Gabapentin modifies extracellular opioid peptide content in amygdala: a microdialysis study

Opioid peptide release was monitored in the amygdala and hippocampus of fre ely moving rats following a single oral administration of gabapentin using microdialysis. Extracellular opioid peptide levels were elevated above basa l levels in the amygdala within the first 60 (54%) and 90 min (68%) after g abapentin administration. Levels returned to basal conditions 120 min follo wing the treatment. No significant changes were detected in the hippocampus . The majority of immunoreactive material recovered from the amygdala follo wing gabapentin administration was identified as Leu-enkephalin and Met-enk ephalin by high performance liquid chromatography (HPLC) analysis. It is pr oposed that the enhanced opioid peptide release in the amygdala induced by gabapentin might be involved with the antiepileptic effects as well as with some adverse events produced by this drug. (C) 1999 Elsevier Science B.V. All rights reserved.