Spatiotemporal Patterns of Contact Across the Rat Vibrissal Array During Exploratory Behavior.
Spatiotemporal Patterns of Contact Across the Rat Vibrissal Array During Exploratory Behavior.
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DOI：
10.3389/fnbeh.2015.00356
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发表时间：
2015
影响因子：
3
通讯作者：
Hartmann MJ
中科院分区：
文献类型：
--
作者：
Hobbs JA;Towal RB;Hartmann MJ
大鼠触须系统是研究躯体感觉的重要模型，但是触须的小尺寸和快速速度已经排除了在行为期间测量精确的触须-物体接触序列。我们使用激光光片以1 ms的分辨率量化胡须表面接触的时空结构，因为五只幼稚大鼠自由探索平坦的垂直玻璃墙。与以前的工作一致，我们表明，搅拌周期不能被唯一定义，因为不同的晶须往往异步移动，但头部速度的准周期性（~8 Hz）变化代表了一个独特的时间特征，锁定分析。在最小头部速度的时间附近，晶须伸长以与表面接触，然后在分离之前与表面保持长时间接触（约25-60 ms）。这种行为导致离散的时间窗口，其中大量的晶须与表面接触。在所有5只大鼠的100%搅拌器上观察到这些“持续集体接触间隔”（SCCI）。可以根据有关头部姿势和平均搅拌周期的信息定性预测SCCI的整体时空结构。相反，须表面接触的精确序列取决于详细的头部和须运动学。触须接触的序列是高度可变的，同样可能在整个阵列的各个方向传播。有些更多的结构时，发现接触的序列进行了检查，逐行的基础上。与接触顺序相关的高可变性形成鲜明对比的是，每个SCCI的一致特征是玻璃上晶须的接触位置在片材上会聚并移动得更慢。总之，这些研究结果使我们提出，大鼠使用的“窗口采样”的策略来提取对象的空间特征：具体地说，大鼠在空间上整合了准静态的机械信号在持续接触期间，类似于一个“封闭”的触觉程序的胡须。
The rat vibrissal system is an important model for the study of somatosensation, but the small size and rapid speed of the vibrissae have precluded measuring precise vibrissal-object contact sequences during behavior. We used a laser light sheet to quantify, with 1 ms resolution, the spatiotemporal structure of whisker-surface contact as five naïve rats freely explored a flat, vertical glass wall. Consistent with previous work, we show that the whisk cycle cannot be uniquely defined because different whiskers often move asynchronously, but that quasi-periodic (~8 Hz) variations in head velocity represent a distinct temporal feature on which to lock analysis. Around times of minimum head velocity, whiskers protract to make contact with the surface, and then sustain contact with the surface for extended durations (~25–60 ms) before detaching. This behavior results in discrete temporal windows in which large numbers of whiskers are in contact with the surface. These “sustained collective contact intervals” (SCCIs) were observed on 100% of whisks for all five rats. The overall spatiotemporal structure of the SCCIs can be qualitatively predicted based on information about head pose and the average whisk cycle. In contrast, precise sequences of whisker-surface contact depend on detailed head and whisker kinematics. Sequences of vibrissal contact were highly variable, equally likely to propagate in all directions across the array. Somewhat more structure was found when sequences of contacts were examined on a row-wise basis. In striking contrast to the high variability associated with contact sequences, a consistent feature of each SCCI was that the contact locations of the whiskers on the glass converged and moved more slowly on the sheet. Together, these findings lead us to propose that the rat uses a strategy of “windowed sampling” to extract an object's spatial features: specifically, the rat spatially integrates quasi-static mechanical signals across whiskers during the period of sustained contact, resembling an “enclosing” haptic procedure.