New Approaches for Investigating Brain-Body Scaling and the Evolution of Mammalian Brains

研究脑-体尺度和哺乳动物大脑进化的新方法大脑大小在行为和智力中的重要性仍然是神经科学研究的一个基本领域。 世纪以来，生物学家一直对大脑大小如何随着身体大小的增加而变化以及这对不同物种行为复杂性的暗示感兴趣。 特别是人类和其他灵长类动物的大脑比我们的身体尺寸所预测的要大得多，这被认为是我们独特的智力能力的基础。 在这个项目中，卡塔尼亚博士将测试一个假设，即具有更多感官输入或更复杂运动行为的动物，其大脑比从其身体大小预测的要大，以处理更大的输入或输出。 具体来说，他将调查身体大小和大脑大小之间的比例关系，以及鼹鼠（Talpidae科）和鼩（Soricidae科）的感觉或运动专业化程度。 这些物种非常适合此类研究，因为这些哺乳动物与其他哺乳动物和人类共享许多共同的大脑特征，但在更高的处理，新皮层区域有特别明确的细分。 这些清晰的大脑分区在大脑较大的哺乳动物中是不可见的。 研究鼩 鼱和鼹鼠将允许精确量化大脑中与每个物种的视觉，体感或听觉发育程度相关的区域。 将收集的具体数据包括大脑输入（传入）计数和大脑输出（传出）计数。 此外，这些数量将与每个物种个体的大脑大小和身体大小进行比较。 这些研究的主要目的是揭示大脑大小，身体大小和感觉能力之间先前未确定的关系。 最终，这项研究可能会告诉我们哺乳动物大脑的一般比例原则，这将有助于我们理解智力的进化。

New Approaches for Investigating Brain-Body Scaling and the Evolution of Mammalian Brains The significance of brain size in behavior and intelligence remains a fundamental area of study in the neurosciences. For well over a century biologists have been interested in how brain size scales with increasing body size and what this suggests about behavioral complexity in different species. Humans and other primates in particular have a much larger brain than would be predicted for our body size and this is thought to underlie our unique intellectual abilities. In this project, Dr. Catania will test the hypothesis that animals with more sensory input or more complex motor behavior have larger brains than would be predicted from their body size to process the greater input or output. Specifically he will investigate the scaling relationship between body size and brain size and the degree of sensory or motor specializations in moles (Family Talpidae) and shrews (Family Soricidae). These species are well-suited for such studies because these mammals share many brain features in common with other mammals and humans, but have particularly clear subdivisions in the higher processing, neocortical areas. These clear brain subdivisions are not visible in larger brained mammals. Studying shrews and moles will allow precise quantification of areas in the brain that can be related to the degree of development of the visual, somatosensory, or auditory senses in each species. The specific data that will be collected include counts of inputs (afferents) to the brain and counts of output (efferents) from the brain. In addition, the quantities will be compared with brain size and body size in individuals from each species. The primary goal of these studies is to reveal previously unidentified relationships between brain size, body size, and sensory abilities. Ultimately the research may inform us about scaling principles general to mammalian brains that will help us to understand the evolution of intelligence.