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

从零开始研制了一种新型的光学遥测仪，用于记录水中自由活动动物食道周围联合的中枢神经元的棘波活动。遥测的神经记录伴随着动物身体方向、姿势和行为的视频记录，因此记录的尖峰活动与动物正在进行的行为有关。结果表明：(1)动物下行状态囊中间神经元的放电活动依赖于某些中间神经元是静止的还是活跃的，但在其他中间神经元中不依赖；(2)对同一状态囊刺激，某些中间神经元对身体倾斜的刺激表现出不同的放电活动，这取决于动物在刺激时是进行姿势伸展还是弯曲腹部；这些发现表明，a…这些中间神经元将状态囊信息从大脑传递到胸神经节(行走的腿)和腹神经节(包括尾足类)中的更多活性取决于动物的行为条件和环境，这表明甲壳动物的姿势控制不是基于简单的反射，而是一种基于下行状态囊中间神经元的可变反应特征的高度适应性行为。遥测实验进一步扩展到分析包括下行神经元和局部中间神经元在内的大脑中枢神经元的放电活动，方法是使用钢微电极进行细胞外记录。为了分析静态囊中间神经元行为上下文相关活动的突触机制，还开发了一种跑步机系统，用玻璃微电极探测跑步机上从事行走和腹部姿势运动的动物的大脑。虽然目前还没有对稳态囊中间神经元的分析，但已经发现这些中间神经元在动物开始行走或腹部姿势运动时会改变棘波或突触活动，而这些动作与姿势控制机制密切相关。较少

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