Opioids mediate their effects via opioid receptors: mu, delta, and kappa. At the neuronal
level, opioid receptors are generally inhibitory, presynaptically reducing neurotransmitter …

The use of opioid analgesics has a long history in clinical settings, although the
comprehensive action of opioid receptors is still less understood. Nonetheless, recent …

Opioids are the most commonly used and effective analgesic treatments for severe pain, but
they have recently come under scrutiny owing to epidemic levels of abuse and overdose …

Drug addiction is a worldwide societal problem and public health burden, and results from
recreational drug use that develops into a complex brain disorder. The opioid system, one of …

By sustained activation of μ-opioid receptors (MORs), chronic opioids cause analgesic
tolerance, physical dependence, and opioid addiction, common clinical problems for which …

Decades of research advances have established a central role for endogenous opioid
systems in regulating reward processing, mood, motivation, learning and memory …

The cloning of the opioid receptors has profoundly affected our understanding of opioid-
receptor expression, regulation and function. This review focuses on the impact that cloning …

Opioids classically regulate the excitability of neurons by suppressing synaptic GABA
release from inhibitory neurons. Here, we report a role for opioids in modulating excitatory …

Opioids remain among the most effective pain-relieving therapeutics. However, their long-
term use is limited due to the development of tolerance and potential for addiction. For many …

Three major types of opioid receptors, designated μ, δ, and κ, are widely expressed in the
CNS. Development of selective receptor ligands and recent cloning of each receptor have …