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M A Ariano

Publications and source records attributed to M A Ariano.

54 records · Page 3Linked to original sources
PubMed1985

Peptide coincidence in rat superior cervical ganglion.

The immunofluorescent localization of substance P (SP), somatostatin and methionine enkephalin has been determined in the rat superior cervical ganglion of the sympathetic nervous system. Immunoreactivity was confined to the norepinephrine-containing post-ganglionic neurons and their processes. Nearly 20% of the postganglionic somata demonstrate dual coincidence in staining for SP-somatostatin, somatostatin-enkephalin, or SP-enkephalin. Almost 10% of the positively stained neurons show a coincident staining of all 3 peptide compounds within their somata. This suggests that multiple neurotransmitter chemicals may be employed by the postganglionic cells of the superior cervical ganglion.

Animals↗
PubMed1985

Muscarinic acetylcholine receptors are localized on striatal cyclic GMP-containing neurons.

The localization of muscarinic acetylcholine receptors has been determined using in vitro binding of radiolabeled quinuclidinyl benzilate ([3H]QNB), a specific reversible muscarinic receptor antagonist. All cyclic GMP-immunoreactive neurons in the rat striatum show clustering of [3H]QNB silver grains overlying their somata following autoradiographic analysis. The autoradiography of total binding of silver grains over the cyclic GMP-containing neurons was approximately 800 times as dense as the surrounding neuropil localization of radioligand binding sites. Incubation of striatal tissue slices in the presence of micromolar atropine, to determine non-specific binding of [3H]QNB, decreased the autoradiographic silver grain density of the neuropil about 2.5 times, and lessened the number of receptor sites detectable on cyclic GMP-positive neurons at least 5-fold. Biochemical examination of [3H]QNB binding on tissue sections demonstrated that the ligand binding is saturable and dependent on section thickness for the muscarine receptor subtype of acetylcholine.

Animals↗
PubMed1985

Neurotransmitter receptor autoradiography in immunohistochemically identified neurons.

A method for the simultaneous visualization of neurotransmitter receptor binding sites and immunohistochemically characterized cells is described using in vitro sections of rat striatum. The striatum provides a rich neurochemical environment in which to examine muscarinic acetylcholine receptor relations to peptide-reactive somata, or to assess the cellular locale of the dopamine receptor linked to adenylate cyclase activation. Different modifications of the procedure are employed to determine the localization pattern of 3H-radioligands with slow or rapid receptor dissociation times. The present technique is compatible for use with any combination of immunohistochemical antibody/radioligand probe that can be studied on fresh-frozen, slide-mounted tissue sections.

Animals↗
PubMed1984

Rat striatal cyclic nucleotide-reactive cells and acetylcholinesterase reactive interneurons are separate populations.

The concurrent localization of cyclic nucleotide immunofluorescent cells and acetylcholinesterase-containing neurons in the rat caudate-putamen complex has been examined. Cyclic AMP and cyclic GMP stained elements do not exhibit coincident localization with the enzymatically detectable hydrolysis of acetylcholine. These data add further support for the preferential association of the cyclic nucleotides with striatal efferent projection systems, while the large cholinergic somata are part of the interneuron population of the rat caudate-putamen complex.

Acetylcholinesterase↗
PubMed1983

Co-localization of cyclic GMP in superior cervical ganglion with peptide neurotransmitters.

The immunofluorescent localization of cyclic 3',5'-guanosine monophosphate (cyclic GMP) in rat superior cervical ganglion has been compared to postganglionic neurons having immunoreactivity to neuropeptides. Cyclic GMP-positive somata are equally distributed among cell bodies fluorescent for substance P, somatostatin, and methionine-enkephalin. 40% of the total number of cells stained for each peptide demonstrate co-incident cyclic GMP localization, suggesting a large majority of the neurons employ non-cyclic GMP mechanisms.

Animals↗
PubMed1983

Cyclic nucleotide distribution within rat striatonigral neurons.

