Do jellyfish have central nervous systems?

J Exp Biol. 2011 Apr 15;214(Pt 8):1215-23. doi: 10.1242/jeb.043687.

Abstract

The traditional view of the cnidarian nervous system is of a diffuse nerve net that functions as both a conducting and an integrating system; this is considered an indicator of a primitive condition. Yet, in medusoid members, varying degrees of nerve net compression and neuronal condensation into ganglion-like structures represent more centralized integrating centers. In some jellyfish, this relegates nerve nets to motor distribution systems. The neuronal condensation follows a precept of neuronal organization of higher animals with a relatively close association with the development and elaboration of sensory structures. Nerve nets still represent an efficient system for diffuse, non-directional activation of broad, two-dimensional effector sheets, as required by the radial, non-cephalized body construction. However, in most jellyfish, an argument can be made for the presence of centralized nervous systems that interact with the more diffuse nerve nets.

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Central Nervous System / anatomy & histology
  • Central Nervous System / physiology
  • Cnidaria / anatomy & histology*
  • Cnidaria / physiology
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology
  • Neurons / physiology
  • Neurons / ultrastructure
  • Swimming / physiology