Control of cricket stridulation by a command neuron: Efficacy depends on the behavioral state
Control of cricket stridulation by a command neuron: Efficacy depends on the behavioral state
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DOI：
10.1152/jn.2000.83.2.712
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发表时间：
2000-02-01
影响因子：
2.5
通讯作者：
Hedwig, B
中科院分区：
文献类型：
--
作者：
Hedwig, B
蟋蟀使用不同的歌曲模式进行声音交流。发声模式生成网络位于胸神经节内，但由大脑控制。通过脑神经元的细胞内记录和染色来识别这种对发声的下降控制。在休息和发声的蟋蟀以及谷物风刺激期间分析了它对鸣叫声产生的影响，这损害了发声运动并引起短暂的沉默反应。大脑中的下行中间神经元充当叫歌颤音的命令神经元。神经元具有背侧躯体位置、前树突和在对侧结缔中下降的轴突。神经元存在于中枢神经系统的每一侧。它在休息的蟋蟀中不会被激活。中间神经元的细胞内去极化使其尖峰频率增加到 60-80 尖峰/秒，可靠地引起鸣叫鸣叫。尖峰频率在线性调频脉冲周期中进行轻微调制，最大活动与每个线性调频脉冲同相。线性调频重复率与中间神经元的尖峰频率之间存在高度正相关。然而，音节重复率和中间神经元活动之间仅存在非常弱的相关性。命令神经元的有效性取决于蟋蟀的活动状态。在休息的蟋蟀中，通过实验诱发的动作电位的短暂爆发只能引起不完整的鸣叫声。在之前在实验期间发出鸣叫声的蟋蟀中，中间神经元活动的短暂激发可以触发持续的鸣叫声，在此期间，中间神经元表现出类似于 30 脉冲/秒的脉冲频率。在持续的叫声过程中，命令神经元的活动对于维持发声行为是必要的。抑制中间神经元会停止发声。中间神经元尖峰频率的瞬时增加加速了线性调频脉冲速率，从而重置线性调频脉冲模式发生器的定时。中间神经元也会因谷物风的刺激而兴奋。谷物风刺激会损害鸣叫和音节产生的模式，但这些变化并没有反映在命令神经元的放电模式中。在风引起的沉默反应期间，鸣叫命令神经元的活性保持不变，但在这些条件下，其活性不再足以维持发声。因此，发声可以通过来自终末神经节的谷物输入来抑制，而不直接抑制下行命令活动。
Crickets use different song patterns for acoustic communication. The stridulatory pattern-generating networks are housed within the thoracic ganglia but are controlled by the brain. This descending control of stridulation was identified by intracellular recordings and stainings of brain neurons. Its impact on the generation of calling song was analyzed both in resting and stridulating crickets and during cereal wind stimulation, which impaired the stridulatory movements and caused transient silencing reactions. A descending interneuron in the brain serves as a command neuron for calling-song stridulation. The neuron has a dorsal soma position, anterior dendritic processes, and an axon that descends in the contralateral connective. The neuron is present in each side of the CNS. It is not activated in resting crickets. Intracellular depolarization of the interneuron so that its spike frequency is increased to 60-80 spikes/s reliably elicits calling-song stridulation. The spike frequency is modulated slightly in the chirp cycle with the maximum activity in phase with each chirp. There is a high positive correlation between the chirp repetition rate and the interneuron's spike frequency. Only a very weak correlation, however, exists between the syllable repetition rate and the interneuron activity. The effectiveness of the command neuron depends on the activity state of the cricket. In resting crickets, experimentally evoked short bursts of action potentials elicit only incomplete calling-song chirps. In crickets that previously had stridulated during the experiment, short elicitation of interneuron activity can trigger sustained calling songs during which the interneuron exhibits a spike frequency of similar to 30 spikes/s. During sustained calling songs, the command neuron activity is necessary to maintain the stridulatory behavior. Inhibition of the interneuron stops stridulation. A transient increase in the spike frequency of the interneuron speeds up the chirp rate and thereby resets the timing of the chirp pattern generator. The interneuron also is excited by cereal wind stimulation. Cereal wind stimulation can impair the pattern of chirp and syllable generation, but these changes are not reflected in the discharge pattern of the command neuron. During wind-evoked silencing reactions, the activity of the calling-song command neuron remains unchanged, but under these conditions, its activity is no longer sufficient to maintain stridulation. Therefore stridulation can be suppressed by cereal inputs from the terminal ganglia without directly inhibiting the descending command activity.