SENSORIMOTOR CORTEX IN PROSIMIAN PRIMATE

近20年来躯体感觉研究的长期目标 在原猴灵长类系统中，加拉戈是一种理解角色 脑内初级(SI)和次级(SII)皮质投射区 触觉辨别能力。在成年的Galago中，神经元位于 丘脑腹后部(VP)投射到SI或SII，而在 幼年，许多VP神经元向SI和SII发出侧支。在成人中 类人，VPL只投射到SI，SII接受触觉输入 间接通过SI。来自有毛(H)和无毛(G)手的输入 年对SI和SII的分离和单独组织的地区的项目 成年的加拉戈。这与新旧SI区和SII区的对比 世界类人猿，其中主要的G输入掩盖了次要的H输入 从手中。因此，建议：1)地方(SI或SII) NOR通道(H或G)对于早期指导最初的发育很重要 在所有灵长类动物的发育中；2)VP神经元向 SI和SII最终G区和H区；以及外周和皮质 活动会影响最终的投影模式。在加拉戈，我抵押品 消除可能发生在亚情态的基础上，而在类人猿中， 根据皮质轨迹(所有SII侧支均被剔除)。 为了检验基于这种建议的预测，对C和H输入的研究 对婴儿和成人Galago的SI和SII提出：1) 电生理研究将检查大小、亚模式和 从手到SI的3b区和1区的输入的地形组织 婴儿和成人的SII背侧区和腹侧区；2) 使用多种荧光染料的解剖学研究将检查 向SI和SII区的投射模式(通常是 分离为G区和H区)在正常婴儿和成人中；3)研究 使用长期荧光标记将确定时间模式1 在正常动物和实验动物中维持的VP投射(与 消除婴儿或成人的H输入、SI或SII)；4)和歧视 将提出评估动物触觉能力的任务，包括 在SI或SII中产生的G输入的扩展和/或复制 操纵。这些研究对机理有影响：1) 调节正常的皮质和行为发育；2)恢复 早期脑损伤后的功能；3)脑损伤的形态学基础 成人外周病变后输入的“去掩蔽”；5) 导致皮质增高症演变的发育机制 灵长类动物的体型和复杂性。

The longterm goal of the last 20 years of study of the somatic sensory system in the prosimian primate, Galago, is an understanding of the role of the primary (SI) and secondary (SII) cortical projections areas in tactile discrimination capacity. In the adult Galago, neurons in the ventroposterior (VP) thalamus project to either SI or SII, whereas in the infant, many VP neurons extend collaterals to both SI and SII. In adult anthropoids, VPL projects only to SI, and SII receives tactile input indirectly through SI. Input from the hairy (H) and glabrous (G) hand projects to segregated and separately organized regions of SI and SII in the adult Galago. This contrast with SI and SII areas in Old and New World anthropoids, in which the major G input obscures the minor H input from the hand. Hence it is proposed: 1) that neither place (SI or SII) nor modality (H or G) are important in directing initial outgrowth early in development of all primates; 2) that VP neurons extend collaterals to the eventual G and H zones of SI and SII; and that peripheral and cortical activity influences the final projection pattern. In Galago, I collateral elimination may occur on the basis of submodality, whereas in anthropoids, on the basis of cortical locus (all SII collaterals are eliminated). To examine predictions based on such a proposal, studies of C and H input to SI and SII in infant and adult Galago are proposed: 1) electrophysiological studies will examine the size, submodality and topographic organization of input from the hand to areas 3b and 1 of SI and of dorsal and ventral zones of SII in infants and adults; 2) anatomical studies using multiple fluorescent dyes will examine the pattern of projections to these zones of SI and SII (which are normally segregated into G and H areas) in normal infants and adults; 3) studies using long-term fluorescent labels will determine the temporal 1 pattern of maintained VP projections in normal and experimental animals (with removal of H input, SI or SII as infants or adults); 4) and discrimination tasks will be presented to evaluate tactile capacity in animals, with expansions and/or duplications of G input in SI or SII, produced by such manipulations. These studies have implications for mechanism: 1) mediating normal cortical and behavioral development; 2) the recovery of function after early brain damage; 3) the morphological basis for the "unmasking" of input after peripheral lesions in adults; and 5) the developmental mechanisms leading to the evolution of increased cortical size and complexity in primates.