Elliott C J H, Susswein A J
Department of Biology, University of York, York YO10 5YW, UK.
J Exp Biol. 2002 Apr;205(Pt 7):877-96. doi: 10.1242/jeb.205.7.877.
Over the last 30 years, many laboratories have examined, in parallel, the feeding behaviour of gastropod molluscs and the properties of the nervous system that give rise to this behaviour. Equal attention to both behavioural and neurobiological issues has provided deep insight into the functioning of the nervous system in generating and controlling behaviour. The conclusions derived from studies on gastropod feeding are generally consistent with those from other systems, but often provide more detailed information on the behavioural function of a particular property of the nervous system. A review of the literature on gastropod feeding illustrates a number of important messages. (i) Many of the herbivorous gastropods display similarities in behaviour that are reflected in corresponding similarities in neural anatomy, pharmacology and physiology. By contrast, the same aspects of the behaviour of different carnivorous species are quite variable, possibly because of their specialised prey-capture techniques. Nonetheless, some aspects of the neural control of feeding are preserved. (ii) Feeding in all species is flexible, with the behaviour and the physiology adapting to changes in the current environment and internal state and as a result of past experience. Flexibility arises via processes that may take place at many neural sites, and much of the modulation underlying behavioural flexibility is understood at a systems and at a cellular level. (iii) Neurones seem to have specific functions that are consistent with their endogenous properties and their synaptic connections, suggesting that individual neurones code specific pieces of information (i.e. they are 'grandmother cells'). However, the properties of a neurone can be extremely complex and can be understood only in the context of the complete neural circuit and the behaviour that it controls. In systems that are orders of magnitude more complex, it would be impossible to understand the functional properties of an individual neurone, even if it also coded specific information. (iv) Systems such as gastropod feeding may provide a model for understanding the functional properties of more complex systems.
在过去30年里，许多实验室同时对腹足纲软体动物的摄食行为以及产生这种行为的神经系统特性进行了研究。对行为学和神经生物学问题给予同等关注，使人们对神经系统在产生和控制行为方面的功能有了深入了解。从腹足纲动物摄食研究中得出的结论通常与其他系统的结论一致，但往往能提供关于神经系统特定特性行为功能的更详细信息。对腹足纲动物摄食文献的综述揭示了一些重要信息。（i）许多草食性腹足纲动物在行为上表现出相似性，这反映在神经解剖学、药理学和生理学的相应相似性上。相比之下，不同肉食性物种行为的相同方面差异很大，这可能是由于它们专门的捕食技巧。尽管如此，摄食的某些神经控制方面得以保留。（ii）所有物种的摄食行为都具有灵活性，行为和生理会根据当前环境和内部状态的变化以及过去的经验进行调整。灵活性通过可能在许多神经部位发生的过程产生，行为灵活性背后的许多调节在系统和细胞水平上已为人所知。（iii）神经元似乎具有与其内在特性和突触连接相一致的特定功能，这表明单个神经元编码特定的信息片段（即它们是“祖母细胞”）。然而，神经元的特性可能极其复杂，只有在完整神经回路及其所控制行为的背景下才能理解。在复杂程度高出几个数量级的系统中，即使单个神经元也编码特定信息，也不可能理解其功能特性。（iv）诸如腹足纲动物摄食这样的系统可能为理解更复杂系统的功能特性提供一个模型。
