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Radboud Universiteit Nijmegen, 11 november 2014, Promotores : Vissers, K.C.P., Roubos, E.W. Co-promotores : Zundert, J. van, Kozicz, L.T., Contains fulltext : 131646.pdf (publisher's version ) (Open Access)

Radboud Universiteit Nijmegen, 26 oktober 2012, Promotores : Roubos, E.W., Peeters, B.W.M.M. Co-promotor : Kozicz, L.T., Contains fulltext : 98578.pdf (publisher's version ) (Open Access)

Radboud Universiteit Nijmegen, 12 december 2011, Promotor : Roubos, E.W. Co-promotor : Kozicz, L.T., Contains fulltext : 91338.pdf (publisher's version ) (Open Access), The aim of this thesis research was to test our hypothesis that the non-preganglionic Edinger-Westphal nucleus (npEW) serves as an integrating center linking energy metabolism with stress adaptation. We have shown indeed that the npEW receives information about stress stimuli and the peripheral metabolic state. Moreover, it appears that not only the npEW as a whole responds to this information by changing its activity, but also that this reaction is a result of the differential reactions of the various neuropeptides expressed in this nucleus. Our results extend knowledge of the energy-dependent regulation of the stress adaptation response and, hopefully, will contribute to broadening insight into the etiology of stress-induced anxiety, depression and eating disorders, as well as may stimulate research to identify novel treatments to combat these disorders. In this respect, future studies on the mechanisms by which energy balance and leptin participate in the regulation of the npEW-Ucn1/CART system will be of particular interest.

RU Radboud Universiteit Nijmegen, 2 november 2006, Promotores : Roubos, E.W., Barendregt, H.P. Co-promotor : Veening, J.G., Contains fulltext : 29821.pdf (publisher's version ) (Open Access)

RU Radboud Universiteit Nijmegen, 4 juli 2006, Promotor : Roubos, E.W. Co-promotor : Scheenen, W.J.J.M., Contains fulltext : 27463.pdf (publisher's version ) (Open Access), To investigate the way by which multiple incoming neurochemical messengers control second messenger systems to evoke an unambiguous neuronal output, melanotrope neuroendocrine cells in the pars intermedia of the pituitary gland of the South African clawed toad Xenopus laevis were studied. Researches in this thesis reveal: 1) Black-adapted melanotropes express all classes of high-voltage activated (HVA) Ca2+ channels, namely the L, N, P/Q and R types, but no low-voltage-activated (LVA) Ca2+ channels. 2) The N-type and R-type channels are involved in the generation of spontaneous intracellular Ca2+ oscillations. 3) The three GiPCRs inhibit the R-type Ca2+ currents through G / subunits. 4) Activation of the DA-D2 and the NPY-Y1 receptor inhibit the N-type Ca2+ current through another, as yet unidentified mechanism. These receptors inhibit this calcium current with similar strength as they inhibit MSH secretion. 5) Synergy between the two stimulatory neuropeptides TRH and sauvagine reverses D2-receptor-induced inhibition of spontaneous Ca2+ oscillations and action current firing, whereas the individual stimulatory peptides are ineffective. The combination of TRH and sauvagine cannot reverse the D2-receptor-induced inhibition of the R- and N-type Ca2+ currents, and as a result also do not reverse the inhibition of hormone secretion. The results also indicate that the Xenopus melanotrope can generate Ca2+ oscillations that are independent of Ca2+ influx through R- and N-type Ca2+ channels. 6) Ca2+-dependent regulation of Ca2+ currents is correlated with adaptation to background light intensity: in melanotropes from white-adapted toads, Ca2+-dependent regulation of L-type Ca2+ channels is more dominant than in black-adapted melanotropes. 7) In contrast to black-adapted melanotropes, white-adapted melanotropes express LVA Ca2+ channels. In conclusion, the experiments described in this thesis have revealed some important features of the melanotrope cell and have provided new

RU Radboud Universiteit Nijmegen, 17 maart 2004, Promotor : Roubos, E.W. Co-promotores : Scheenen, W.J.J.M., Luijtelaar, E.L.J.M. van, Item does not contain fulltext

RU Radboud Universiteit Nijmegen, 17 maart 2004, Promotor : Roubos, E.W. Co-promotores : Scheenen, W.J.J.M., Luijtelaar, E.L.J.M. van, Item does not contain fulltext

RU Radboud Universiteit Nijmegen, 17 maart 2004, Promotor : Roubos, E.W. Co-promotores : Scheenen, W.J.J.M., Luijtelaar, E.L.J.M. van, Item does not contain fulltext