Solitary and Gregarious Locusts Differ in Circadian Rhythmicity of a Visual Output Neuron
Solitary and Gregarious Locusts Differ in Circadian Rhythmicity of a Visual Output Neuron
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DOI：
10.1177/0748730412440860
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发表时间：
2012-06-01
影响因子：
3.5
通讯作者：
Matheson, Tom
中科院分区：
文献类型：
--
作者：
Gaten, Edward;Huston, Stephen J.;Matheson, Tom
蝗虫表现出显着的表型可塑性的人口密度的变化驱动。这种密度依赖相多型性与许多生理，行为和形态学的变化，包括观察，神秘的孤独（孤独饲养）的个人开始飞在黄昏，而群居（人群饲养）的个人是白天活跃。我们记录了24-36小时，从一个确定的视觉输出神经元，下降对侧运动检测器（DCMD）的Schistocerca聚集在独居和群居动物。DCMD发出即将发生碰撞的信号，并参与飞行回避机动。DCMD的响应若隐若现的刺激，其特征在于诱发的尖峰和峰值放电率的数量的强度，变化近似正弦曲线的一段时间接近24小时恒定光照下的孤独蝗虫。在群居的个体中，24小时的模式更为复杂，被次级超日节律所改变。DCMD的最强的反应发生在孤独的蝗虫，但到6小时之前，在群居蝗虫，匹配的每种类型的蝗虫是最活跃的一天的时间。因此，我们证明了在群居蝗虫中观察到的行为的时间转变的神经元相关。我们的能力，改变昼夜节律的性质，通过操纵饲养密度相同的光暗周期下的蝗虫可能提供重要的工具，进一步调查的昼夜节律性的机制。
Locusts demonstrate remarkable phenotypic plasticity driven by changes in population density. This density dependent phase polyphenism is associated with many physiological, behavioral, and morphological changes, including observations that cryptic solitarious (solitary-reared) individuals start to fly at dusk, whereas gregarious (crowd-reared) individuals are day-active. We have recorded for 24-36 h, from an identified visual output neuron, the descending contralateral movement detector (DCMD) of Schistocerca gregaria in solitarious and gregarious animals. DCMD signals impending collision and participates in flight avoidance maneuvers. The strength of DCMD's response to looming stimuli, characterized by the number of evoked spikes and peak firing rate, varies approximately sinusoidally with a period close to 24 h under constant light in solitarious locusts. In gregarious individuals the 24-h pattern is more complex, being modified by secondary ultradian rhythms. DCMD's strongest responses occur around expected dusk in solitarious locusts but up to 6 h earlier in gregarious locusts, matching the times of day at which locusts of each type are most active. We thus demonstrate a neuronal correlate of a temporal shift in behavior that is observed in gregarious locusts. Our ability to alter the nature of a circadian rhythm by manipulating the rearing density of locusts under identical light-dark cycles may provide important tools to investigate further the mechanisms underlying diurnal rhythmicity.