Oxytocin-containing neurons in the hypothalamic parvicellular paraventricular nucleus of the jerboa: no plasticity related to acute immobilization.
OBJECTIVE
The presence of oxytocin (OT) and its putative participation to the phenotypic plasticity of CRH neurones in the stressed jerboa was investigated. We analysed by immunocytochemistry the OT expression within the hypothalamic parvicellular paraventricular nucleus (pPVN) of male jerboas submitted to an acute immobilization (30 min).


RESULTS
OT presence was clearly demonstrated in the pPVN of the jerboa and no significant difference in the number of OT immunolabeled cells was observed whatever the experimental conditions. Interestingly, CRH-immunoreactive neurons coexpressed OT within cell bodies and terminals in a similar way both in control and stressed animals. The level of coexpression was regionally heterogeneous and was not sensitive to the stress immobilization.


CONCLUSIONS
The present data reveal for the first time the occurrence of OT in hypothalamic pPVN neurons of the jerboa. Moreover, this OT expression level does not change upon an acute immobilization stress. These new data, coupled together with our previous work in the jerboa, incontestably establish a clear dichotomy between a stress-responsive CRH/CCK system and a stress non-responsive OT/VP system in the pPVN.
Barakat
Youssef
Y
Laboratory of Neuroendocrinology and Nutritional and Climatic Environment, University Sidi Mohammed Ben Abdellah, Faculty of Sciences Dhar El Mehraz, Fez, Marocco.
Pape
Jean-Remi
JR
Chaigniau
Michel
M
El Ouezzani
Seloua
S
Alaoui
Abdelilah
A
Barakat
Latifa
L
Magoul
Rabia
R