Objective: The passive electrosense is a primitive sensory modality in the Chondrostei, which include sturgeon and paddlefish. Using electroreceptors, these fish detect the weak electric fields from other animals or geoelectric sources, and use this information for prey detection or other behaviors. The primary afferent fibers innervating the electroreceptors project to a single hindbrain target called the dorsal octavolateral nucleus (DON), where the electrosensory information is first processed. Here, we investigated the electrophysiological properties of DON neurons.
Methods: Extracellular recording was used to investigate the response properties of DON neurons to dipole electric fields with different amplitudes and frequencies in the white sturgeon, Acipenser transmontanus.
Results: The DON neurons showed regular spontaneous activity and could be classified into two types: neurons with a low spontaneous rate (<10 Hz) and those with a high spontaneous rate (>10 Hz). In response to sinusoidal electric field stimuli, DON neurons showed sinusoidally-modulated and phase-locked firing. In addition, neurons showed opposite phase responses corresponding to the different directions of the dipole.
Conclusion: The response properties of DON neurons match the electrosensory biological function in sturgeon, as they match the characteristics of the electric fields of its prey.
目的: 软骨硬鳞鱼类的电感受是一种古老的感觉系统, 它们通过电感受器官感受生物电场或非生物电场进行摄食等活动。支配电感受器的初级传入神经首先将电感受信息传递至后脑的背听侧核进行处理。本文探讨了鲟鱼背听侧核的电生理特性。
方法: 采用胞外记录方法记录了高首鲟背听侧核在偶极子电场刺激下的神经元反应。
结果: 背听侧核神经元有低频(<10 Hz)自发放电和高频(>10 Hz)自发放电两种, 在电场刺激下均产生明显的自发放电的调制和相位耦合反应, 同时部分神经元对偶极子电场的方向有选择性。
结论: 鲟鱼的电感受神经元反应特征与其电感受的生物功能相适应。