Adenosine cyclic 3',5'-monophosphate and guanosine cyclic 3',5'-monophosphate have differential immunohistochemical distributions within retrogradely-labeled striatonigral neurons of the rat. Adenosine cyclic 3',5'-monophosphate is localized within more than half of the striatonigral projection neurons. It is also within the cytoplasm of other neurons and oligodendroglia. Guanosine cyclic 3'-5'-monophosphate is localized within 80% of the identified striatonigral neurons. These large percentages of cyclic nucleotide immunoreactivity within the striatonigral neurons suggest some of these efferent cells must contain both cyclic nucleotides. The immunofluorescent staining for guanosine cyclic 3',5'-monophosphate is almost identical to that reported for efferent neurotransmitter-containing neurons of the caudate nucleus. However, the large proportion of striatonigral neurons demonstrating guanosine cyclic 3',5'-monophosphate immunoreactivity precludes the association of the cyclic nucleotide with a selective neurotransmitter agent. Adenosine cyclic 3',5'-monophosphate-reactive elements are very different in staining appearance from guanosine cyclic 3',5'-monophosphate and neurotransmitter-identified somata. The number of striatonigral cells exhibiting reaction for this cyclic nucleotide does not eliminate the possibility that adenosine cyclic 3',5'-monophosphate might be preferentially co-localized with a specific neurotransmitter, such as gamma-aminobutyrate, as has been previously suggested through biochemical experimentation.

Animals↗
PubMed1983

Distribution of components of the guanosine 3',5'-phosphate system in rat caudate-putamen.

The cellular distribution of guanylate cyclase (EC 4.6.1.2), guanosine 3',5'-phosphate (cyclic GMP), cyclic GMP-dependent protein kinase (EC 2.7.1.38), and cyclic GMP phosphodiesterase (EC 3.1.4.17) have been examined in the rostral rat caudate-putamen complex. Immunofluorescent staining for guanylate cyclase, cyclic GMP, and cyclic GMP-dependent protein kinase in fresh frozen caudate-putamen tissues is analogous to the immunoperoxidase localization in perfusion-fixed striatal slices. Homologous immunoreactivity in the cytoplasm and processes of ovoid and rounded neurons, 15-20 microns in diameter can be seen for these three components of the cyclic GMP system. Immunoreactive neurons are uniformly distributed throughout the caudate-putamen complex of all experimental tissue examined. Occasional large neurons, greater than 25 microns in diameter, in the ventral region of the striatum show immunoreactivity. Enzyme histochemical determination of the activities of guanylate cyclase and cyclic GMP phosphodiesterase show the medium-sized neuronal population (15-20 microns) contain hydrolytic activity for these proteins. Large- to medium-sized capillaries demonstrate guanylate cyclase synthetic activity, but the endothelial cells do not exhibit immunohistochemical staining. This suggests that physiological activity of an enzyme cannot be completely discerned through application of immunohistochemical procedures. Additionally, enzymatically detected guanylate cyclase histochemical activity was not uniformly distributed throughout the striatal neuropil. Enzyme histochemical detection of cyclic GMP phosphodiesterase demonstrates homologous cellular staining to guanylate cyclase enzymatic reactivity. The activity of the phosphodiesterase hydrolytic enzyme could be detected evenly distributed throughout the neuropil within cells 15-20 microns in diameter, analogous in cytoarchitecture to immunohistochemically visualized guanylate cyclase, cyclic GMP, and protein kinase elements. Ultrastructural examination of rat caudate-putamen demonstrates that the immunoreactivity for the components of the cyclic GMP system is predominantly distributed within the medium-spiny neuron subtype of this structure. Occasional aspiny neurons demonstrate peroxidase immunoreactivity for the cyclase, cyclic GMP, and the protein kinase, as does the luminal surface of capillary endothelial cells. The subcellular distribution of the antigenic determinants for these three elements and the hydrolytic activity of the phosphodiesterase enzyme show proximity to one another and are confined to the postsynaptic region of asymmetrical, but not symmetrical, terminal boutons. The asymmetrical terminal population of the caudate-putamen is derived from striatal afferents from the neocortex, intralaminar thalamus, and substantia nigra, and to a lesser extent the intrinsic striatal circuitry.(ABSTRACT TRUNCATED AT 400 WORDS)

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1982

Immunohistochemical localization of guanylate cyclase within neurons of rat brain.

