Neuronal analysis of pharyngeal peristalsis in the gastropod Navanax in terms of identified motoneurons innervating identified muscle bands. I. Muscle band identifiability

Mitchell S. Cappell, David C. Spray, Abraham J. Susswein, Michael V.L. Bennett

Research output: Contribution to journalArticle

3 Scopus citations


The neuronal basis of pharyngeal ingestion and swallowing can be conveniently studied in the marine mollusc Navanax inermis because of the small number of neurons involved in the behavior, reproducible identifiability of many individual neurons and simple muscle arrangement. The Navanax pharynx contains 3 approximately orthogonal muscle groups, circumferential, longitudinal and radial, arranged in well defined layers. Pharyngeal peristalsis involves sequential circumferential constriction, apparently with coordinated local pharyngeal expansion produced by radial muscle. Circumferential and longitudinal muscles consist of discrete, well defined bands. The number, position and arrangement of circumferential and longitudinal bands show little interanimal variability; these bands are individually identified by sequential number. Regional morphologic specializations of circumferential bands presumably facilitate peristalsis. Circumferential and longitudinal bands form a two dimensional reference system defining position on the pharyngeal surface. In the accompanying paper circumferential motor fields are described in terms of identified motoneurons innervating identified bands, and radial motor fields are located with respect to the coordinate system of overlying longitudinal and circumferential bands.

Original languageEnglish (US)
Pages (from-to)258-265
Number of pages8
JournalBrain Research
Issue number2
StatePublished - Nov 20 1989



  • Buccal ganglion
  • Enteric nervous system
  • Gastropod
  • Mollusc
  • Motoneuron
  • Navanax inermis
  • Peristalsis
  • Pharynx

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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