Departamento de Ciencias Biológicas, Universidad de Los Andes, Apartado Aereo 4976, Bogotá, Colombia.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Nov;195(11):1031-41. doi: 10.1007/s00359-009-0477-9. Epub 2009 Sep 17.
The metatarsal lyriform organ of the spider Cupiennius salei is a vibration detector consisting of 21 cuticular slits supplied by two sensory cells each, one ending in the outer and the other at the inner slit membrane. In search of functional differences between the two cell types due to differences in stimulus transmission, we analyzed (1) the adaptation of responses to electrical stimulation, (2) the thresholds for mechanical stimulation and (3) the representation of male courtship vibrations using intracellular recording and staining techniques. Single- and multi-spiking receptor neurons were found among both cell types, which showed high-pass filter characteristics. Below 100-Hz threshold, tarsal deflections were between 1 degrees and 10 degrees. At higher frequencies, they decreased down to values as small as 0.05 degrees, corresponding to 4.5-nm tarsal deflection in the most sensitive cases. Different slits in the organ and receptor cells with slow or fast adaptation did not differ in this regard. When stimulated with male courtship vibrations, both types of receptor cells again did not differ significantly regarding number of action potentials, latency and synchronization coefficients. Surprisingly, the differences in dendrite coupling were not reflected by the physiological responses of the two cell types innervating the slits.
节胸蛛的跗节栉状器是一个由 21 个表皮狭缝组成的振动感受器，每个狭缝由两个感觉细胞供应，一个终止于外狭缝膜，另一个终止于内狭缝膜。为了寻找由于刺激传递的不同而导致的两种细胞类型之间的功能差异，我们分析了（1）对电刺激的反应的适应，（2）机械刺激的阈值，以及（3）使用细胞内记录和染色技术对雄性求偶振动的表示。在两种细胞类型中都发现了单峰和多峰受体神经元，它们表现出高通滤波器特性。在 100 Hz 阈值以下，跗节的偏转在 1 到 10 度之间。在更高的频率下，它们下降到只有 0.05 度的小值，在最敏感的情况下对应于 4.5nm 的跗节偏转。在器官中的不同狭缝和具有慢或快适应的受体细胞在这方面没有差异。当用雄性求偶振动刺激时，两种类型的受体细胞在动作电位的数量、潜伏期和同步系数方面也没有显著差异。令人惊讶的是，两种支配狭缝的细胞类型在树突耦合上的差异并没有反映在它们的生理反应中。
