Crayfish escape from threatening stimuli by tailflipping. If a stimulus is applied to the rear, crayfish escape up and forwards in a summersault maneuver that is mediated by the activation of lateral giant (LG) interneurons. The occurrence probability of LG-mediated tailflip, however, diminishes and habituates if a stimulus is repeatedly applied. Since crayfish have a relatively simple CNS with many identifiable neurons, crayfish represent a good animal to analyze the cellular basis of habituation. A reduction in the amplitude of the EPSP in the LGs, caused by direct chemical synaptic connection from sensory afferents by repetitive stimulations, is essential to bring about an inactivation of the LGs. The spike response of the LGs recovers within several minutes of habituation, but the LGs subsequently fail to spike when an additional stimulus is applied after specific periods following habituation. These results indicate that a decline in synaptic efficacy from the mechanosensory afferents recovers readily after a short delay, but then the excitability of the LGs themselves decreases. Furthermore, the processes underlying habituation are modulated depending on a social status. When two crayfish encounter each other, a winner–loser relationship is established. With a short interstimulus interval of 5 s, the rate of habituation of the LG in both socially dominant and subordinate crayfish becomes lower than in socially isolated animals. Serotonin and octopamine affect this social status-dependent modulation of habituation by means of activation of downstream second messenger system of cAMP and IP₃ cascades, respectively.

中文翻译：

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小龙虾中LG介导的尾巴习性的习性。

小龙虾通过甩尾逃脱威胁性刺激。如果对尾部施加刺激，则小龙虾会在由侧向巨型（LG）中神经元激活介导的避暑行动中向上和向前逃逸。但是，如果反复施加刺激，LG介导的尾部翻转的发生概率会降低并趋于适应。由于小龙虾具有相对简单的中枢神经系统，具有许多可识别的神经元，因此小龙虾代表了一种分析习惯性细胞基础的好动物。LGs的失活是由LG的重复刺激引起的感觉传入的直接化学突触连接引起的LGs EPSP振幅的降低。LG的尖峰响应会在习惯的几分钟内恢复，但是当习惯化后的特定时间段之后，如果施加额外的刺激，则LG便无法突增。这些结果表明，机械感觉传入的突触效力下降在短暂的延迟后很容易恢复，但是LG自身的兴奋性下降。此外，根据社会地位来调节习惯化的基础过程。当两个小龙虾相遇时，就会建立起赢家/输家的关系。在5 s的短暂刺激间隔内，社交小龙虾和从属小龙虾的LG习惯化率都低于社交孤立的动物。5-羟色胺和章鱼胺通过激活cAMP和IP的下游第二信使系统来影响这种依赖于社会地位的习惯调节分别为₃级联。