Marshall C D, Reep R L
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610.
Brain Behav Evol. 1995;45(1):1-18. doi: 10.1159/000113381.
In several brains of the Florida manatee, Trichechus manatus latirostris, the architecture of caudal regions of cerebral cortex was examined in order to complete a map of cortical areas in the brain of this unique herbivore. Through observation of sections stained for Nissl substance, myelinated axons, acetylcholinesterase and cytochrome oxidase, we have identified 11 new cortical areas based on qualitative cytoarchitectural appearance and measurements of laminar thicknesses, for a total of 24 such cortical areas in manatee cerebral cortex. Some areas exhibit poorly differentiated laminae while in others there are 6 clearly demarcated layers, often with sublaminar organization. Some previously identified areas were found to extend into the region caudal to the vertically oriented lateral fissure. As in other mammalian brains, cortical areas in manatees are organized in concentric rings of allocortex, mesocortex, and isocortex. Putative functional roles have been assigned to most of the identified areas based on location, architecture, behavioral and anatomical considerations, and extrapolation from other taxa in which functional mapping has been done.
在几只佛罗里达海牛（Trichechus manatus latirostris）的大脑中，对大脑皮层尾部区域的结构进行了检查，以便完成这种独特食草动物大脑皮层区域的图谱绘制。通过观察尼氏物质染色切片、有髓轴突、乙酰胆碱酯酶和细胞色素氧化酶，我们基于定性的细胞结构外观和层厚测量，确定了11个新的皮层区域，海牛大脑皮层中此类皮层区域总数达到24个。一些区域的层分化较差，而其他区域有6个明显划分的层，通常还有亚层组织。一些先前确定的区域被发现延伸到垂直方向的外侧裂尾侧区域。与其他哺乳动物的大脑一样，海牛的皮层区域由原皮质、中皮质和新皮质的同心环组成。基于位置、结构、行为和解剖学考虑，以及从已进行功能图谱绘制的其他分类群进行推断，已为大多数已确定的区域赋予了假定的功能作用。
