A Key Role of the Mammillary Body in Mediation of the Antianxiety Action of Zopiclone, a Cyclopyrrolone Derivative

Abstract

The present study was designed to elucidate the brain site of the anticonflict action of zopiclone (ZOP), a cyclopyrrolone derivative, using the rat conflict procedure. ZOP at 10 μg/μl, bilaterally injected into the mammillary body (MB), produced a significant increase in the punished responses, with no change in the unpunished responses. There were no significant changes in these responses when ZOP was injected into the central amygdala, frontal cortex or dorsal hippocampus. Attention should be given to the possibility that the MB is the site of the anticonflict action of ZOP.