Publications by authors named "Voorhuis T"

Unlabelled: The distribution of vasotocin (VT)-immunoreactive cells and fibers in the zebra finch brain was studied with immunocytochemical techniques. A large number of VT-immunoreactive cells was found in the nucleus preopticus anterior and nucleus paraventricularis. In the lateral parts of the hypothalamus diffusely organized VT-immunoreactive cells were present.

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Groups of juvenile and 1-year-old male canaries were treated briefly with the vasotocin (VT) analog desGly(NH2)9d(CH2)5-[Tyr(Me)2,Thr4, Orn8]VT (dGVTA) during four time intervals between September and February. The canaries received subcutaneously testosterone-containing silastic implants at the start of the VT analog treatment to assure that despite age and season differences the birds would all have comparable plasma levels of testosterone. The VT analog was administered subcutaneously (0.

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Using immunocytochemistry the central VT system of the canary was examined during ontogeny and throughout the season. At 4 weeks of age no VT-immunoreactive staining in the bed nucleus of the stria terminalis and lateral septum was present, but VT-containing cells and fibers were clearly visible in the nucleus paraventricularis of the hypothalamus. At 13 weeks of age a weak VT immunoreactivity appeared in the bed nucleus of the stria terminalis and lateral septum.

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Abstract The aim of this study was to characterize neurohypophyseal hormone receptors in the brain of the canary (Serinus canarius) by using autoradiographical and biochemical procedures with a radioiodinated vasotocin analogue, [(125) l]d(CH(2))(5)[Tyr(Me)(2), Thr(4), Orn(8), Tyr-NH(2) (9)]vasotocin ([(125) I]-OTA). This synthetic analogue was used previously to identify a population of oxytocin-like receptors in the rat brain that have high affinity for vasotocin. In vitro autoradiography revealed high affinity binding sites for [(125) I]-OTA in the canary brain in the archistriatum surrounding the nucleus robustus archistriatalis.

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Diurnal changes in the expression of the vasopressin (VP) and oxytocin (OT) genes in the supraoptic (SON), paraventricular (PVN) and suprachiasmatic nuclei (SCN) of the rat were investigated by dot-blot and in situ hybridization of the VP and OT mRNAs. A significant diurnal variation in VP mRNA level was measured in the SCN, with highest levels around 17.00 h and lowest levels around midnight.

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[3H]Vasopressin was used to detect and to quantitate specific binding sites with in vitro receptor autoradiography in the canary brain. A discrete regional distribution of [3H]vasopressin-labelled binding sites was observed. A high density of specific binding sites was present in the medial posterior hypothalamic nucleus, the superficial layer of the optic tectum, the area ventralis of Tsai (AVT), the nucleus pretectalis, the habenula, the nucleus of Darkschewitch and the nucleus interstitialis.

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A sexual difference in vasotocin (VT) immunoreactivity was observed in the canary brain. The male canary displays denser VT innervation of the lateral septum and more VT-immunoreactive cells are visible in the dorsal diencephalon than in the female canary. This sex difference is the consequence of gonadal influences.

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The distribution of vasotocin (VT)-immunoreactive neuronal perikarya and fibers in the canary (Serinus canaria) was investigated with immunohistological techniques. The results suggest that most VT-stained cell bodies are located in three diencephalic regions. First, a large number of densely packed neurons are found in the paraventricular nucleus (PVN) and the anterior preoptic nucleus.

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Oxytocin mRNA was detected in the rat hypothalamus by in situ hybridization to a single stranded 35S-labelled DNA probe and the distribution of oxytocin mRNA-containing cell groups was studied at the macroscopic level. Specificity of hybridization was confirmed by comparison to vasopressin mRNA hybridization in parallel tissue sections. Cell groups containing oxytocin mRNA were confined to a set of hypothalamic cell groups, i.

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Due to a genetic defect the homozygous Brattleboro rat is unable to synthesize vasopressin gene products but still transcribes a mutant vasopressin mRNA from the gene. To study the influence of vasopressin gene products on the development of vasopressin gene expression, vasopressin mRNA levels of the supraoptic and paraventricular nucleus were measured at fetal day 20, postnatal day 1, 15 and 30 in the Wistar rat and in the heterozygous and homozygous Brattleboro rat by Northern blot analysis and in situ hybridization. In the homozygous Brattleboro rat of fetal day 20 and postnatal day 1, no or minute amounts of vasopressin mRNA were detectable but vasopressin mRNA was readily detectable at postnatal day 15 and 30.

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A discrete neuro-anatomical pattern of binding sites was observed for a principal metabolite of arginine-vasopressin (VP4-9) after incubation of tissue sections with [35S]VP4-9 and autoradiography. [35S]VP4-9-labeled binding sites were highly concentrated in the pineal gland, the nucleus tractus solitarii (nts), the arcuate nucleus region (an) and the organum vasculosum lamina terminalis (ovlt). The distribution of these sites is distinctly different from the putative VP and oxytocin receptor systems in rat brain.

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Binding sites for arginine-vasopressin (AVP) and oxytocin (OT) were detected in neuroanatomically defined regions of rat brain by using in vitro incubation of 32 micron brain sections with the tritium-labelled ligands and autoradiography with LKB Ultrofilm. Sites were quantified by computerized densitometry of the film images. The highest amount of [3H]AVP-labelled binding sites were observed in the ventral subiculum of the hippocampus, central amygdala nucleus, lateral septum, olfactory nucleus and nucleus tractus solitarii, while the dentate gyrus contained a large amount of low affinity binding.

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Specific binding sites for arginine-vasopressin (AVP) were detected in rat brain after incubation of tissue sections with [3H]AVP. AVP and two selective AVP antagonists are capable of displacing [3H]AVP with an IC50 in the 10(-8)-10(-7) molar range, while oxytocin and ACTH4-10 were much less effective. The neuroanatomical distribution of [3H]AVP-labeled sites was studied with autoradiography utilizing tritium-sensitive LKB film and computerized densitometry for quantitative analyses of the film images.

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The localization of transcortin (CBG) in pituitary cells of the rat was investigated using the peroxydase-antiperoxydase (PAP) technique. A rabbit antiserum against purified rat plasma transcortin was used as the primary antiserum. Transcortin-like (CBG-like) immunoreactive products were found in the cytoplasma of certain cells in the anterior pituitary, but not in the intermediate lobe and weakly in the posterior pituitary.

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The effect of unilateral removal of the dorsal hippocampus and of glucocorticoid administration was measured on the activity of ornithine decarboxylase (ODC) in the remaining contralateral hippocampus lobe. Unilateral hippocampectomy (Hx) resulted in a rapid rise of ODC activity in the contralateral lobe. The effect on ODC was maximal at 6 h after surgery and lasted two days.

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