GABA Neuron Systems in Hypothalamus and the Pituitary Gland

Vincent, Steven R.; Hökfelt, Tomas; Wu, Jang‐Yen

doi:10.1159/000123288

Cited by 315 publications

(61 citation statements)

References 17 publications

(35 reference statements)

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“…GAD and GABA immunoreactive fibers are found throughout the hypothalamus, as suggested in the present study using antiserum against GAD and GABA, and in previous biochemical or immunocytochemical studies with GAD antiserum (Tappaz et al, 1982(Tappaz et al, , 1983Vincent et al, 1982). In all areas containing TH immunoreactive neurons, GAD and GABA immunoreactive axons are numerous.…”

Section: Gaba Innervation Of Hypothalamic Dopaminergic Neuronssupporting

confidence: 87%

Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses: a double pre- embedding immunocytochemical study with particulate silver and HRP

Pol¹

1986

J. Neurosci.

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Silver-intensified gold (SIG) particles were used for light-and electron-microscopic immunocytochemical localization of neuronal antigens, and the SIG method was compared with related heavy-metal methods for the purpose of dual ultrastructural localization of neurotransmitter-related antigens. SIG immunostaining was combined with peroxidase immunostaining to allow simultaneous study of differentially labeled tyrosine hydroxylase and glutamate decarboxylase immunoreactive neurons in the medial hypothalamus.A number of electron-dense markers that might be of use in double immunostaining for light and electron microscopy were examined, either with a simple nitrocellulose dot-blot method or on Formvar-coated slot grids. Of these, silver-intensified 5 nm colloidal gold was the most effective. Silver intensification of colloidal silver and of peroxidase reaction product also showed promise for combined LM and EM double-immunolabeling studies. Since the silver-intensification procedure used here intensifies both gold and peroxidase, in experiments involving double staining, the silver-intensified gold procedure should be used for the first antigen and nonintensified HRP for the second.Presumptive dopaminergic neurons containing the enzyme tyrosine hydroxylase were located throughout the hypothalamus with SIG immunostaining. In the same areas where frequent tyrosine hydroxylase immunoreactive neurons were found, many axons and bouton terminals were also found with antisera against GABA or against the GABA-synthesizing enzyme glutamate decarboxylase. Areas containing cells immunoreactive for tyrosine hydroxylase and stained with SIG and axons immunoreactive for glutamate decarboxylase and stained with peroxidase included the periventricular area (A14), the arcuate nucleus (A12), the dorsomedial hypothalamus/zona incerta area (A13), the posterior hypothalamus (All), the medial paraventricular nucleus, and dorsal to the supraoptic nucleus, in addition to the preoptic area near the third ventricle and dorsally adjacent to the anterior commissure. For comparison, the SIG procedure was also used to stain dopaminergic neurons outside the hypothalamus in the substantia nigra and ventral tegmental area. and electron microscopy. By virtue of a large silver shell formed around the colloidal gold particle and its adsorbed immunoglobulin or protein A, cross-reactivity of the first set of immunoreagents stained with particulate silver and a second set stained with peroxidase could be reduced or eliminated. To test its versatility, the SIG methodology was used to stain five other putative neurotransmitter-related antigens in the hypothalamus, including glutamate decarboxylase, somatostatin, prolactin, luteinizing hormone releasing hormone, and neurophysin in frozen sections or sections embedded in plastic, polyethylene glycol, or paraffin.In all areas examined ultrastructurally, including the arcuate nucleus (A12), the periventricular area (A14), the medial paraventricular nucleus, and the dorsomedial hypothalamus, glutamate decarboxy...

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Section: Gaba Innervation Of Hypothalamic Dopaminergic Neuronssupporting

confidence: 87%

Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses: a double pre- embedding immunocytochemical study with particulate silver and HRP

Pol¹

1986

J. Neurosci.

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“…Hypothalamic nuclei reported to contain the highest densities of GAD-immunoreactive fibers and neuropil include the following: arcuate nucleus, dorsomedial nucleus, ventral medial nucleus, perifomical region, medial and lateral parts of the mamillary body, median eminence, suprachiasmatic nucleus, and preoptic area; other related nuclei containing high densities include the fields of Fore1 and bed nucleus of the stria terminalis. After colchicine injections, GAD-immunoreactive cells became visible in the arcuate nucleus, perifomical region, and regions lateral and posterior to the medial mamillary nucleus (Vincent et al, 1982b).…”

