Biology of Substance Dependence

Behavioral neuroBiology

NeuroTransmitters involved in drug seeking behavior

Decreased Dopamine in Nuclus Accubuns

Decreased Serotonin in Nuclus Accumbuns

Serotonic 1B receptors ---) less sensitive so tolerance develops slowly

Biology of Reinforcement

Brain Stimulus Reward (BSR) system (MFB&VTA)Dopamine in VTA and NA mechanisms

direct on dopamine as in case of Cocaine and stimulants as Amphetamins

Through Glutamate as in NMDA antagonists --)prevents potentiation or sensitization

Stimulation of M receptors in VTA and NA (local disinhibition effect on dopamine

through 5 HT1A

through GABA --) BDZ

Biology of Relapse

Conditioning Model ---)Stimuli can elicit withdrawal

Homeostatic Neuroadaptive model (protracted abstinence theory)

--)liking effect is different from wanting effed

repeated exposure causes sensitization to the wanting effects