Selective enhancement of emotional, but not motor, learning in monoamine oxidase A-deficient mice

Jeansok J. Kim, Jean C. Shih, Kevin Chen, Lu Chen, Shaowen Bao, Stephen Maren, Stephan G. Anagnostaras, Michael S. Fanselow, Edward De Maeyer, Isabelle Seif, Richard F. Thompson

Research output: Contribution to journalArticlepeer-review

133 Scopus citations


Mice deficient in monoamine oxidase A (MAOA), an enzyme that metabolizes monoamines such as norepinephrine and serotonin, have elevated norepinephrine and serotonin levels in the frontal cortex, hippocampus, and cerebellum, compared with normal wild-type mice. Since monoamines in these areas are critically involved in a variety of behaviors, we examined learning and memory (using emotional and motor tasks) in MAOA mutant mice. The MAOA- deficient mice exhibited significantly enhanced classical fear conditioning (freezing to both tone and contextual stimuli) and step-down inhibitory avoidance learning. In contrast, eyeblink conditioning was normal in these mutant mice. The female MAOA-deficient mice also displayed normal species- typical maternal behaviors (nesting, nursing, and pup retrieval). These results suggest that chronic elevations of monoamines, due to a deletion of the gene encoding MAOA, lead to selective alterations in emotional behavior.

Original languageEnglish (US)
Pages (from-to)5929-5933
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number11
StatePublished - May 27 1997
Externally publishedYes


  • Amygdala
  • Cerebellum
  • Mutant mice
  • Norepinephrine
  • Serotonin

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Selective enhancement of emotional, but not motor, learning in monoamine oxidase A-deficient mice'. Together they form a unique fingerprint.

Cite this