The immunohistochemical localization of guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] has been examined in rat neocortex, caudate-putamen, and cerebellum by using specific monoclonal antibodies. Immunofluorescence could be seen within somata and proximal dendrites of neurons in the these regions. A nuclear immunofluorescence reaction to guanylate cyclase was characteristically absent. The staining pattern for guanylate cyclase was coincident with previously described localizations of cyclic GMP immunofluorescence within medium spiny neurons of the caudate-putamen and pyramidal cells of the neocortex. Cerebellar guanylate cyclase immunoreactivity was primarily confined to Purkinje cells and their primary dendrites, similar to the pattern reported for cyclic GMP-dependent protein kinase localization. Guanylate cyclase immunofluorescence was abolished when the monoclonal antibodies were exposed to purified enzyme prior to incubation of the tissue slices or when control antibody was substituted for the primary antibody. Immunohistochemical localization of cyclic AMP in these same tissues was readily distinguished from that of guanylate cyclase or cyclic GMP, showing uniform fluorescence throughout the cell bodies of neurons and glial elements.

Animals↗
PubMed1981

Ultrastructural localization of cyclic GMP and cyclic AMP in rat striatum.

The subcellular localization of cyclic GMP and cyclic AMP in the rat caudate-putamen has been studied using horseradish peroxidase immunocytochemistry. Both of the putative neurotransmitter second messengers were visualized in neurons and glial cells at light microscopic resolutions, but not all cells of either category gave detectable staining. This was confirmed at the ultrastructural level where both stained and unstained elements of the same cell type were found within the same field. A striking variation was seen in cyclic nucleotide staining intensity within individual neural and glial cells. Both of the cyclic nucleotides were detected within postsynaptic terminal boutons and within astroglial processes. Cyclic GMP postsynaptic staining was stronger than glial staining, whereas the localization pattern was reversed for cyclic AMP. The synaptic localization of cyclic AMP and cyclic GMP immunoreactivity adds support to the idea that these compounds have an influential role in synaptic function within the striatum.

Animals↗
PubMed1979

Biochemical characterization of postsynaptically localized cyclic nucleotide phosphodiesterase.

This study demonstrates the postsynaptic localization of one of the isozymes of cyclic nucleotide phosphodiesterase (PDE) activity at asymmetrical, axospinous terminals in the rat corpus striatum and neocortex. Characterization of this enzymatic activity demonstrates that the PDE form surviving aldehyde fixation for electron cytochemistry can be considered to preferentially hydrolyze cyclic 3'5'-guanosine monophosphate, and it requires calcium and a heat-stable calcium-dependent regulator protein (CDR) for full hydrolytic activity. Ion exchange chromatographic analysis of extracts of corresponding unfixed brain regions demonstrates that only one enzyme activity peak exhibits similar aldehyde resistance and calcium and regulator protein activatibility.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMedDate not supplied

Are glial cells targets of the central noradrenergic system? A review of the evidence.

It has been suggested by a number of investigators that glial cells as well as neurons are targets of the central noradrenergic system. This important hypothesis, however, has not been presented previously in a systematic and unified manner. The present review was therefore undertaken to accomplish this. The evidence supporting noradrenergic action on glia consists primarily of findings that beta-adrenoceptors, norepinephrine (NE)-stimulated cyclic AMP (cAMP) responses and glycogen are localized preferentially in glial cells and that beta-receptor density and glycogen hydrolysis are under the control of neuronally released NE. While there is some disagreement as to the extent to which beta-receptors are preferentially localized in glia, there is a consensus that most glycogen in the forebrain is localized in this cellular compartment. The presumed function of the noradrenergic action on glia appears to be the release of glucose for production of energy, the synthesis of neurotrophic factors such as nerve growth factor, and the release of substances which may affect local neurotransmission including taurine, cAMP and its metabolites. These glial responses may be intimately related to the electrophysiological actions of NE on neurons.

Animals↗