Conditioned place preference (CPP) continues to be one of the most popular models to
study the motivational effects of drugs and non‐drug treatments in experimental animals …

Drug addiction is a chronic brain disorder leading to complex adaptive changes within the
brain reward circuits that involve several neurotransmitters. One of the neurochemical …

Several recent reports have demonstrated sex differences in the behavioral and
neurochemical response to cocaine. However, it is not clear whether differences exist in …

Cocaine abuse is a serious health problem in many areas of the world, yet there are no
proven effective medications for the treatment of cocaine dependence. Preclinical studies …

Although drugs of abuse have different acute mechanisms of action, their brain pathways of
reward exhibit common functional effects upon both acute and chronic administration. Long …

Objective Previous studies demonstrated that the dynorphin/κ opioid system was up-
regulated upon repeated cocaine self-administration. In the present study, we tested the …

Opioid peptides and receptors are broadly expressed throughout peripheral and central
nervous systems and have been the subject of intense long-term investigations. Such …

The μ-opioid receptor (OPRM1) is expressed in brain regions implicated in reward and
locomotor processes. Reduced reward, not only from opiates, but also from several other …

The endogenous opioid system is largely expressed in the brain, and both endogenous
opioid peptides and receptors are present in areas associated with reward and motivation. It …

Associations formed between conditioned stimuli and drug reward are major contributors in
human drug addiction. To better understand the brain changes that accompany this process …