組員 :Sam Wang 王煜豪 Pony Lien 連顥庭
Reward-- positive value of an internal physical state Incentive motivation Affect (Want) (Like) Incentive salience (Brain’s dopamine system) (Incentive salience)
Psychological reward Anatomy Modulation by drugs
modification of behavior sensory properties of rewards. more effective than punishment in enforcing positive behavior Ex:altruism
Dopamine mesolimbic pathway mesocortical pathway
Region near the base of the brain Inputs of the reward system Releasing Dopamine mesolimbic pathway Inhibitory neuron Dopamine releasing VTA neuron Cerebral neuron of reward pathway
stimulate (D1 Receptor) inhibit (D2 Receptor)
increase the dopamine release Arises psychological drug tolerance, sensitization. Psychological drug tolerance CREB protein delta FosB activating genes causes sensitization. intense cravings (associated with drug addiction) extend the peripheral cues of drug use
Impulsive, destructive behavior medication Can’t help taking medicine 3 major reasons to lead to drug addiction 1.Hyperactive incentive system 2.Uncomfortable withdrawal symptoms 3.Permanent change in incentive system
Most of drugs can lead to hyperactive incentive system. They act on Brain’s dopamine system directly, so they can make mesolimbic pathway more vigor
Tolerance:need more medicaine to reach the general level of joy. Withdrawal: the unpleasant effects of getting used to not taking a drug that they have become dependent on
Neural sensitization: dopamine nerve cells were activated easily by drugs.
obtained from the leaves of the coca plant stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic The decreased dopaminergic signaling after chronic cocaine use may contribute to depressive mood disorders and sensitize this important brain reward circuit to the reinforcing effects of cocaine
psychostimulant drug increased wakefulness and focus decreased fatigue and appetite vesicular level dopamine transporter DAT reverse tolerance sensitization to psychological locomotor-stimulating effects benzodiazepines Barbiturates
Cocaine binds directly to the DAT transporter, inhibiting reuptake with more efficacy than amphetamines which phosphorylate it causing internalization; instead primarily releasing DAT (which cocaine does not do) and only inhibiting its reuptake as a secondary, and much more minor, mode of action than cocaine and in another manner: from the opposite conformation/orientation to DAT.
Diamorphine from morphine 3-monoacetylmorphine 6- monoacetylmorphine μ-opioid agonists morphine 6-MAM a strong analgesic deacetylated
name from the Greek god of dreams Morpheus is a potent opiate analgesic medication Can be used as an analgesic to relieve can be taken orally, rectally, subcutaneously, intravenously, intrathecally or epidurally