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B Tinner

Publications and source records attributed to B Tinner.

43 records · Page 3Linked to original sources
PubMed1988

Pre- and postsynaptic features of the central angiotensin systems. Indications for a role of angiotensin peptides in volume transmission and for interactions with central monoamine neurons.

The transmitter receptor matches and mismatches in the angiotensin (ANG) immunoreactive (IR) neuronal systems of the rat CNS have been characterized in various regions by means of ANG II immunocytochemistry and 125I-angiotensin II receptor autoradiography. By means of in situ hybridization the distribution of angiotensinogen mRNA has been mapped out and related to the distribution of ANG IR. In some areas, high densities of ANG IR nerve terminals and ANG II receptors (e.g. paraventricular hypothalamic nucleus, locus coeruleus and nucleus tractus solitarius) or high densities of ANG II receptors alone (e.g. medial geniculate body, subthalamic nucleus and superficial layer of the superior collicle) were often associated with high levels of angiotensinogen mRNA, suggesting the existence of an extracellular formation of ANG II, mediating biological responses. These results underline a role of ANG peptides in volume transmission in addition to transmitter function. Other areas, such as nuc. n. hypoglossi, practically lacking ANG IR terminals, pericarya and receptors, also contained high levels of angiotensinogen mRNA, suggesting a different role of angiotensinogen in these areas. Evidence for presynaptic (turnover changes) and post-synaptic (receptor-receptor crosstalk) interactions with CA neuronal systems has been obtained especially in cardiovascular centers. Thus, ANG II reduces in a concentration related way the affinity of 3H-paraminoclonidine binding sites in the dorsomedial medulla without influencing the Bmax value. These results indicate the existence of intramembrane interactions between ANG II and alpha 2 adrenergic receptors. Finally paraventricular but not perifornical ANG immunoreactive nerve cells costore nuclear glucocorticoid receptor IR, suggesting that some ANG neurons may be directly regulated by glucocorticoids.

Angiotensin II↗
PubMedDate not supplied

Computer-assisted image analysis techniques allow a characterization of the compartments within the basal ganglia. Focus on functional compartments produced by d-amphetamine activation of the c-fos gene and its relationship to the glucocorticoid receptor.

A new computer-assisted image analysis procedure was developed for the analysis of striatal compartments of the rats visualized in this case by means of c-fos immunocytochemistry after morphine and/or d-amphetamine treatments. In particular it has been shown that d-amphetamine can induce an activation of the c-fos early gene in various subregions of the neostriatum and that morphine treatment can antagonize this activation. A different pattern of morphine antagonistic action could be detected at the rostral versus the caudal striatal level. In fact, at the rostral level the morphine antagonistic action was very marked only in the dorsomedial striatum, while at the caudal level the morphine antagonistic action was marked in all subregions. The developed computer-assisted procedure can detect differences in the pattern of distribution of profiles present in a certain neuroanatomical area. Therefore, this procedure may represent a powerful tool to study integrative functional compartments in the neostriatum. In the present study high level integrative compartments appear to be created by D1/mu-opiate receptor interactions especially within the classical patch system.

Animals↗
PubMedDate not supplied

Distribution of dopamine-immunoreactive neurons and their relationships to transmitter and hypothalamic hormone-immunoreactive neuronal systems in the rat mediobasal hypothalamus. A morphometric and microdensitometric analysis.

A morphometric and microdensitometric characterization of the dopamine neurons of the mediobasal hypothalamus and their relationships with several other chemically identified systems, including putative tyrosine hydroxylase-positive/dopamine-negative neurons, was carried out after visualization of dopamine content by both immunocytochemistry and the Falck-Hillarp technique. Quantitative assessment of co-existence demonstrated that more than 95% of dopamine-immunoreactive neurons also contained tyrosine hydroxylase immunoreactivity and more than 90% of growth hormone-releasing factor-immunoreactive neurons also contained tyrosine hydroxylase immunoreactivity. Morphometric and densitometric analysis of dopamine, tyrosine hydroxylase and growth hormone-releasing factor-immunoreactive neurons in the arcuate nucleus showed that dopamine/tyrosine hydroxylase-containing and growth hormone-releasing factor/tyrosine hydroxylase-containing neuronal populations are two largely segregated cell groups with specific localization in the arcuate region, rostrocaudal extension and tyrosine hydroxylase-immunoreactivity content. Morphometric characteristics of dopamine-immunoreactive neurons were shown to be equivalent to those of catecholamine fluorescent cell bodies in the arcuate region. In addition, a cell group lacking detectable catecholamine fluorescence in normal animals but accumulating L-DOPA after peripheral loading was identified and characterized from a morphometric standpoint in the ventral premammillary nucleus. Quantitative analysis of nerve terminal co-distribution in the median eminence revealed significant correlations between dopamine and other transmitter or neurohormone systems, such as gamma-aminobutyric acid, galanin, luteinizing hormone-releasing hormone, in specific subregions of the palissade zone. These data point to discrete subregions of the median eminence, which have been called 'medianosomes', as main sites of interactions between transmitter-identified nerve terminal systems in the control of hypothalamic hormone release.

Animals↗
PubMedDate not supplied

The distribution of serotonin in the brain of Apteronotus leptorhynchus: an immunohistochemical study.

The immunohistochemical distribution of serotonin (5-HT) cells, fiber tracts and terminal fields was mapped in the brain of the gymnotiform electric fish. Two major types of 5-HT cells were found: the small paraventricular organ (PVO) cells of the diencephalon, and the large raphe cells of the brain stem. Six diencephalic nuclei were identified: the nucleus preopticus periventricularis, anterior division, nucleus posterioris periventricularis, nucleus recessus lateralis medial subdivisions 1, 2 and 3, and nucleus recessus posterioris. In the brainstem, raphe centralis, between the arms of the medial longitudinal fasciculus (MLF), the raphe medialis, lateral to MLF, and the diffuse raphe posterioris, were described. Five 5-HT fiber tracts were identified. The tract rising from PVOs projected rostrally through the medial forebrain bundle (MFB). The central tegmental bundle arising from the raphe centralis-medialis complex projected rostrally and also joined the MFB. The lateral tegmental tract, the ventrolateral and the subtrigeminal tracts arose from brain stem raphe groups and innervated the brainstem nuclei. The densest 5-HT innervation occurred in the hypothalamus in the neuropil of the PVOs and in the brainstem in the interpeduncular nucleus, cranial nerve nuclei V motor, V tractus spinalis, VII, X sensory and lateral inferior olive. Electrosensory nuclei including the electrosensory lateral line lobe, the nucleus praeminentialis, dorsal torus semicircularis, optic tectum, nucleus electrosensorius and prepacemaker nucleus received light to medium 5-HT innervation. Serotonergic terminal fields appeared to be conserved across phyla with additional innervation evident in specialized sensory regions such as the electrosensory nuclei of gymnotiform and mormyriform fish.

Animals↗