OPIOID-PEPTIDES IN AMPHIBIA

In this work we present information about the identification of opioid peptides and receptors in the nervous system and other tissues of amp hibians. Evidences about the possible participation of opioid systems in the amphibians physiology are included. The importance of the studi es of opioids in amphibians is considered in relation to significance of these animals in the evolution of vertebrates, and their utility as a study model for opioids due to their simplicity and plasticity, par ticularly in the development and nociception process.