Temperature dependence of electrocommunication signals and their underlying neural rhythms in the weakly electric fish, Apteronotus leptorhynchus
Temperature dependence of electrocommunication signals and their underlying neural rhythms in the weakly electric fish, Apteronotus leptorhynchus
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DOI：
10.1159/000006649
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发表时间：
2000-03-01
影响因子：
1.7
通讯作者：
Yekta, A
中科院分区：
文献类型：
--
作者：
Dunlap, KD;Smith, GT;Yekta, A
弱电鱼类发出的电子通信信号由高度专门化的神经电路控制。在无翅目动物中，连续电器官放电(EOD)是由后脑起搏核团中的电性耦合神经元产生的，而瞬时EOD调制涉及来自中脑下行核团和丘脑前起搏核团的化学突触。我们描述了温度变化(18-32摄氏度)对纤毛虫的连续EOD和EOD调制的影响。EOD频率与温度呈线性相关(q(10)=1.62)。相反，EOD幅值的温度依赖性随温度变化。波幅随温度低于25℃急剧增加(Q(10)=2.0)，但在25℃以上才逐渐增加(Q(10)=1.15)。EOD波形以及相应的谐波含量也受到温度的影响。二次谐波的幅值在低温和高温下都较高，在中温下相对较低。三次谐波的幅值随温度单调增加。因此，温度对排泄物的产生既有定性的影响，也有定量的影响。Chirp速率(Q(10)=3.2)比连续EOD具有更高的温度依赖性，这可能反映了它对化学突触的依赖而不是对电紧性突触的依赖。体外起搏频率Q(10)(1.82)与EOD频率相似，但略高于EOD频率。版权所有(C)2000 S.Karger AG，巴塞尔。
Weakly electric fish emit an electric communication signal that is controlled by a highly specialized neural circuit. In Apteronotus, the continuous electric organ discharge (EOD) is generated by electrotonically coupled neurons in the hindbrain pacemaker nucleus, and transient EOD modulations involve chemical synapses from descending midbrain and thalamic prepacemaker nuclei. We characterized the effects of temperature change (18-32 degrees C) on both the continuous EOD and EOD modulations, chirps, in A. leptorhynchus. EOD frequency was linearly related to temperature (Q(10) = 1.62). By contrast, the temperature dependence of EOD amplitude changed with temperature. Amplitude increased steeply with temperature below 25 degrees C (Q(10) = 2.0), but increased only gradually above 25 degrees C (Q(10) = 1.15). EOD waveform, and consequently harmonic content, was also affected by temperature. The amplitude of the second harmonic was relatively high at both low and high temperature and relatively low at intermediate temperatures. The amplitude of the third harmonic increased monotonically with temperature. Thus, temperature has qualitative as well as quantitative effects on the production of the EOD. Chirp rate (Q(10) = 3.2) had a higher temperature dependence than that of the continuous EOD, which likely reflects its reliance on chemical rather than electrotonic synapses. In vitro pacemaker firing frequency had a similar, but slightly higher Q(10) (1.82) than that of the EOD frequency. Copyright (C) 2000 S. Karger AG, Basel.