin A + B. All these substances were found in Leydig cells of all sections independently of the pathological changes of the testes. Compared with the control cases, all the other groups showed a significantly weaker immunoreactivity for all markers. The uniformity of staining among the different antibodies allows the deduction that these neuroactive peptides may belong to a basic equipment of Leydig cells probably stabilizing their function in an autocrine manner. On the other hand, Leydig cells themselves seem to be a stable structural component of the testis, which are not essentially involved in the pathogenesis of the disturbances mentioned above.
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PMID:Neuroendocrine marker substances in human Leydig cells--changes by disturbances of testicular function. 790 79

Saccadic omnipause neurons (OPNs) are essential for the generation of saccadic eye movements. In primates OPNs are located near the midline within the nucleus raphe interpositus (rip). In the present study we used several different neuroanatomical methods to investigate the transmitters associated with OPNs in the monkey. Immunolabeling for the calcium-binding protein parvalbumin was employed to mark OPNs in the monkey and define the homologous cell group in cat and human. The use of antibodies against GABA, glycine (GLY), glutamate (GLU), serotonin (5-HT), and tyrosine hydroxylase revealed that the somata of OPNs are GLY immunoreactive, but they are devoid of GABA and 5-HT immunostaining. In situ hybridization with the GAD67 mRNA probe confirmed the negative GABA immunostaining of OPNs. 3H-GLY was injected into a projection field of OPNs, the rostral interstitial nucleus of the medial longitudinal fascicle (riMLF)--the vertical saccadic burst neuron area. This resulted in selective retrograde labeling of the OPNs in rip, while no labeling was found in the superior colliculus, which sends an excitatory projection to the riMLF. The somata and dendrites of putative burst neurons in the riMLF were contacted by numerous GLY-immunoreactive terminals. The quantitative analysis of immunoreactive terminal-like structures contacting OPNs revealed a strong input from GLY- and GABA-positive terminals on somata and dendrites, whereas GLU-positive puncta were mainly confined to the dendrites. Very few 5-HT and catecholaminergic terminals contacted OPN somata. Our findings suggest that OPNs use GLY as a neurotransmitter, and they receive numerous contacts from GABAergic, glycinergic, and glutaminergic afferents, and significantly fewer from monoaminergic inputs.
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PMID:Neurotransmitter profile of saccadic omnipause neurons in nucleus raphe interpositus. 790 56

Material for the study came from one 126 day-old rhesus monkey fetus and two 3 day-old neonates. The immunocytochemical detection of somatostatin, neurotensin (NT), parvalbumin, calbindin D-28K, DARPP-32 as well as tyrosine hydroxylase (TH), dopamine-beta-hydroxylase and serotonin (5-HT), was carried out on serial cryostat sections of the entorhinal cortex. The authors reported in a previous paper the precocious differentiation of the entorhinal cortex in rhesus monkey fetuses and featured the conspicuous expression of calbindin D-28K, somatostatin, neurotensin, and the monoaminergic innervation during the first half of gestation. The present study shows distinct temporal profiles of neurochemical development during the second half of gestation: the dense neuropeptidergic innervation remained a constant feature; the three aminergic systems gradually increased in density; parvalbumin, unlike calbindin D-28K, was primarily expressed during the last quarter of gestation. Three other prominent features of the last quarter of gestation are illustrated: the refinement of the modular neurochemical organization of the lamina principalis externa, the delayed chemoanatomical development of the rhinal sulcus area, and the establishment of a distinct rostrocaudal pattern of neurochemical distribution. In correspondence with the cluster-like organization of the lamina principalis externa, the authors observed in the olfactory, rostral, and intermediate fields of the neonate monkey entorhinal cortex, a particular subset of pyramidal-shaped neurons: located in layer III, they were characterized by fasciculated apical dendrites ascending between the cellular islands of the discontinuous layer II and the coexpression of calbindin D-28K and DARPP-32. Besides, most of the other chemical systems displayed a distinct, area-specific, patchy distribution, except for the homogeneously distributed noradrenergic innervation. In the olfactory and rostral fields, TH positive dopaminergic fibers accumulated on the neuronal islands of layers II-III, and parvalbumin labeled fibers on those of layer III, whereas patches of 5-HT and NT-like reactive terminals were segregated between the cellular islands, overlapping the DARPP-32/calbindin D-28 K labeled dendritic bundles. At the opposite, in the intermediate field, 5-HT positive terminals overlapped the cellular islands of layer II and thin fascicles of dopaminergic fibers ran in the inter island spaces. The somatostatin-LIR innervation was apparently too dense to reveal a patchy distribution that existed at earlier developmental stages. In the caudal field, the patchy pattern was replaced by a predominant bilaminar type of distribution of NT, 5-HT, and TH-like positive afferents.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neurochemical development of the hippocampal region in the fetal rhesus monkey. II. Immunocytochemistry of peptides, calcium-binding proteins, DARPP-32, and monoamine innervation in the entorhinal cortex by the end of gestation. 791 99


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