DST-IRHPA Center for Excellence in Biological Rhythm Research, Department of Zoology, University of Delhi, Delhi, 110 007, India.
Eur J Neurosci. 2011 Jul;34(1):99-109. doi: 10.1111/j.1460-9568.2011.07737.x. Epub 2011 Jun 16.
Olfactory and visual sensory mechanisms seem to play a critical role in migratory orientation and navigation. How these two mechanisms are functionally linked with other migratory processes is unknown. We investigated this, in relation to the profound behavioural shift that occurs during migration in the night-migratory blackheaded bunting (Emberiza melanocephala). Photosensitive unstimulated birds singly housed in activity cages were subjected to long days (LD 16/8). The activity of each bird was continuously monitored. Daily activity pattern defined the nonmigratory phase (no nocturnal activity) and migratory phase (intense nocturnal activity, Zugunruhe). Body mass and testis size were measured at the beginning and end of the experiment. Long days induced the migratory phenotype (body fattening and Zugunruhe) and testis maturation. The c-fos (Fos) immunoreactivity, as marker of the neural activity of the olfactory and visual subsystems, was measured at midday (8 h after lights-on) and midnight (4 h after lights-off) after the first seven long days (nonmigratory phase) and after seven nights of the Zugunruhe (migratory phase). In the nonmigratory phase, Fos-like immunoreactive (Fos-lir) cells in the olfactory and visual subsystems were high in the day and low at night. In the migratory phase, this was reversed; Fos-lir cells were high at night and low in the day. The phase inversion of neural activity in the olfactory and visual systems in parallel with the behavioral shift suggests a functional coupling between the systems governing migratory flight (expressed as Zugunruhe) and migratory orientation and navigation.
嗅觉和视觉感觉机制似乎在迁徙定向和导航中起着关键作用。这两种机制如何与其他迁徙过程在功能上联系起来尚不清楚。我们研究了这一点，涉及到夜行黑眉朱雀（Emberiza melanocephala）在迁徙期间发生的深刻行为转变。在活动笼中单只饲养对光照敏感的未受刺激的鸟类，并给予长光照（LD 16/8）。每只鸟的活动都被连续监测。每日活动模式定义了非迁徙相（无夜间活动）和迁徙相（强烈的夜间活动，迁徙躁动）。在实验开始和结束时测量体重和睾丸大小。长光照诱导迁徙表型（体脂增加和迁徙躁动）和睾丸成熟。c-fos（Fos）免疫反应性作为嗅觉和视觉子系统神经活动的标志物，在第一个长光照期的第 7 天（非迁徙相）和迁徙躁动的第 7 个夜晚后（迁徙相）的中午（光照后 8 小时）和午夜（光照后 4 小时）进行测量。在非迁徙相，嗅觉和视觉子系统中的 Fos 样免疫反应性（Fos-lir）细胞白天高，夜间低。在迁徙相，这种情况发生了逆转；夜间 Fos-lir 细胞高，白天低。嗅觉和视觉系统的神经活动相位反转与行为转变平行，表明控制迁徙飞行（表现为迁徙躁动）和迁徙定向和导航的系统之间存在功能耦合。
