Chapter 13: Nervous System
David F. Russell
Why do we study the nervous systems of fish? While some investigators have a comparative perspective, others take advantage of special features of fish such as large neurons (e.g., the Mauthner cells), or homogeneous tissues (e.g., the electroplax organs), or unique sensory modalities (e.g., electroreception). This chapter reviews convenient methods of neurophysiology, neuroanatomy, and neurochemistry. The literature on the fish nervous system is reviewed in Fish Neurobiology, Fish Physiology, Traite de Zoologie, The Biology o f Lampreys, and The Biology o f Myxine, each a multi volume series.
The nervous system of fish can be studied in several ways: (1) chronically, via electrodes implanted in alert, freely behaving animals; (2) in vivo, the animal remaining alive, but restrained, anesthetized, paralyzed, and dissected to expose the nervous system; (3) in vitro, after part of the nervous system is excised but sustained for several hours in a saline bath; or (4) in tissue slices or as cells enzymatically dissociated from excised nervous tissue.