Stanley M. Crain

TL;DR: The findings that chronic morphine and cocaine produce similar adaptations in the NAc, a brain region important for the reinforcing actions of many types of abused substances, suggest further that common mechanisms may underlie psychological aspects of drug addiction mediated by this brain region.

TL;DR: The evidence for mediation of direct excitatory effects by naloxone-reversible opioid receptors is reviewed and it is proposed that this dual modulatory mechanism may help to account for previously unexplained enhancement by opioids of transmitter release, paradoxical hyperalgesic and aversive effects of opioids, and some aspects of opioid tolerance and addiction.

TL;DR: Clinical treatment of pain can be significantly improved by administering morphine or other conventional opioid analgesics together with appropriately low doses of an excitatory opioid receptor antagonist, according to preclinical studies in vitro and in vivo.

TL;DR: Cotreatment of mice with morphine plus ultra-low-dose NTX does, in fact, enhance the antinociceptive potency of morphine in tail-flick assays and attenuate development of withdrawal symptoms in chronic, as well as acute, physical dependence assays.

TL;DR: The data indicate that opioid-induced APD prolongation is not mediated by pertussis toxin-sensitive G proteins and suggest that elevation of cyclic AMP levels may enhance opioid excitatory responsiveness.