Present address: Rudolf Magnus Institute of Neuroscience, Utrecht, The Netherlands.
Opposite actions of hypothalamic vasopressin on circadian corticosterone rhythm in nocturnal versus diurnal species
Article first published online: 14 FEB 2008
© The Authors(2008)
European Journal of Neuroscience
Volume 27, Issue 4, pages 818–827, February 2008
How to Cite
Kalsbeek, A., Verhagen, L. A.W., Schalij, I., Foppen, E., Saboureau, M., Bothorel, B., Buijs, R. M. and Pévet, P. (2008), Opposite actions of hypothalamic vasopressin on circadian corticosterone rhythm in nocturnal versus diurnal species. European Journal of Neuroscience, 27: 818–827. doi: 10.1111/j.1460-9568.2008.06057.x
- Issue published online: 14 FEB 2008
- Article first published online: 14 FEB 2008
- Received 19 September 2007, revised 3 December 2007, accepted 19 December 2007
- Arvicanthis ansorgei;
Relatively little is known about the function of the biological clock and its efferent pathways in diurnal species, despite the fact that its major transmitters and neuronal connections are also conserved in humans. The mammalian biological clock is located in the hypothalamic suprachiasmatic nuclei (SCN). Several lines of evidence suggest that the activity cycle of the SCN itself is similar in nocturnal and diurnal mammals. Previously, we showed that, in the rat, vasopressin (VP) derived from the SCN has a strong inhibitory effect on the release of adrenal corticosterone and is an important component in the generation of a daily rhythm in plasma corticosterone concentrations. In the present study we investigated the role of VP in the control of the daily corticosterone rhythm in a diurnal rodent, i.e. Arvicanthis ansorgei. Contrary to our previous (rat) results, VP administered to the hypothalamic paraventricular nucleus in A. ansorgei had a stimulatory effect on the release of corticosterone. Moreover, both the morning and evening rise in corticosterone were blocked by the administration of a VP receptor antagonist. These results show that with regard to the circadian control of the corticosterone rhythm in diurnal and nocturnal rodents, temporal information is carried along the same pathway from the SCN to its target areas, but the response of the target area may be quite different. We propose that the reversed response to VP is due to a change in the phenotype of the target neurons that are contacted by the SCN efferents, i.e. glutamatergic instead of γ-aminobutyric acid (GABA)ergic.