The dorsal raphe nucleus (DRN) is a brainstem nucleus involved in the pathophysiology of the depression, through its serotoninergic innervation. Furthermore, depressive symptoms in patients are also associated with some memory and sleep complaints. Anatomical evidence confirmed the presence of projections from the lateral hypothalamus to serotonergic neurons of the dorsal raphe nucleus (DRN). These projection fibers release orexin neuropeptides which play roles in the spatial memory. Both of the orexinergic receptors are widely distributed in dorsal raphe nucleus. Therefore, the present work was aimed to assess the probable roles of orexin 1 and 2 receptors using an orexin 1 receptor antagonist, SB-334867-A, and an orexin 2 receptor antagonist, TCS-OX2–29 in the DRN on the retrieval, and consolidation phases of spatial reference memory in the Morris water maze (MWM) task. The results demonstrated that blocking orexin 1 receptors in the DRN impairs the process of memory consolidation in the spatial MWM via increasing in the time of the escape latency of the probe day. Blocking these receptors did not affect the retrieval phase of MWM learning. Furthermore, blocking of the orexin 2 receptors in this area did not affect neither consolidation nor retrieval phases of the memory. In conclusion, orexin 1 receptors in the DRN play major roles in the consolidation of the spatial reference memory in rats.

背沟核（DRN）是通过其5-羟色胺能神经支配参与抑郁症病理生理的脑干核。此外，患者的抑郁症状还与一些记忆力和睡眠障碍有关。解剖学证据证实，存在从下丘脑外侧到背缝核（DRN）的血清素能神经元的投射。这些投射纤维释放食欲素神经肽，它们在空间记忆中发挥作用。两种食欲素能受体广泛分布在背缝核中。因此，目前的工作旨在评估在检索过程中使用orexin 1受体拮抗剂SB-334867-A和orexin 2受体拮抗剂TCS-OX2-29在DRN中评估orexin 1和2受体的可能作用，莫里斯水迷宫（MWM）任务中的空间参考记忆的合并和合并阶段。结果表明，在DRN中阻断orexin 1受体会通过增加探测日逃避潜伏时间来损害空间MWM中的记忆巩固过程。阻断这些受体不会影响MWM学习的检索阶段。此外，在该区域中对orexin 2受体的阻断既不影响记忆的巩固也不恢复阶段。总之，DRN中的orexin 1受体在大鼠空间参考记忆的巩固中起主要作用。阻断这些受体不会影响MWM学习的检索阶段。此外，在该区域中对orexin 2受体的阻断既不影响记忆的巩固也不恢复阶段。总之，DRN中的orexin 1受体在大鼠空间参考记忆的巩固中起主要作用。阻断这些受体不会影响MWM学习的检索阶段。此外，在该区域中对orexin 2受体的阻断既不影响记忆的巩固也不恢复阶段。总之，DRN中的orexin 1受体在大鼠空间参考记忆的巩固中起主要作用。