PSY 3142 Lecture Notes - Lecture 14: Naltrexone, Partial Agonist, Nalmefene

• School: University of Ottawa
• Department: Psychology
• Course: PSY 3142
• Professor: Philip Wall

Document Summary

Animal models are used to determine which areas of the brain are involved in withdrawal signs by injection opioid antagonists into speci c brain areas of dependent animals. Locus coreleus and pag are particularly sensitive to the antagonist. The acc in the limbic system is important reinforcement and may be important in the aversive stimulus e ects or motivational aspects of opiod withdrawal. Animal injected with an antagonists (producing withdrawal) in a novel location will develop an aversion of the novel location. Himmelsbach (1943): classic hypothesis of opioid tolerance and dependence. The nervous system adapts to the disturbing presence of a drug and tolerance develops. If the drug is withdrawn, the adaptive mechanism continues to function, causing rebound physiological e ects. 1970s: cell cultures provided a physiological correlate for the classic hypothesis of tolerance and dependence. Morphine cause inhibition of adenylyl cyclase, the enzyme that manufactures camp. After two days of morphine he cells adapted by producing more camp.