Navigational abilities of adult and experienced homing pigeons deprived of olfactory or trigeminally mediated magnetic information
Navigational abilities of adult and experienced homing pigeons deprived of olfactory or trigeminally mediated magnetic information
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DOI：
10.1242/jeb.031864
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发表时间：
2009-10-01
影响因子：
2.8
通讯作者：
Wild, Martin
中科院分区：
文献类型：
--
作者：
Gagliardo, Anna;Ioale, Paolo;Wild, Martin
解剖学证据和条件反射实验表明，受三叉神经眼分支支配的磁感受器位于信鸽的上喙。根据这些发现，有人提出三叉神经介导的磁感受器能够检测磁场强度，这可能有助于鸽子从不熟悉的位置归巢的定位机制。最近的数据表明，在没有经验的鸽子，三叉神经眼分支的部分不损害导航能力。同样，在幼鸽有机会学习导航地图之前，如果对幼鸽进行三叉神经切片，也没有观察到损伤。相比之下，部分嗅觉神经无论是在成年无经验的鸽子或年轻的鸟类在地图学习，扰乱了他们的归巢性能。然而，由于磁地图机制需要训练飞行来学习鸽舍周围区域的磁场梯度，因此问题仍然存在，即缺乏磁场信息是否会影响有经验的成年鸽子的导航性能。为了回答这个问题，我们对成年鸽子进行了广泛的分组训练，然后在测试它们的导航能力之前，通过手术剥夺了它们的嗅觉或三叉神经介导的磁信息。被剥夺三叉神经介导的磁信息的鸟类表现出类似的导航能力，作为完整的控制鸽子，而嗅觉剥夺的鸽子显着受损归巢。我们的数据表明，即使在受过训练的成年鸽子，嗅觉线索需要从不熟悉的位置归巢，缺乏磁信息不会影响导航能力的经验丰富的成年信鸽。
Anatomical evidence and conditioning experiments have suggested that magnetoreceptors innervated by the ophthalmic branch of the trigeminal nerve are located in the upper beak of homing pigeons. Following these findings it has been proposed that the trigeminally-mediated magnetorececeptors are able to detect magnetic field intensity, which might be useful for a position finding mechanism for pigeons homing from unfamiliar locations. Recent data have shown that, in inexperienced pigeons, section of the ophthalmic branch of the trigeminal nerve does not impair navigational abilities. Similarly, no impairment was observed if the trigeminal section was performed on young pigeons, before they have had the opportunity to learn a navigational map. By contrast, section of the olfactory nerve either in adult inexperienced pigeons or in young birds before map learning, disrupted their homing performance. Nevertheless, because a magnetic map mechanism requires training flights for learning the magnetic gradient of the territory around the loft, the question remains as to whether the navigational performance of adult experienced pigeons can be affected by lack of magnetic information. To answer this question we extensively group-trained adult pigeons and then surgically deprived them of either olfactory or trigeminally mediated magnetic information, prior to testing their navigational abilities. The birds deprived of trigeminally mediated magnetic information displayed similar navigational abilities as intact control pigeons, whereas the olfactory-deprived pigeons were dramatically impaired in homing. Our data show that even in trained adult pigeons, olfactory cues are needed for homing from unfamiliar locations and that the lack of magnetic information does not affect navigational abilities of experienced adult homing pigeons.