The rostromedial tegmental nucleus (RMTg), a GABAergic afferent to midbrain dopamine neurons, encodes aversive stimuli and inhibits motor responses.

ABSTRACT: Separate studies have implicated the lateral habenula (LHb) or amygdala-related regions in processing aversive stimuli, but their relationships to each other and to appetitive motivational systems are poorly understood. We show that neurons in the recently identified GABAergic rostromedial tegmental nucleus (RMTg), which receive a major LHb input, project heavily to midbrain dopamine neurons, and show phasic activations and/or Fos induction after aversive stimuli (footshocks, shock-predictive cues, food deprivation, or reward omission) and inhibitions after rewards or reward-predictive stimuli. RMTg lesions markedly reduce passive fear behaviors (freezing, open-arm avoidance) dependent on the extended amygdala, periaqueductal gray, or septum, all regions that project directly to the RMTg.

SUBMITTER: Jhou TC 

PROVIDER: S-EPMC2841475 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature