A Cholinergic-Regulated Circuit Coordinates the Maintenance and Bi-Stable States of a Sensory-Motor Behavior during Caenorhabditis elegans Male Copulation
A Cholinergic-Regulated Circuit Coordinates the Maintenance and Bi-Stable States of a Sensory-Motor Behavior during Caenorhabditis elegans Male Copulation
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DOI：
10.1371/journal.pgen.1001326
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发表时间：
2011-03-01
期刊：
影响因子：
4.5
通讯作者：
Garcia, L. Rene
中科院分区：
文献类型：
--
作者：
Liu, Yishi;LeBeouf, Brigitte;Garcia, L. Rene
对于大多数陆地交配来说，雄性交配器官穿透到合适的配偶中是一个保守和必要的行为步骤；然而，这种独特的社会相互作用的详细分子和细胞机制尚未在任何动物身上阐明。在交配过程中，秀丽线虫的雄性泄殖腔被保持在两性人的外阴上，因为他试图插入他的交配针状体。当感觉到插入时，有节奏的针刺会停止。由感觉/运动神经元和性肌肉组成的这些步骤的电路组件之前已经被识别出来，但尚不清楚它们的输出是如何整合起来产生协调的行为模式的。在这里，我们表明泄殖腔感觉/运动神经元和后性肌之间的胆碱能信号维持两性之间的生殖器接触。同时，通过缝隙连接，来自这些肌肉的信号被传递到针刺肌，从而将重复的针刺刺与外阴接触结合在一起。在穿透过程中，SPC感觉运动神经元将外阴针刺位置的信号与钩和泄殖腔感受器的输入相结合，以从节律性肌肉收缩转变为持续肌肉收缩。UNC-103K+通道在回路中保持较高的兴奋性阈值，因此持续的针刺肌收缩不会因较少的输入而被刺激。我们证明，用于启动、维持、自我监控和完成先天行为的感觉输入和运动输出的协调是通过几个电路组件的耦合来完成的。
Penetration of a male copulatory organ into a suitable mate is a conserved and necessary behavioral step for most terrestrial matings; however, the detailed molecular and cellular mechanisms for this distinct social interaction have not been elucidated in any animal. During mating, the Caenorhabditis elegans male cloaca is maintained over the hermaphrodite's vulva as he attempts to insert his copulatory spicules. Rhythmic spicule thrusts cease when insertion is sensed. Circuit components consisting of sensory/motor neurons and sex muscles for these steps have been previously identified, but it was unclear how their outputs are integrated to generate a coordinated behavior pattern. Here, we show that cholinergic signaling between the cloacal sensory/motor neurons and the posterior sex muscles sustains genital contact between the sexes. Simultaneously, via gap junctions, signaling from these muscles is transmitted to the spicule muscles, thus coupling repeated spicule thrusts with vulval contact. To transit from rhythmic to sustained muscle contraction during penetration, the SPC sensory-motor neurons integrate the signal of spicule's position in the vulva with inputs from the hook and cloacal sensilla. The UNC-103 K+ channel maintains a high excitability threshold in the circuit, so that sustained spicule muscle contraction is not stimulated by fewer inputs. We demonstrate that coordination of sensory inputs and motor outputs used to initiate, maintain, self-monitor, and complete an innate behavior is accomplished via the coupling of a few circuit components.