Neurotransmitters and Drugs of Abuse

Glutamate

A major excitatory neurotransmitter; involved in memory

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system. Involved in Substantia Nigra / Ventral Tegmental Area: Dopaminergic neurons project to frontal lobe, amygdala, striatum (basal ganglia) Movement (Nigro-striatal pathway) Reward (Meso-limbic pathway)

Norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation Involved in: Central Nervous System, Peripheral Nervous System Half of all Norepinephrine — in Locus Ceruleus (reticular formation). Projects to Cerebral Cortex, Amygdala, Hippocampus, Cerebellum

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction Involved in Midbrain/Striatum

Ecstacy

A synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition. Affects: Neocortex, Basal Ganglia, Amygdala, Hypothalamus, Hippocampus, Serotonin Nerve Pathways

Serotonin

Affects mood, hunger, sleep and arousal. Undersupply linked to depression. Involved in midline of Hindbrain — projected to medial forebrain bundle, amygdala, hippocampal formation, spinal cord

Olds and Milner

Demonstrated existence of pleasure center in the brain using "self-stimulation" studies in rats Rats received direct electrical stimulation to median forebrain bundle — 7200 bar presses in 12 hours, preferred to food/water/sex/care of pups, continued desire punishment

Depressants

Drugs (such as alcohol, barbiturates, and opiates) that reduce the ability of the Central Nervous System Causes physical or psychological dependence

Narcotics/Opiates

Highly addictive drugs derived from opium that relieve pain Artificially flood brain's endorphin receptors — reducing their effectiveness/depressing their natural production of endorphins over time Binds to: Reward Pathway (Cerebral Cortex, Ventral Tegmental Area, Nucleus Accumbens) Pain Pathway (Thalamus, Brainstem, Spinal Cord)

Marijuana

Leaves and buds contain psychoactive drug THC Receptors that respond to THC — normally activated by Neurotransmitter anandamide (a Neurotransmitter that regulates mood, memory, appetite, and pain perception) Binds to: Ventral Tegmental Area, Nucleus Accumbens, Caudate Nucleus, Hippocampus, Cerebellum

GABA

Neurotransmitter: inhibits transmission of neural impulses

Stimulants

Substances that excite the central nervous system, heightening arousal and activity levels Increase levels of Dopamine/Norepinephrine in brain Binds to: Ventral Tegmental Area, Nucleus Accumbens, Caudate Nucleus