Coombs Sheryl, New John G, Nelson Mark
Parmly Hearing Institute and Biology Department, Loyola University Chicago, 6525 N. Sheridan Rd., Chicago, IL 60626, USA.
J Physiol Paris. 2002 Sep-Dec;96(5-6):341-54. doi: 10.1016/S0928-4257(03)00013-5.
The electrosensory and mechanosensory lateral line systems of fish exhibit many common features in their structural and functional organization, both at the sensory periphery as well as in central processing pathways. These two sensory systems also appear to play similar roles in many behavioral tasks such as prey capture, orientation with respect to external environmental cues, navigation in low-light conditions, and mediation of interactions with nearby animals. In this paper, we briefly review key morphological, physiological, and behavioral aspects of these two closely related sensory systems. We present arguments that the information processing demands associated with spatial processing are likely to be quite similar, due largely to the spatial organization of both systems and the predominantly dipolar nature of many electrosensory and mechanosensory stimulus fields. Demands associated with temporal processing may be quite different, however, due primarily to differences in the physical bases of electrosensory and mechanosensory stimuli (e.g. speed of transmission). With a better sense of the information processing requirements, we turn our attention to an analysis of the functional organization of the associated first-order sensory nuclei in the hindbrain, including the medial octavolateral nucleus (MON), dorsal octavolateral nucleus (DON), and electrosensory lateral line lobe (ELL). One common feature of these systems is a set of neural mechanisms for improving signal-to-noise ratios, including mechanisms for adaptive suppression of reafferent signals. This comparative analysis provides new insights into how the nervous system extracts biologically significant information from dipolar stimulus fields in order to solve a variety of behaviorally relevant problems faced by aquatic animals.
鱼类的电感受和机械感受侧线系统在其结构和功能组织上，无论是在感觉外周还是在中枢处理通路中，都表现出许多共同特征。这两种感觉系统在许多行为任务中似乎也发挥着相似的作用，比如捕食、根据外部环境线索定向、在弱光条件下导航以及介导与附近动物的相互作用。在本文中，我们简要回顾这两个密切相关的感觉系统的关键形态学、生理学和行为学方面。我们提出这样的观点，即与空间处理相关的信息处理需求可能非常相似，这主要是由于这两个系统的空间组织以及许多电感受和机械感受刺激场的主要偶极性质。然而，与时间处理相关的需求可能有很大不同，这主要是由于电感受和机械感受刺激的物理基础存在差异（例如传播速度）。在对信息处理需求有了更清晰的认识之后，我们将注意力转向对后脑相关一级感觉核团功能组织的分析，包括内侧八分体外侧核（MON）、背侧八分体外侧核（DON）和电感受侧线叶（ELL）。这些系统的一个共同特征是一组用于提高信噪比的神经机制，包括对再传入信号进行适应性抑制的机制。这种比较分析为神经系统如何从偶极刺激场中提取生物学上有意义的信息以解决水生动物面临的各种行为相关问题提供了新的见解。
