Schneider T, Thalau HP, Semm P, Wiltschko W
J Exp Biol. 1994 Sep;194(1):255-62. doi: 10.1242/jeb.194.1.255.
After pinealectomy, young pied flycatchers tested in the geomagnetic field have been found to be disoriented. In order to examine the possible role of the pineal hormone melatonin, handraised flycatchers were pinealectomized (PX) at the age of 8 weeks. From the day of operation onward, the PXMEL group received 100 µg of melatonin every evening 1 h before darkness, the PXSOL group was injected with the solvent only, and the PX group was untreated. Unoperated birds served as controls. During the following autumn migration, the birds were tested for directional preference in the local geomagnetic field, in the absence of visual cues. The controls were oriented in the species-specific southwesterly direction; pinealectomized birds without additional melatonin (PXSOL, PX) did not show directional preferences. The PXMEL birds that had received daily injections of melatonin also showed significant southwesterly tendencies; their orientation did not differ from that of the controls. This indicates that melatonin is involved in migratory orientation, either in the processes of expressing the genetically encoded information on the migratory course as a direction with respect to the geomagnetic field or in the time programme controlling the specific migratory direction at a given time.
松果体切除后，在地磁场中接受测试的年轻斑姬鹟被发现迷失了方向。为了研究松果体激素褪黑素可能发挥的作用，对人工饲养的斑姬鹟在8周龄时进行了松果体切除（PX）。从手术当天起，PXMEL组在每天傍晚天黑前1小时接受100微克褪黑素，PXSOL组仅注射溶剂，PX组不做处理。未做手术的鸟类作为对照。在接下来的秋季迁徙期间，在没有视觉线索的情况下，对这些鸟类进行地磁场中方向偏好测试。对照组朝着特定物种的西南方向定向；没有额外褪黑素的松果体切除鸟类（PXSOL、PX）没有表现出方向偏好。每天注射褪黑素的PXMEL组鸟类也表现出显著的西南方向倾向；它们的定向与对照组没有差异。这表明褪黑素参与了迁徙定向，要么参与了将关于迁徙路线的遗传编码信息表达为相对于地磁场的方向的过程，要么参与了控制特定时间特定迁徙方向的时间程序。
