Brain Chemistry Basics'''

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Brain Chemistry Basics...
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Brain Anatomy

• The brain can be divided into three basic units
• Hindbrain Midbrain Forebrain

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What does this all mean?

• In the forebrain emotions and reward sensations
  are controlled
• Addiction
• Instinct
• Survival

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The Synapse and Neuron

• Gaps between nerve cells (neurons) are called
  synapses.
• Neurotransmitters (chemicals) are released into
  the synapse
• Receptors receive the neurotransmitters and
  activate the neuron

MAO enzyme that breaks down neurotransmitters
receptor
Neuron 1
Neuron 2
SYNAPSE
Vesicle (releases neurotransmitter)
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In summary

• 1. Vesicle RELEASES neurotransmitter into synapse
• 2. REUPTAKE of excess neurotransmitters
• 3. BREAK DOWN excess neurotransmitters

Activation energy barrier
energy
With MAO
dopamine
Broken down dopamine
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Neurotransmitters

• Neurons are on and off switches activated by
  neurotransmitters
• There are over 100 neurotransmitters...we will
  focus on four
• Serotonin
• Dopamine
• Epinephrine
• Acetylcholine

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Serotonin

• Provides feeling of confidence
• Low serotonin anxiety, depression
• High serotonin recklessness, belligerence
• Ecstasy (decreased serotonin) this drug has
  been shown to cause permanent damage to neurons
  after only one use.

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Dopamine

• Pleasure, reward cycle
• Low dopamine incorrect perceptions, Parkinsons
• High dopamine schizophrenia
• Cocaine, amphetamines, and many other drugs
  interfere with dopamine

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Epinephrine (Norepinephrine)

• Safety, danger
• Early in metabolic pathway to adrenaline, fight
  or flight
• Amphetamines, Hallucinogenic drugs mimic or
  interfere with norepinephrine

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Acetylcholine

• Memory
• Stimulates muscles and glands
• Discharge of sweat, tears, etc.
• Necessary for Addiction
• Nicotine affects acetylcholine receptors

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What Is Addiction?

• Addiction substance dependence
• Psychological craving
• Physical symptoms of withdrawl (body aches,
  shaking, flu-like symptoms, etc.)
• Neurotransmitters are disrupted, either directly
  or indirectly
• Dopamine involved in all addictive
  behaviors/addictions to drugs.
• Many addictions involve more than one
  neurotransmitter

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Mechanisms of Addiction

• Nicotine acts directly and indirectly
• It binds to acetylcholine receptors (direct)
• Disrupts dopamine transport (indirect)
• Cocaine acts indirectly
• It prevents dopamine reuptake by binding to the
  reuptake pump
• This results in increased production of dopamine,
  and increased number of dopamine receptors and
  increased sensitivity