Ionic and neuromodulatory regulation of burst discharge controls frequency tuning

J Physiol Paris. 2008 Jul-Nov;102(4-6):195-208. doi: 10.1016/j.jphysparis.2008.10.019. Epub 2008 Oct 18.

Abstract

Sensory neurons encode natural stimuli by changes in firing rate or by generating specific firing patterns, such as bursts. Many neural computations rely on the fact that neurons can be tuned to specific stimulus frequencies. It is thus important to understand the mechanisms underlying frequency tuning. In the electrosensory system of the weakly electric fish, Apteronotus leptorhynchus, the primary processing of behaviourally relevant sensory signals occurs in pyramidal neurons of the electrosensory lateral line lobe (ELL). These cells encode low frequency prey stimuli with bursts of spikes and high frequency communication signals with single spikes. We describe here how bursting in pyramidal neurons can be regulated by intrinsic conductances in a cell subtype specific fashion across the sensory maps found within the ELL, thereby regulating their frequency tuning. Further, the neuromodulatory regulation of such conductances within individual cells and the consequences to frequency tuning are highlighted. Such alterations in the tuning of the pyramidal neurons may allow weakly electric fish to preferentially select for certain stimuli under various behaviourally relevant circumstances.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Action Potentials / drug effects*
  • Action Potentials / physiology*
  • Animals
  • Biophysical Phenomena
  • Electric Fish / physiology
  • Electric Stimulation / methods
  • In Vitro Techniques
  • Ion Channels / physiology*
  • Models, Neurological
  • Neurotransmitter Agents / pharmacology*
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology
  • Rhombencephalon / cytology
  • Rhombencephalon / physiology
  • Time Factors

Substances

  • Ion Channels
  • Neurotransmitter Agents