Read page 424-425 on drugs and the brain

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Read page 424-425 on drugs and the brain

• What 3 major concepts should we study to
  understand this article further?

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Synapsesin-aps, si-napsSynapse

• (noun) Small gap between nerve cells
• Use in a sentence A synapse is cool.

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Neurotransmitters and The Synapse
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• Synapse unique junction that mediates
  information flow from one neuron to another or
  effector cell huh?

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• Most synapses occur between axon of one nerve and
  the dendrite of another BUT

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Pre vs Post

• Presynaptic neuron- carries impulse towards a
  synapse Sender
• Postsynaptic neuron- carries impulse away from a
  synapse receiver

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• TWO TYPES
• A. electrical synapse
• B. chemical synapse

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Electrical Synapse

• Allow current carrying ions to flow directly from
  one neuron to the next
• Found in the brain, limited in adulthood
• Most are replaced by chemical synapses

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Chemical Synapses

• -release/reception of neurotransmitters
• Neurotransmitters act to open/close ion channels

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Anatomy of the chemical synapse

• axonal
  terminal
• synaptic
  vesicles
• receptor region
• synaptic cleft

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Information Transfer Across Chemical Synapses

• 1. Calcium gates open in the presynaptic axonal
  terminal
• Depolarization causes voltage-gated Ca2 channels
  to open

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• 2. Neurotransmitter is released
• Direct result of calcium being present
• Exocytosis

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• 3. Neurotransmitter binds to post-synaptic
  receptors
• 4. Ion channels open in the post-synaptic
  membrane Boom!

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Neurotransmitters

• -language of the nervous system
• -50 known NT

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Classification

• 1. Acetylcholine (ACh)
• -first identified, best understood
• 2. Biogenic Amines
• Include dopamine, norepinephrine and
  epinephrine, histamine and serotonin

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• 3. Amino Acids
• 4. Peptides (neuropeptides)
• substance P, endorphins,
• 5. Novel Messengers
• ATP
• Nitric Oxide
• Carbon Monoxide

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Synthesis of Neurotransmitters