The Brain, Nervous System,

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The Brain, Nervous System, Neurotransmission

• How drugs influence the brain, body behavior.

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What is a Drug?

• What does the substance do to the body?
• Psychoactive, physiological,
• Impairment Physical, psychological, social
• What is the intent of the use?
• Instrumental, Recreational
• Social Constructionism
• Good-Bad, Legal-Illegal, Accepted-Rejected

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Where do Drugs come From?

• Origins of Drugs are Organic / Natural
• Processing increases concentration.
• Pharmaceuticals are an example.
• Designer Drugs
• Non-naturally occurring substances. Target
  specific functions.

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Drug Delivery Methods

• Inhaling
• Fastest Route to Brain
• Injecting
• Mainlining Skin Popping
• Intra-muscular
• Absorption
• Nasal, Oral, Skin Patches
• Ingestion
• Eating Drinking
• Slowest Largest Quantity

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Inhalation

• VERY FAST - body needs O2
• 5-8 seconds from lungs to brain
• Burn, breathe in particles
• BUT other particles too
• Emphysema, asthma, lung cancer
• Exs nicotine, crack, THC(MJ), anesthetics,
  gasoline, glues

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Injecting

• Bypasses digestive system - more direct route to
  blood
• Intravenous (IV) - fastest 15 sec to brain
  (heroin) Rapid, intense, irreversible
• Intramuscular (IM) -arm, butt. Slower
  absorption.
• Ex measles, tetanus, flu shots
• Sub-cutaneous (Sub-Q) - needle into tissue under
  skin. Slower, skin gets irritated. Skin popping
• Disadvantage bacteria, virus spread

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Absorption

• Nasal - snuff, cocaine. Adheres to mucous
  membrane in nose, dissolved into blood
• Oral - chewing tobacco
• Rectum - rectal suppository
• Skin - patches. Nicotine, estrogen,
  motion-sickness

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Ingestion

• Eating and drinking
• Oldest method
• Slowest method - takes 5-30 min to be absorbed
• 6-8 hour grace period
• Acids absorbed better than bases
• Many barriers so need larger quantities

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Factors Influencing Effects

• Drug Combinations
• Additive
• (3 4 7)
• Potentiation
• (0 5 7)
• Synergism
• (5 5 15)
• Antagonistic
• (5 7 3)
• Toxic Reactions

• Quantity Concentration
• Size of Individual
• Gender
• Ethnicity
• Expectation Effects

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Dose Response Curves

• Effective Dose ED-1, ED-50, ED-99
• Lethal Dose LD-1, LD-50, LD-99
• Margin of Safety LD-1 / ED-99
• Therapeutic Index LD-50 / ED-50

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Organization of Nervous System
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Parasympathetic - Sympathetic
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Drug Action Through the Brain

• Of all the Chemical Compounds, Only about 30 are
  abused by Humans
• Drugs Achieve Effects Through Brain
• Drugs Reach the Brain through the Blood Supply
• All Drugs of Abuse Cross the Blood Brain Barrier

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Brain Anatomy
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Brain Regionalized Functions
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Brain Stem Anatomy
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Major Functions of Brain Stem

• Regulation of Homeostasis of Body Functions
• Refined Motor Control Posture
• Signal Processing
• Memory Formation
• Drive States
• Basic Emotions (Appetitive Defensive)

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Brain Stem Structures Functions

• Medulla
• Blood Pressure
• Breathing
• Heart Rate
• Body Temperature
• Digestion
• Vomit Reflex/Response

• Pons
• Sleep Patterns
• General Alertness

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Brain Stem Structures Functions

• Hypothalamus
• Survival Drives (Appetitive)
• Eating
• Drinking
• Sexual Behavior

• Limbic System
• Organization of Defensive Emotional Behavior
• Mood States

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Brain Stem Structures Functions

• Thalamus
• Signal Processing
• Coordination of Sensory Input - Relay
• Hippocampus
• Memory Formation
• Learning

• Substantia nigra
• Motor Control
• Tonic Body Posture
• Cerebellum
• Refined Coordination

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Organization of Cerebral Regions
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Cerebral Cortex
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Temporal Lobe

• New Learning (Hippocampus)
• Short-Term Memory
• Long-Term Memory

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Frontal Lobe

• Attention
• Concentration
• Problem Solving
• Judgment
• Emotionality

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Parietal Lobe

• Integration of Sensory Information
• Somatic Hallucinations
• Reality Distortion
• Delusions

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Occipital Lobe

• Visual Hallucinations
• Visual Perceptual Distortions

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The Neuron Key to Communication

• 100,000,000,000 Neurons
• Average Neuron has 10,000 Synapses (Connections)
• More than 200 types of Neural Cells

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Neural Cell Variations

• Key types of Neurons
• Signal Transmission
• Signal Interpretation

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Neural Cell Anatomy
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Signal Traveling Down Axon
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Axon Ion Channels
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Synaptic Transmission
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Neurotransmission Action

• General Function of Cell may be either
• Excitatory (sends signal)
• Inhibitory (stops signal)
• Effects of Neurotransmitter
• Stimulant Increases Function of Cell
• Depressant Decreases Function of Cell

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Basic Neurotransmitters

• Dopamine
• Motor Control
• Emotional Stability
• Craving (Reward)
• Serotonin
• Mood Levels
• Sleep Patterns
• GABA
• Inhibitory Control

• Acetylcholine
• Motor Activity
• Parasympathetic Sys
• Norepinephrine
• Hypothalamus Limbic System Concentration
• Endorphines
• Natural Painkillers

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Example of Drug Effects on Neurotransmitter Levels

• Treatments for Depression
• Serotonin Levels
• Tricyclic Drugs
• Directly Activate Targeted Receptor Sites
• SSRIs (Selective Serotonin Reuptake Inhibitors)
• Blocks mechanism reabsorbing neurotransmitter
  from source cell
• MAOIs (Monoamine Oxidase Inhibitors)
• Blocks enzymes from breaking down
  neurotransmitters in synaptic cleft.

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How Drugs Effect the Brain THC Binding Sites
Sensation
Judgment
Emotion Reward
Memory
Coordination
(hippocampus)
N.I.D.A