title: Do jellyfish have central nervous systems?
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.
authors: Department of Biology and Marine Biology, University of North Carolina Wilmington and Center for Marine Science, 5600 Marvin K. Moss Lane, Wilmington, NC 28409, USA.
authors: Richard A
authors: RA
authors: Satterlie
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002490:Central Nervous System / Q000033:anatomy & histology / Q000502:physiology; D003063:Cnidaria / Q000033:anatomy & histology* / Q000502:physiology; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure; D013550:Swimming / Q000502:physiology