Isko Emily C, Harpole Clifford E, Zheng Xiaoyue Mike, Zhan Huiqing, Davis Martin B, Zador Anthony M, Banerjee Arkarup
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY.
Cold Spring Harbor Laboratory School for Biological Sciences, Cold Spring Harbor, NY.
bioRxiv. 2024 Oct 24:2024.09.13.612752. doi: 10.1101/2024.09.13.612752.
Deciphering how cortical architecture evolves to drive behavioral innovations is a long-standing challenge in neuroscience and evolutionary biology. Here, we leverage a striking behavioral novelty in the Alston's singing mouse (), compared to the laboratory mouse (), to quantitatively test models of motor cortical evolution. We used bulk tracing, serial two-photon tomography, and high-throughput DNA sequencing of over 76,000 barcoded neurons to discover a specific and substantial expansion (200%) of orofacial motor cortical (OMC) projections to the auditory cortical region (AudR) and the midbrain periaqueductal gray (PAG), both implicated in vocal behaviors. Moreover, analysis of individual OMC neurons' projection motifs revealed preferential expansion of exclusive projections to AudR. Our results imply that selective expansion of ancestral motor cortical projections can underlie behavioral divergence over short evolutionary timescales, suggesting potential mechanisms for the evolution of enhanced cortical control over vocalizations-a crucial preadaptation for human language.
解读皮质结构如何演化以驱动行为创新，是神经科学和进化生物学中长期存在的挑战。在这里，我们利用奥氏歌鼠与实验室小鼠相比显著的行为新奇性，来定量测试运动皮质进化模型。我们使用大量追踪、串行双光子断层扫描以及对超过76000个带条形码神经元的高通量DNA测序，发现口面部运动皮质（OMC）向听觉皮质区域（AudR）和中脑导水管周围灰质（PAG）的投射有特定且显著的扩展（200%），这两个区域都与发声行为有关。此外，对单个OMC神经元投射模式的分析揭示了向AudR的排他性投射的优先扩展。我们的结果表明，祖先运动皮质投射的选择性扩展可能是短进化时间尺度上行为分化的基础，这为增强皮质对发声的控制的进化提供了潜在机制——这是人类语言的关键预适应。
