Manipulating the Brain

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Chapter 14

• Manipulating the Brain

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Electrical Activity in the Brain
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Electrical Activity at the Cellular Level
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Balance

• There are many neurotransmitters
• Some excite (depolarize)
• Some inhibit (hyperpolarize)
• Some go both ways depending on the receiving
  cell)
• A balance of excitation and inhibition

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Drugs

• Alter balance
• Beyond the limits of excitation is seizure
• Beyond the limits of inhibition is respiratory
  failure, cardiovascular collapse and death

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General Depressants

• Ethyl alcohol (the kind you drink, all others are
  poison)
• Barbiturates
• Anesthetics

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General Depressants

• Depress electrical activity
• Disrupt membranes and increase action of GABA (an
  inhibitory neurotransmitter)
• All electrically excitable cells are effected
• Nerves
• Muscles (heart, skeletal, smooth)
• Kidney

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Inhibition is more sensitive than excitation
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Barbiturates

• Sedatives and hypnotics
• Non-selective general depression of electrical
  activity
• Barbituric acid, pentobarbital, seconal,
  pentothal- How long they last

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Barbturate Uses

• Epilepsy many types
• Sleeping pills
• Side effects
• Tolerance- The more you take, the more you need
  to take to have the same effect
• Dependence- Adverse reaction to withdrawl

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Barbiturates Other Side Effects

• Liver increased metabolism of
• Barbiturates
• Steroids
• Fat soluble vitamines

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Ethyl Alcohol

• The kind you drink
• Brain
• Liver
• Cardiovascular
• Digestion

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Selective depression of electrical activity in
the brain

• Manipulation of specific neurotransmitter systems
• Increase inhibition
• Decrease excitation

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Benzodiazepines

• Aka. Librium, Valium
• Increase the effect of GABA on the receiving cell
• Inhibition within a level
• Reticular formation
• Hypothalamus
• Limbic system
• Cerebral cortex

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Benzodiazepines Uses

• Sleeping pills
• Less depression of medullary centers than
  barbiturates
• Some types of epilepsies
• Parkinsons disease
• Anti-anxiety

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Benzodiazipines Side Effects

• Drowsiness, fatigue, in coordination, dizziness,
  blurred vision, behavioral
• With alcohol lethal
• Tolerance
• Dependence

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Neurotransmitters Excitation and Inhibition
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Food Additives

• MDG (monosodium glutamate)
• Aspartame
• 40 aspartic acid
• 50 phenylalanine
• 10 methanol

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Glycine

• Strychnine glycine antagonist
• Exciting even to seizures

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Mixed Neurotransmitters

• Sometimes excitatory, sometimes inhibitory
• Depends on receiving cell
• Biogenic amines

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Phenylketonuria (PKU)
Synthesis of Biogenic Amines Neurotransmitters
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Biogenic Amines

• Adrenalin/noradrenalin
• Stress Responses
• Reward
• Arousal
• Mood
• Dopamine
• Motor control
• Social behavior
• Hypothalamic releasing factors

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Serotonin

• AKA 5-hydroxytryptamine
• Lining of digestive system
• Platlets
• Brain
• Mood
• Drives
• Thinking and perception
• Sleep and attention
• Hypothalamus

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Mechanism of Transmission
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Many Drugs

• Cross reactivity between receptors
• Subtypes of receptors
• Drugs
• Antagonists
• Agonists
• Block destruction
• Block re-uptake
• Cause release

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Speeds

• Amphetamine and derivatives
• Cocaine
• Both cause release and block re-uptake
• Acute stress response
• Euphoria, paranoia
• Extreme focus of attention
• Seizures

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Speeds Uses

• Attention deficit disorder (ADD)
• Diet Pills
• Recreation

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Speed and the Sympathetic Nervous System
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Depression

• What is it?
• Unipolar
• Bipolar (manic depression cycling)

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Antidepressants

• Hypothesis depression is caused by depletion of
  one or more of the biogenic amines in the limbic
  system

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Tricyclic Antidepressants

• Blocks recovery of noradrenalin and seratonin
• Causes build up of both
• Interferes with both sympathetic and
  parasympathetic control

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Monoamine Oxidase Inhibitors

• Block the enzymes that bread down monoamine
• Biogenic amines build up in nerves and leak out
• Monomines are in many places the besides
  brainalso in foods

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Prozac and Paxil

• Blocks the reuptake of serotonin which causes
  build up
• Adverse effects
• Headache
• Nausea
• Dry mouth
• Dizziness, tremors
• Sexual dysfunction
• Hallucinations, aggression (LSD)????????????

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Lithium

• Li.Na
• Limited range between efficacy and toxicity
• Kidney toxicity

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Mental Disorders

• Psychosis
• Schizophrenia
• Hypothesis serotonin deficiency in limbic system
• Psychotomimetic drugs (LSD)
• Dopamine excess????
• Parkinsons disease

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Drugs

• Phenothiazines
• Block dopamine and other biogenic amines
• Even out behavior, sedation
• Muscle tremors
• Lots of problems but makes them tractable

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Epilepsy

• Uncontrolled electrical activity in the brain
• Benzodiazopines, barbiturate
• Phenytoin (dilantin), Valproate Na channel
  blocker
• Ca channel blockers

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Xanthines

• Blocks the breakdown of the second messenger cAMP
• Caffeine, theobromine - food
• Theophylline - drug

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Nicotine

• Stimulates sympathetic response
• Attention
• Drug seeking behavior

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Cannabinoids

• AKA marijuana
• Cannabinoid receptors anandamide
• Receptors in immune system, cerebral cortex,
  limbic system, cerebellum
• Mood, sensations, awareness of sound and sight
• Stimulates hunger
• Stress response
• Reduces nausea, intraoccular pressure

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Balance

• Drugs alter the balances of the brain