Watson G M, Venable S, Mire P
Department of Biology, University of Southwestern Louisiana, Lafayette, Louisiana 70504-2451, USA.
J Exp Zool. 2000 Feb 15;286(3):262-9.
Sea anemones capture prey by discharging nematocysts and other cnidae. Discharge of microbasic p-mastigophore (mpm) nematocysts is regulated in part by hair bundle mechanoreceptors on tentacles arising from multicellular complexes consisting of supporting cells and a sensory neuron. Anemone hair bundles detect movements of prey and then sensitize cnidocytes (cnida-containing cells) to discharge mpm nematocysts in response to contact between the prey and tentacle. Data from a simple bioassay based on counting nematocysts discharged into test probes, indicate that approximately twice as many nematocysts discharge into test probes touched to tentacles after sensitization than before sensitization. We here report that sub-second bursts of vibrational stimuli at key frequencies (51, 55, 65, or 74 Hz; Watson GM, Mire P, Hudson RR. 1998. J Exp Zool 281:582-593) sensitize discharge for at least 90 sec. Very few complete cycles of vibration are sufficient to sensitize discharge. However, as the number of cycles of vibration is increased, discharge is sensitized in rhythmic patterns. Computer analysis of the data by fast Fourier transforms indicates discharge to vibrations at 65 Hz is sensitized every 6.75 cycles. At 51 Hz discharge is sensitized every 2.00 cycles. At 74 Hz, discharge is sensitized in a polyrhythm occurring every 4.26, 3.76, 2.46, and 2. 10 cycles, respectively. At 55 Hz, discharge is sensitized in a polyrhythm occurring every 6.09, 3.20, 2.91, and 2.0 cycles, respectively. Apparently, cells in the neuronal pathway interconnecting anemone hair bundles with cnidocytes count cycles of vibration and then sensitize discharge or not according to the tally. J. Exp. Zool. 286:262-269, 2000.
海葵通过释放刺丝囊和其他刺细胞来捕获猎物。微基型p-鞭毛型（mpm）刺丝囊的释放部分受触手上海毛束机械感受器的调节，这些海毛束源自由支持细胞和感觉神经元组成的多细胞复合体。海葵的海毛束检测猎物的运动，然后使刺细胞（含刺丝囊的细胞）敏感，以便在猎物与触手接触时释放mpm刺丝囊。基于对释放到测试探针中的刺丝囊进行计数的简单生物测定数据表明，致敏后接触触手的测试探针中释放的刺丝囊数量大约是致敏前的两倍。我们在此报告，关键频率（51、55、65或74赫兹；沃森GM、米尔P、哈德森RR。1998年。《实验动物学杂志》281:582 - 593）下亚秒级的振动刺激脉冲可使释放敏感至少90秒。极少的完整振动周期就足以使释放敏感。然而，随着振动周期数增加，释放以有节奏的模式变得敏感。通过快速傅里叶变换对数据进行计算机分析表明，65赫兹振动时每6.75个周期释放就会变得敏感。51赫兹时每2.00个周期释放变得敏感。74赫兹时，释放以多节奏变得敏感，分别每4.26、3.76、2.46和2.10个周期出现一次。55赫兹时，释放以多节奏变得敏感，分别每6.09、3.20、2.91和2.0个周期出现一次。显然，在将海葵海毛束与刺细胞相互连接的神经通路中的细胞对振动周期进行计数，然后根据计数结果决定是否使释放敏感。《实验动物学杂志》286:262 - 269，2000年。
