Van Erp A M, Kruk M R, Semple D M, Verbeet D W
Ethopharmacology Group, Sylvius Laboratory, Leiden, The Netherlands.
Brain Res. 1993 Apr 2;607(1-2):108-12. doi: 10.1016/0006-8993(93)91494-d.
The present study was designed to discriminate between factors that initiate and/or prolong self-grooming. The study of factors initiating the grooming response is complicated by the fact that rats may groom already as a consequence of the injection procedure, due to release of endogenous substances after needle insertion or just handling of the animal. Therefore we used an infusion technique that allowed the rats to settle down quietly after they had been connected to an infusion pump, before the actual infusion of the peptide took place. In a previous report, we showed that direct injections of ACTH1-24 and alpha-melanocyte-stimulating hormone (alpha-MSH) into the paraventricular nucleus of the hypothalamus (PVH) prolong self-grooming caused by the injection procedure. Whether these peptides can also initiate grooming, however, is not yet clear. In this report, we compare the effects of alpha-MSH and oxytocin after infusion into the PVH in resting animals. Oxytocin is abundantly present in the PVH and is known to be involved in the regulation of grooming behavior. Slow infusions of oxytocin (0.1 microgram) do initiate grooming, but alpha-MSH (0.1 microgram) is without any behavioral effect. This suggests that oxytocin in the PVH is involved in the initiation of self-grooming, whereas alpha-MSH and probably ACTH do maintain grooming initiated otherwise, either by mechanical activation of the PVH and/or by the handling procedures. Infusion of substances in resting animals apparently is a way to avoid interactions between ongoing overt behavior and peptide-induced effects.
本研究旨在区分引发和/或延长自我梳理行为的因素。由于在注射过程中，大鼠可能因针刺后内源性物质的释放或仅仅是对动物的处理而已经开始梳理毛发，这使得对引发梳理反应因素的研究变得复杂。因此，我们采用了一种灌注技术，使大鼠在连接到灌注泵后能够安静下来，然后再实际灌注肽。在之前的一份报告中，我们表明，向下丘脑室旁核（PVH）直接注射促肾上腺皮质激素1 - 24（ACTH1 - 24）和α-黑素细胞刺激素（α-MSH）会延长由注射程序引起的自我梳理行为。然而，这些肽是否也能引发梳理行为尚不清楚。在本报告中，我们比较了在静息动物中向PVH灌注α-MSH和催产素后的效果。催产素大量存在于PVH中，并且已知参与梳理行为的调节。缓慢灌注催产素（0.1微克）确实会引发梳理行为，但α-MSH（0.1微克）没有任何行为效应。这表明PVH中的催产素参与了自我梳理行为的引发，而α-MSH以及可能的ACTH则维持由其他方式引发的梳理行为，这些方式包括对PVH的机械激活和/或处理程序。向静息动物灌注物质显然是一种避免正在进行的明显行为与肽诱导效应之间相互作用的方法。
