Engelmann Mario, Ebner Karl, Landgraf Rainer, Wotjak Carsten T
Otto-von-Guericke-Universität Magdeburg, Institut für Medizinische Neurobiologie, Leipziger Str. 44, D-39120 Magdeburg, Germany.
Horm Behav. 2006 Sep;50(3):496-501. doi: 10.1016/j.yhbeh.2006.04.009. Epub 2006 Jul 27.
Adult male Wistar rats were trained in the Morris water maze (MWM) on 3 consecutive days to find a visible platform. Concomitantly, microdialysis samples from the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei were collected in order to monitor local release of the neuropeptides vasopressin (AVP) and oxytocin (OXT), respectively, during controllable swim stress. Additionally, a separate set of animals was equipped with chronic jugular venous catheters to collect blood samples for analyzing plasma concentrations of corticotropin (ACTH) and corticosterone during training in the MWM. As measured by microdialysis, swimming in the MWM caused a significantly increased release of AVP within the PVN and of OXT within the SON on each of the 3 test sessions. In contrast to OXT in the SON, basal AVP concentrations in the PVN tended to rise from day to day. Plasma ACTH and corticosterone were found to be similarly elevated in response to MWM exposure on each of the test sessions. Taken together, these data demonstrate that testing in the MWM is not only associated with a significant activation of the hypothalamo-pituitary-adrenal axis but also with an intrahypothalamic release of AVP and OXT. If compared with findings using repeated forced swimming as an uncontrollable stressor (Wotjak, C.T., Ganster, J., Kohl, G., Holsboer, F., Landgraf, R., Engelmann, M., 1998. Dissociated central and peripheral release of vasopressin, but not oxytocin, in response to repeated swim stress: new insights into the secretory capacities of peptidergic neurons. Neuroscience 85, 1209-1222), the present results suggest that (1) similarities in the release profiles of AVP in the PVN and plasma hormone levels are fairly independent from the controllability of the stressor and seem, thus, to primarily relate to the physical demands of the task, whereas (2) the different intra-SON OXT release profiles might be linked to the controllability of the stressor.
成年雄性Wistar大鼠连续3天在莫里斯水迷宫（MWM）中接受训练以寻找可见平台。同时，收集来自下丘脑室旁核（PVN）和视上核（SON）的微透析样本，以便在可控游泳应激期间分别监测神经肽血管加压素（AVP）和催产素（OXT）的局部释放。此外，另一组动物配备慢性颈静脉导管，用于在MWM训练期间采集血样，以分析促肾上腺皮质激素（ACTH）和皮质酮的血浆浓度。通过微透析测量，在MWM中游泳导致在3个测试阶段的每一天，PVN内AVP的释放以及SON内OXT的释放均显著增加。与SON中的OXT不同，PVN中的基础AVP浓度有逐日上升的趋势。在每个测试阶段，发现血浆ACTH和皮质酮因MWM暴露而同样升高。综上所述，这些数据表明，在MWM中进行测试不仅与下丘脑 - 垂体 - 肾上腺轴的显著激活有关，还与下丘脑内AVP和OXT的释放有关。如果与使用重复强迫游泳作为不可控应激源的研究结果（Wotjak，C.T.，Ganster，J.，Kohl，G.，Holsboer，F.，Landgraf，R.，Engelmann，M.，1998. 重复游泳应激后血管加压素而非催产素的中枢和外周释放解离：肽能神经元分泌能力的新见解。神经科学85，1209 - 1222）相比，目前的结果表明：（1）PVN中AVP释放模式与血浆激素水平的相似性相当独立于应激源的可控性，因此似乎主要与任务的体力需求有关，而（2）SON内不同的OXT释放模式可能与应激源的可控性有关。
