Takács Gábor, Lukáts Balázs, Papp Szilárd, Szalay Csaba, Karádi Zoltán
Institute of Physiology and Neurophysiology Research Group of the Hungarian Academy of Sciences, Pécs University, Medical School, H-7624 Pécs, Szigeti Street 12, Hungary.
Neurosci Res. 2008 Oct;62(2):118-22. doi: 10.1016/j.neures.2008.06.010. Epub 2008 Jul 10.
The ventromedial hypothalamic nucleus (VMH) is a central site of action of interleukin-1beta (IL-1beta) induced feeding disturbances. This study was designed to elucidate taste-related perceptual and motivational processes potentially contributing to the anorexia and adipsia seen after bilateral IL-1beta microinjection into the VMH. A saccharin conditioned taste aversion (CTA) paradigm was tested after the central IL-1beta administration. To further investigate whether gustatory deficits are involved in development of the feeding alterations, IL-1beta induced changes of taste responsiveness were also studied in taste reactivity tests. Administration of the cytokine into the VMH did not cause the development of CTA. During taste reactivity tests, however, IL-1beta treated rats displayed significantly poorer ingestive reactions to pleasant taste stimuli than did animals of the control group. In addition, the aversive responses of IL-1beta injected rats to pleasant tastes were significantly more robust than those of control animals. The cytokine treated animals also showed stronger aversion than ingestion to hedonically positive tastes. The present findings indicate that (1) anorexigenic and adipsogenic consequences of IL-1beta microinjection into the VMH are not due to development of cytokine induced CTA; and (2) hedonic responsiveness to palatable tastes is processed by IL-1beta mediated neural mechanisms in the VMH.
腹内侧下丘脑核（VMH）是白细胞介素-1β（IL-1β）诱导进食障碍的一个主要作用部位。本研究旨在阐明味觉相关的感知和动机过程，这些过程可能导致双侧VMH内微量注射IL-1β后出现的厌食和拒饮。在中枢给予IL-1β后，测试了糖精条件性味觉厌恶（CTA）范式。为了进一步研究味觉缺陷是否参与进食改变的发展，还在味觉反应测试中研究了IL-1β诱导的味觉反应性变化。向VMH注射细胞因子并未导致CTA的形成。然而，在味觉反应测试期间，与对照组动物相比，经IL-1β处理的大鼠对愉悦味觉刺激的摄取反应明显较差。此外，注射IL-1β的大鼠对愉悦味道的厌恶反应明显比对照动物更强烈。经细胞因子处理的动物对享乐性积极味道也表现出更强的厌恶而非摄取。目前的研究结果表明：（1）向VMH微量注射IL-1β导致的厌食和拒饮后果并非由于细胞因子诱导的CTA的形成；（2）VMH中IL-1β介导的神经机制处理了对可口味道的享乐反应性。
