Functional architecture of the mystacial vibrissae
Functional architecture of the mystacial vibrissae
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DOI：
10.1016/s0166-4328(97)83328-1
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发表时间：
1997-03-01
影响因子：
2.7
通讯作者：
Merzenich, MM
中科院分区：
文献类型：
--
作者：
Brecht, M;Preilowski, B;Merzenich, MM
通过形态学和行为学的比较分析，探讨了大鼠神秘触须的转导、运作和功能。在一系列哺乳动物中记录了触须结构，以确定触须组织的进化保守特征。作为这个分析的结果，我们区分了前缘微振动系统和神秘垫的大振动系统。后者总是由排列整齐的胡须组成。在每一排中，胡须的方向垂直于动物的背掌轴；它们都有一个特定的背腹朝向。在所有物种中，在任何振动排中，从吻侧到尾侧，须的长度都精确地呈指数增长。每一个须状物似乎都像一个杠杆一样的换能器，提供关于个体触须是否偏转的信息，而不是在哪里偏转。研究发现，大鼠额部微触须系统的触须尖密度约为神秘部大触须的40倍。在行为研究中，空间任务和目标识别任务用于研究(a)搜索行为；(b)单晶须运动；(c)物体识别能力；(d)选择性去除宏观或微触须对任务表现的影响。这些研究表明，大触须和微触须的功能作用有明显的区别。神秘大触须在空间任务中起关键作用，但在物体识别中不是必需的。微触须在物体识别任务中起关键作用，但在空间任务中不是必需的。综合这些形态学和行为学数据得出以下功能概念：神秘大触须行是一个距离解码器。它的功能是导出以头部为中心的障碍物/开口轮廓，以振动行表示的各种背腹角。该距离探测器模型在功能上与传统的须功能概念有很大不同，传统的须功能概念假设神秘须形成细颗粒皮肤状物体识别触觉表面。
We investigated the transduction operation and function of the mystacial vibrissae, using a comparative morphological analysis and behavioral experiments in rats. Vibrissal architecture was documented in a series of mammals to identify evolutionary conserved features of vibrissal organization. As a result of this analysis, we distinguish between a frontal microvibrissal system and macrovibrissal system of the mystacial pad. The latter was invariably comprised of whiskers aligned in regular rows. In each row, whiskers were oriented perpendicular to the animal's rostrocaudal axis; all shared a specific dorsoventral orientation. In all species, progressing from rostral to caudal in any vibrissal row, there was a precisely exponential increase in whisker length. Each whisker appeared to act as a lever-like transducer, providing information as to whether or not - but not where - an individual vibrissa had been deflected. The rat's frontal microvibrissae system was found to have a vibrissa tip density that was about 40 times higher than that of the mystacial macrovibrissae. In behavioral studies spatial tasks and object recognition tasks were used to investigate (a) search behaviors; (b) single whisker movements; (c) object recognition ability; and (d) effects of selective macro- or microvibrissae removal on task performances. A clear distinction between the functional roles of macro- and microvibrissae was demonstrated in these studies. Mystacial macrovibrissae were critically involved in spatial tasks, but were not essential for object recognition. Microvibrissae were critically involved in object recognition tasks, but were not essential for spatial tasks. A synthesis of these morphological and behavioral data led to the following functional concept: The mystacial macrovibrissae row is a distance decoder. Its function is to derive head centered obstacle/opening contours at the various dorsoventral angles represented by vibrissal rows. This distance detector model is functionally very different from traditional concepts of whisker function, in which the mystacial whiskers were hypothesized to form a fine grain skin-like object-recognizing tactile surface.