Section: Hypothalamusmentioning

confidence: 99%

“…All have remarked on the very high density of immunoreactive fiber and neuropil staining and the difficulty of identifying immunoreactive cell somata without colchicine treatment (e.g., Perez de la Mora et al, 198 1;Vincent et al, 1982b, Tappaz et al, 1983Mugnaini and Oertel, 1985;Van den Pol, 1986). Hypothalamic nuclei reported to contain the highest densities of GAD-immunoreactive fibers and neuropil include the following: arcuate nucleus, dorsomedial nucleus, ventral medial nucleus, perifomical region, medial and lateral parts of the mamillary body, median eminence, suprachiasmatic nucleus, and preoptic area; other related nuclei containing high densities include the fields of Fore1 and bed nucleus of the stria terminalis.…”

Section: Hypothalamusmentioning

confidence: 99%

Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey

et al. 1991

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In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin- dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non- GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate. This suggests that the kinase may be differentially engaged in pre- and postsynaptic functions at certain synapses.

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“…However, recent studies indicated that suramin does not block exclusively P 2 purinoceptors; it also inhibits glutamate and GABA receptor-mediated currents (Nakazawa et al 1995), as well as the coupling of receptors to G proteins (Beindl et al 1996). Since the posterior lobe receives a well-defined GABAergic innervation from central nuclei (Oertel et al 1982, Vincent et al 1982, Buijs et al 1987 and AVP release in the pituitary is modulated by GABA-A receptors (Anderson & Mitchell 1986, Sladek & Armstrong 1987, Magnuson & Meyerson 1993, augmentation of oxytocin and AVP release by suramin could be explained by the removal of GABAergic regulatory influence. Glutamate immunoreactivity (Meeker et al 1991) and metabotropic glutamate receptor subtypes (Kiyama et al 1993) are also present in neurosecretory nerve terminals, as well as in pituicytes, and therefore glutamatergic modulation of hormone secretion has also to be considered.…”

Section: Figurementioning

confidence: 99%

Local regulation of vasopressin and oxytocin secretion by extracellular ATP in the isolated posterior lobe of the rat hypophysis

Sperlágh¹,

Mergl²,

Jurányi³

et al. 1999

Journal of Endocrinology

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It is now widely accepted that ATP functions as a signalling substance in the nervous system. The presence of P 2 receptors mediating the action of extracellular ATP in brain regions involved in hormonal regulation raises the possibility that a similar role for ATP might also exist in the neuroendocrine system. In this study, the release from the rat isolated neurohypophysis preparation of endogenous ATP, oxytocin and vasopressin (AVP) were measured simultaneously using luciferin-luciferase and RIA techniques. After 70 min preperfusion, electrical field stimulation caused a rapid increase in the amount of ATP in the effluent and the release of AVP and oxytocin also increased stimulation-dependently. Inhibition of voltage-dependent Na + channels by tetrodotoxin (1 µM) reduced the stimulation-evoked release of AVP and oxytocin; however, the evoked release of ATP remained unaffected.The effect of endogenous ATP on the hormone secretion was tested by suramin (300 µM), the P 2 receptor antagonist. Suramin significantly increased the release of AVP, and the release of oxytocin was also enhanced. ATP, when applied to the superfusing medium, decreased the release of AVP, but not that of oxytocin, and its effect was prevented by suramin.ATP (60 nmol), added to the tissues, was readily decomposed to ADP, AMP and adenosine measured by HPLC combined with ultraviolet light detection, and the kinetic parameters of the enzymes responsible for inactivation of ATP (ectoATPase and ecto5 -nucleotidase) were also determined (K m =264 2·7 and 334 165 µM and v max =6·7 1·1 and 2·54 0·24 nmol/min per preparation (n=3) for ectoATPase and ecto5 -nucleotidase respectively).Taken together, our data demonstrate the stimulationdependent release, P 2 receptor-mediated action and extracellular metabolism of endogenous ATP in the posterior lobe of the hypophysis and indicate its role, as a paracrine regulator, in the local control of hormone secretion.

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GABA Neuron Systems in Hypothalamus and the Pituitary Gland

Cited by 315 publications

References 17 publications

Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses: a double pre- embedding immunocytochemical study with particulate silver and HRP

Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses: a double pre- embedding immunocytochemical study with particulate silver and HRP

Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey

Local regulation of vasopressin and oxytocin secretion by extracellular ATP in the isolated posterior lobe of the rat hypophysis

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