<p>Nerve nets—characterised by scattered neurons and mesh-like projections—represent a widespread organisation of nervous tissue. Nerve nets have uniquely diffuse conductivity and an apparent simplicity that features in many theories on the evolution of nervous systems. Here we review the anatomical and functional organisation of nerve nets and revisit evolutionary theories in light of new information. We discuss how transgenesis and volume electron microscopy begin to reveal the fine-scale cellular organisation of nerve nets. On the functional level, we describe how excitation can spread within nerve nets and how non-synaptic volume transmission enable multi-layered signalling, driving complex behaviours. As a convergent solution to tissue-scale coordination, we introduce ctenophores, where syncytial nerve nets implement distributed control. We argue that nerve nets are not primitive remnants in some animals or only historical preludes but represent an enduring organisational principle for animal coordination with many unique advantages.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Revisiting nerve nets: functional organization and evolutionary implications

  • Kei Jokura,
  • Gáspár Jékely

摘要

Nerve nets—characterised by scattered neurons and mesh-like projections—represent a widespread organisation of nervous tissue. Nerve nets have uniquely diffuse conductivity and an apparent simplicity that features in many theories on the evolution of nervous systems. Here we review the anatomical and functional organisation of nerve nets and revisit evolutionary theories in light of new information. We discuss how transgenesis and volume electron microscopy begin to reveal the fine-scale cellular organisation of nerve nets. On the functional level, we describe how excitation can spread within nerve nets and how non-synaptic volume transmission enable multi-layered signalling, driving complex behaviours. As a convergent solution to tissue-scale coordination, we introduce ctenophores, where syncytial nerve nets implement distributed control. We argue that nerve nets are not primitive remnants in some animals or only historical preludes but represent an enduring organisational principle for animal coordination with many unique advantages.