Guyonnet Audrey E M, Racicot Kelsey J, Brinkman Benjamin, Iwaniuk Andrew N
Department of Neuroscience, University of Lethbridge, 4401 University Dr W, Lethbridge, AB, T1K3M4, Canada.
Brain Struct Funct. 2024 Dec 17;230(1):9. doi: 10.1007/s00429-024-02882-5.
Artificial selection for specific behavioural and physical traits in domesticated animals has resulted in a wide variety of breeds. One of the most widely recognized examples of behavioural selection is the homing pigeon (Columba livia), which has undergone intense selection for fast and efficient navigation, likely resulting in significant anatomical changes to the hippocampal formation. Previous neuroanatomical comparisons between homing and other pigeon breeds yielded mixed results, but only focused on volumes. We completed a more systematic test for differences in hippocampal formation anatomy between homing and other pigeon breeds by measuring volumes, neuron numbers and neuron densities in the hippocampal formation and septum across homing pigeons and seven other breeds. Overall, we found few differences in hippocampal formation volume across breeds, but large, significant differences in neuron numbers and densities. More specifically, homing pigeons have significantly more hippocampal neurons and at higher density than most other pigeon breeds, with nearly twice as many neurons as feral pigeons. These findings suggest that neuron numbers may be an important component of homing behaviour in homing pigeons. Our data also provide the first evidence that neuronal density can be modified by artificial selection, which has significant implications for the study of domestication and interbreed variation in anatomy and behaviour.
对家养动物特定行为和身体特征进行人工选择已产生了各种各样的品种。行为选择最广为人知的例子之一是信鸽（Columba livia），它经过了针对快速高效导航的强烈选择，这可能导致海马结构发生显著的解剖学变化。之前对信鸽和其他鸽种的神经解剖学比较结果不一，但仅关注了体积。我们通过测量信鸽和其他七个鸽种的海马结构及隔膜的体积、神经元数量和神经元密度，对信鸽和其他鸽种的海马结构解剖差异进行了更系统的测试。总体而言，我们发现不同品种间海马结构体积差异不大，但神经元数量和密度存在巨大且显著的差异。更具体地说，信鸽的海马神经元数量明显多于大多数其他鸽种，且密度更高，其神经元数量几乎是野生家鸽的两倍。这些发现表明，神经元数量可能是信鸽归巢行为的一个重要组成部分。我们的数据还首次证明了神经元密度可通过人工选择进行改变，这对驯化以及解剖学和行为方面的品种间变异研究具有重要意义。
