Gaffin Douglas D, Shakir Safra F
Department of Biology, University of Oklahoma, Norman, OK 73019, USA.
Insects. 2021 Oct 3;12(10):904. doi: 10.3390/insects12100904.
Scorpions have elaborate chemo-tactile organs called pectines on their ventral mesosoma. The teeth of the comb-like pectines support thousands of minute projections called peg sensilla (a.k.a. "pegs"), each containing approximately 10 chemosensory neurons. Males use pectines to detect pheromones released by females, and both sexes apparently use pectines to find prey and navigate to home retreats. Electrophysiological recordings from pegs of reveal three spontaneously active cells (A, A, and B), which appear to interact synaptically. We made long-term extracellular recordings from the bases of peg sensilla and used a combination of conditional cross-interval and conditional interspike-interval analyses to assess the temporal dynamics of the A and B spike trains. Like previous studies, we found that A cells are inhibited by B cells for tens of milliseconds. However, after normalizing our records, we also found clear evidence that the A cells excite the B cells. This simple local circuit appears to maintain the A cells in a dynamic firing range and may have important implications for tracking pheromonal trails and sensing substrate chemistry for navigation.
蝎子在其腹部中体上有称为栉状器的复杂化学触觉器官。梳状栉状器的齿支撑着数千个微小的突起，称为栓状感器（也称为“栓”），每个栓状感器包含大约10个化学感觉神经元。雄性利用栉状器检测雌性释放的信息素，显然两性都利用栉状器寻找猎物并导航回到栖息地。来自栓状感器的电生理记录显示出三个自发活动的细胞（A、A和B），它们似乎通过突触相互作用。我们从栓状感器基部进行了长期细胞外记录，并使用条件交叉间隔和条件峰峰间隔分析相结合的方法来评估A和B神经元放电序列的时间动态。与之前的研究一样，我们发现A细胞会被B细胞抑制数十毫秒。然而，在对我们的记录进行归一化处理后，我们还发现了明确的证据表明A细胞会兴奋B细胞。这个简单的局部回路似乎能使A细胞维持在动态放电范围内，并且可能对追踪信息素踪迹和感知底物化学以进行导航具有重要意义。
