Effects of discrimination learning on the rat amygdala dopamine release: a microdialysis study

Brain Res. 1993 Sep 10;621(2):296-300. doi: 10.1016/0006-8993(93)90119-8.


Extracellular levels of dopamine (DA) and its metabolites were monitored with the in vivo microdialysis method in the amygdala of rats while and after they performed a discrimination learning task or a non-discrimination task. A group of rats was trained to discriminate between lamp-on and lamp-off states under an operant-type learning procedure. After a stable discriminative behavior was established, a dialysis probe was inserted into the basolateral amygdaloid nucleus of each rat. The concentrations of DA and its metabolite 3,4-dihydroxyphenylacetic acid significantly increased during the learning sessions as compared to their basal levels. In contrast, another group of rats trained on a similar, but non-discriminative task showed no such increases. These results suggest that the dopaminergic neural systems in the basolateral amygdaloid nucleus are activated during ongoing behavior maintained under the discrimination learning situation.

MeSH terms

  • Amygdala / metabolism*
  • Animals
  • Discrimination Learning / physiology*
  • Dopamine / metabolism*
  • Male
  • Microdialysis
  • Rats
  • Rats, Inbred F344


  • Dopamine