Cellular mechanisms underlying differentiation of AVP expression

Two fundamentally different sets of processes could cause differences in AVP cell number processes such as cell birth, cell death, or cell migration, or processes that influence the pheno-type of existing cells. Differential cell birth and migration are unlikely, because AVP cells are born at least a week before hormones trigger their sexual differentiation (Wang et al., 1993 Al-Shamma and De Vries, 1996). Differential cell death can probably be ruled out as well, because the sex difference...

P2x7

AmRNA by RT-PCR in SON punches (Shibuya et al., 1999) *mRNA for P2X6 was detected (Shibuya et al., 1999) however, in expression systems, ATP induces only very small or undetectable currents via these subtypes. mRNA expression was most prominent for P2X3, 4 and 7. Ca imaging in isolated SON neurons (Shibuya et al., 1999). cCa + + imaging of isolated nerve terminals from neural lobe (NL Troadec et al., 1998). Intracellular electrophysiological recordings from HNS explants (Hiruma and Bourque,...

Oxytocin and appetite

Gareth Leng*, Tatsushi Onaka, Celine Caquineau, Nancy Sabatier, Vicky A. Tobin Centre for Integrative Physiology, The University of Edinburgh, Edinburgh UK and Jichi Medical University, Abstract Oxytocin has potent central effects on feeding behaviour, as well as on social and sexual behaviours, and one likely substrate for its anorectic effect is the ventromedial nucleus of the hypothalamus. This nucleus expresses a high density of oxytocin receptors, but contains very few oxytocin-containing...

Oxytocin receptor signalling

Dominic Devost1'**, Paulina Wrzal1 and Hans H. Zingg1'2'3'* 1 Department of Pharmacology, McGill University, Montreal, Quebec, Canada 2Department of Medicine, McGill University, Montreal, Quebec, Canada 3Department of Obstetrics & Gynecology, McGill University, Montreal, Quebec, Canada Abstract The great diversity of the expression sites and proposed function of the oxytocin (OXT) receptor (OXTR) is paralleled by a diversity of its signalling pathways, many of which have still remained...

Pp

Regulation of the SON neuron activity by neurotransmitters modulators. The sketch summarizes the possible actors involved in the mechanisms controlling the excitability of neurons in the SON. It is of interest to note that many neurotransmitters modulators (NT) are somehow involved in neuronal (SON) activity regulation in some way or the other, only a few NT regulate the release of AVP OXT at the level of neurohypophysis (PP). They induce different parallel signalling cascades that also...

Gpcr Oxt Oxtr

Onaka (Jichi Medical School, Tochigi, Japan), T. Kimura (Osaka University, Osaka Japan), K. Itoi (Tohoku University, Miyagi, Japan) for collaborations, technical assistance, discussion and encouragement. This work was supported in part by a Grant-in-Aid for Scientific Research (B) from the Ministry of Education, Culture, Sports, Science and Technology of Japan (14360046) and by the Sankyo Foundation of Life Science. M.Y. was supported by a Japan Society for the Promotion of Science...

Behavioural studies using temporal and spatial inactivation of the oxytocin receptor

Caldwell2, Abbe H. Macbeth1 and W. Scott Young III1'* 1 Section on Neural Gene Expression, National Institute of Mental Health, National Institutes of Health, DHHS, Bethesda, MD, USA 2Department of Biological Sciences, Kent State University, Kent, OH, USA Abstract Oxytocin (Oxt), synthesized in magnocellular neurons of the paraventricular (PVN) and supraoptic (SON) hypothalamic nuclei for transport to and release from the posterior pituitary, is released during...

Regulation of vasopressin release by coreleased neurotransmitters mechanisms of purinergic and adrenergic synergism

Department of Physiology and Biophysics, University of Colorado at Denver and Health Sciences Center, Abstract Arginine vasopressin (AVP) neurons of the hypothalamo-neurohypophseal system (HNS) are innervated by numerous afferent pathways carrying information about two physiologically important parameters blood volume pressure and osmolality. These pathways use a variety of neurotransmitters neuropeptides. In order to understand normal and pathological regulation of VP secretion, the mechanisms...

Lessons from spotted hyenas and prairie voles

Spotted hyenas show unusual sexual differentiation. For example, female hyenas develop a phallus as large as that of a male (Matthews, 1939 Watson, 1877). They also show a reversal of typical sex difference in behaviour, with female hyenas being socially dominant and more aggressive than males (Matthews, 1939 Hamilton et al., 1986). Although the lack of sexual differentiation in peripheral tissue is not well understood, unusually high androstenedione levels in females during development and in...

Interactions between dopamine and oxytocin in the control of sexual behaviour

Douglas Centre for Integrative Physiology, SBMS, University of Edinburgh, Hugh Robson Building, George Square, Abstract Dopamine and oxytocin are two key neuromodulators involved in reproductive behaviours, such as mating and maternal care. Much evidence underlies their separate roles in such behaviours, but particularly in sexual behaviour. It is generally believed that central dopaminergic and oxytocinergic systems work together to regulate the expression...

Opposite effects of oxytocin and vasopressin on the emotional expression of the fear response

1 Centre for Psychiatric Neurosciences, Department of Psychiatry, University Hospital Center Lausanne (CHUV), Prilly-Lausanne, Switzerland 2Centre for Psychiatric Neurosciences, Department of Psychiatry, University Hospital Center Lausanne (CHUV), Prilly-Lausanne, Switzerland and Department of Physiology, University of Lausanne, Lausanne, Switzerland Abstract Oxytocin and vasopressin are two neuropeptides that have been extensively studied for their systemic and physiological roles. Studies in...

Info

Expression of dopamine D2, D3 and D4 receptors and oxytocin (OXT) in the MPN, SON and PVN of untreated sexually experienced male rats (dopamine receptor staining is shown in green and OXT peptide staining is shown in red). The D2, D3 and D4 receptors were shown separately to co-localize with OXT in the MPN, SON and PVN. All D2-like receptors were distributed in the cell membrane and the cytosol of OXT neurons. Additionally, D3 receptors were found to be expressed on the dendritic...

Brain during delivery

Rustem Khazipov*, Roman Tyzio and Yehezkel Ben-Ari INMED-INSERM U29, Universit de la M diterran e, Marseille, France Abstract Oxytocin (OXT) exerts multiple effects in the adult central nervous system. However, little is known about the effects of OXT on foetal neurons during delivery, at the time when a surge of OXT occurs. In a recent study, the effects of OXT on gamma-aminobutyric acid (GABA) signalling have been reported in foetal and newborn rats. In the immature rat hippocampal and...