Somatosensory evoked potentials in the telencephalon of Atlantic salmon (Salmo salar) following galvanic stimulation of the tail

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2007 Dec;193(12):1235-42. doi: 10.1007/s00359-007-0283-1. Epub 2007 Nov 7.

Abstract

Electric activity in the brain which is time-locked to a given stimulation of the somatosensory system can be recorded as a somatosensory evoked potential (SEP). We investigated whether a galvanic stimulation of the tail base in Atlantic salmon (Salmo salar) would elicit a SEP in the telencephalon. The telencephalon is central in learning and memory, and activity here may be a prerequisite for processing of external stimuli on a cognitive or emotional level. Anaesthetized salmon (n = 11) were subjected to craniotomy and a recording electrode was inserted into the telencephalon. The fish were given stimulations of four intensities, i.e., 2, 5, 10 and 20 mA. A SEP was elicited in the contralateral dorsal telencephalon for all intensities. This result agrees with findings in other fish species. Furthermore, there was a significant difference between the maximum peak amplitude and mean amplitude of the SEP elicited by putative non-noxious (2 mA) and putative noxious (20 mA) stimulation intensities (P < 0.01). The stronger stimulation intensities also tend to introduce longer-latencies components in the SEP. The results added to the body of literature indicates that the exteroceptive senses are represented by processing within the telencephalon of the fish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology
  • Dose-Response Relationship, Radiation
  • Electric Stimulation / methods
  • Evoked Potentials, Somatosensory / physiology*
  • Galvanic Skin Response / physiology*
  • Salmon / anatomy & histology*
  • Salmon / physiology
  • Tail / innervation*
  • Telencephalon / physiology*