Analysis of central synaptic mechanisms underlying behavioral context-dependent posture control in crustaceans10111147

本文介绍了一种新型的光学遥测技术，用于记录水中自由活动动物食管周围连合中枢神经元的放电活动。通过遥测进行的神经记录伴随着动物身体取向、姿势和行为的视频记录，以便分析记录的与动物正在进行的行为相关的尖峰活动。结果表明：1）下行平衡囊中间神经元的锋电位活动与动物处于静止状态或活动状态有关，而另一些中间神经元的锋电位活动与动物处于静止状态或活动状态无关; 2）当动物处于腹部的伸展或屈曲姿势时，某些中间神经元对同一平衡囊的倾斜刺激表现出不同的锋电位活动，和3）响应于平衡囊刺激的行为背景依赖性锋电位活动对于每个个体的中间神经元是一致的和独特的。这些发现表明， 关于我们 这些中间神经元将平衡囊信息从大脑传递到胸神经节（用于行走腿）和腹神经节（用于包括尾足动物的腹足动物）中的运动中心的活性根据动物的行为条件和环境而变化，这表明甲壳类动物的姿势控制不是基于简单的反射，而是基于下行平衡囊中间神经元的可变响应特征的高度适应性行为。遥测实验进一步扩展到分析大脑中的中央神经元，包括下行和本地interneurons的尖峰活动，通过记录它们在细胞外使用钢微电极。为了分析支持平衡囊中间神经元的行为背景依赖性活动的突触机制，还开发了跑步机系统，以用玻璃微电极探测在跑步机上进行步行和腹部姿势运动的动物的大脑。虽然目前还没有分析平衡囊中间神经元，但已经鉴定出当动物启动与姿势控制机制密切相关的行走或腹部姿势运动时，这些中间神经元改变尖峰或突触活动。少

A novel type of optical telemetry was developed from scratch to record the spike activity of central neurons from the circumesophageal commissure of freely behaving animal in the water. The neural recording by the telemetry was accompanied by video recording of the animal body orientation, posture and behavior so that the recorded spike activity was analyzed in relation to ongoing behavior of the animal. It was revealed that 1) the spike activity of descending statocyst interneurons was dependent on whether the animal was quiescent or active in some interneurons but not in others, 2) some interneurons showed different spike activities to the same statocyst stimulation by body tilting depending on whether the animal was engaged in postural extension or flexion of the abdomen at the time of stimulation, and 3) the behavioral context-dependent spike activity in response to statocyst stimulation was consistent and unique to each individual interneuron. These findings demonstrate that the a … More ctivity of those interneurons conveying statocyst information from the brain to motor centers in the thoracic ganglia (for walking legs) and abdominal ganglia (for pleopods including uropods) varies depending on the behavioral condition and context of the animal, suggesting that the crustacean posture control is not based on simple reflexes but is a highly adaptive behavior based on the variable response characteristics of descending statocyst interneurons. The telemetry experiment was further extended to analyze the spike activities of central neurons in the brain, including both descending and local interneurons, by recording them extracellularly using steel microelectrodes. For analyzing the synaptic mechanisms subserving the behavioral context-dependent activities of statocyst interneurons, a treadmill system was also developed to probe with a glass microelectrode the brain of an animal on the treadmill engaged in walking and abdominal posture movements. Although no statocyst interneurons has been analyzed yet presently, those interneurons have been identified that change spike or synaptic activities when the animal initiates walking or abdominal posture movements that are closely associate with the posture control mechanism. Less