Mouse anti-Morphine monoclonal antibody for LFIA. Morphine is thought toproduce reinforcement phenomena via stimulation of mu, delta, and kappaopioid receptors that regulate stress perception, pain control, rewardbehavior, and neurohormone secretion in reward-relevant brain systems. It hasthe highest affinity for mu, followed by delta and kappa. Rapid activation ofthe mu opioid receptor by morphine results in a euphoric phenotype, thusconferring the reinforcing effects of the drug. This activation isaccompanied by extracellular dopamine release, which alters several eventsrelated to the cAMP signal transduction pathway. Of particular significanceis that CREB seems to be modified by morphine, thereby affecting addictivebehavioral phenomena, such as withdrawal symptoms.