Opioids are substances derived from opium (natural opioids). In its raw state, opium is a
gummy latex extracted from Papaver somniferum. The use of opioids and their negative …

Abstract Alcohol Use Disorder is a complex genetic disorder, involving genetic, neural, and
environmental factors, and their interactions. The Collaborative Study on the Genetics of …

This paper is the forty-second consecutive installment of the annual anthological review of
research concerning the endogenous opioid system, summarizing articles published during …

Background: Pavlovian-to-instrumental transfer (PIT) quantifies the extent to which a
stimulus that has been associated with reward or punishment alters operant behaviour. In …

Morphine has a strong analgesic effect and is suitable for various types of pain, so it is
widely used. But long-term usage of morphine can lead to drug tolerance, which limits its …

Background Efforts to understand genetic variability involved in an individual's susceptibility
to chronic pain support a role for upstream regulation by epigenetic mechanisms. Methods …

Opioid use disorder is a chronic, relapsing disease associated with persistent changes in
brain plasticity. A common single nucleotide polymorphism (SNP) in the µ-opioid receptor …

Chronic pain often develops severe mood changes such as depression. However, how
chronic pain leads to depression remains elusive and the mechanisms determining …

Genetic variants in the opioid receptor mu 1 (OPRM1) and dopamine receptor d2 (DRD2)
genes are implicated in behavioral phenotypes related to substance use disorders (SUD) …

Mu-opioid receptors (MORs) mediate the rewarding properties of oxycodone and other
prescription opioid medications, which have played a central role in the current opioid …