Conditioning method determines patterns of c-fos expression following novel taste-illness pairing

Behav Brain Res. 2006 Apr 25;169(1):93-7. doi: 10.1016/j.bbr.2005.12.006. Epub 2006 Jan 19.

Abstract

Conditioned taste aversions (CTAs) can be established by exposing rats to a novel taste CS through a bottle or through intra-oral (IO) infusion. Lesion studies suggest differences between the two methods in their engagement of brain circuits, as excitotoxic amygdala lesions have no effect on bottle-conditioned CTAs, but eliminate CTAs produced using IO infusion. Fos-like immunoreactivity (FLI) was used to compare patterns of brain activation after pairing CS taste and US drug using bottle and IO methods. Conditioning rats using the bottle method was associated with widespread elevations in FLI throughout the putative CTA circuit (basolateral and central nuclei of amygdala, insular cortex and nucleus of the solitary tract). In contrast, IO conditioning led to activation only in the central nucleus of amygdala. This supports the suggestion of differences in aversion processing as a function of conditioning method and may explain the greater reliance on amygdala of IO-conditioned CTAs due to engagement of a less distributed neural network.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Oral
  • Amygdala / metabolism
  • Animals
  • Association Learning / physiology
  • Avoidance Learning / drug effects
  • Avoidance Learning / physiology*
  • Behavioral Research / methods
  • Cerebral Cortex / metabolism
  • Conditioning, Psychological / physiology*
  • Drinking Behavior / drug effects
  • Drinking Behavior / physiology
  • Lithium Chloride / administration & dosage
  • Male
  • Neural Pathways / metabolism*
  • Proto-Oncogene Proteins c-fos / metabolism*
  • Rats
  • Rats, Long-Evans
  • Solitary Nucleus / metabolism
  • Taste / drug effects
  • Taste / physiology*
  • Tissue Distribution

Substances

  • Proto-Oncogene Proteins c-fos
  • Lithium Chloride