Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA.
Rev Neurosci. 2009;20(5-6):405-27. doi: 10.1515/revneuro.2009.20.5-6.405.
Arousal states strongly influence behavioral decisions. In general, arousal promotes activity and enhances responsiveness to sensory stimuli. Earlier work has emphasized general, or nonspecific, effects of arousal on multiple classes of behaviors. However, contemporary work indicates that arousal has quite specific effects on behavior. Here we review studies of arousal-related circuitry in molluscan model systems. Neural substrates for both general and specific effects of arousal have been identified. Based on the scope of their actions, we can distinguish two major classes of arousal elements: localized versus general. Actions of localized arousal elements are often limited to one class of behavior, and may thereby mediate specific effects of arousal. In contrast, general arousal elements may influence multiple classes of behaviors, and mediate both specific and nonspecific effects of arousal. One common way in which general arousal elements influence multiple behaviors is by acting on localized arousal elements of distinct networks. Often, effects on distinct networks have different time courses that may facilitate formation of specific behavioral sequences. This review highlights prominent roles of serotonergic systems in arousal that are conserved in gastropod molluscs despite extreme diversification of body forms, diet and ecological niches. The studies also indicate that the serotonergic elements can act as either localized or general arousal elements. We discuss the implications of these findings across animals.
唤醒状态强烈影响行为决策。一般来说，唤醒会促进活动并增强对感觉刺激的反应。早期的工作强调了唤醒对多种行为的一般或非特异性影响。然而，当代的研究表明，唤醒对行为有相当具体的影响。在这里，我们回顾了在软体动物模型系统中与唤醒相关的神经回路的研究。已经确定了唤醒的一般和特定影响的神经基质。基于它们作用的范围，我们可以将唤醒元素分为两类：局部和全局。局部唤醒元素的作用通常仅限于一类行为，从而介导唤醒的特定影响。相比之下，全局唤醒元素可能影响多种行为，并介导唤醒的特定和非特定影响。全局唤醒元素影响多种行为的一种常见方式是通过作用于不同网络的局部唤醒元素。通常，对不同网络的影响具有不同的时间进程，这可能有助于形成特定的行为序列。这篇综述强调了 5-羟色胺能系统在唤醒中的突出作用，尽管腹足纲软体动物的身体形式、饮食和生态位发生了极端多样化，但这种作用在腹足纲软体动物中是保守的。这些研究还表明，5-羟色胺能元素可以作为局部或全局的唤醒元素。我们讨论了这些发现对动物的意义。
