Synaptic transmission

• How long does synaptic transmission take?

  A fraction of a second
• What are the steps of synaptic transmission?

  1. Electrical impulse arrives at presynaptic neuron
  2. Synaptic vesicles release neurotransmitters
  3. Neurotransmitters diffuse into synapse
  4. Bind with receptors on postsynaptic neuron
  5. Cause excitatory or inhibitory response
  6. Reuptake of neurotransmitters into presynaptic neuron
• 1. Electrical Impulse Arrives at Presynaptic Neuron


  The action potential reaches the synaptic terminal of the presynaptic neuron, triggering the release of neurotransmitters.
• 1. Synaptic Vesicles Release Neurotransmitters


  The synaptic vesicles fuse with the plasma membrane and release neurotransmitters into the synapse.
• 1. Neurotransmitters Diffuse into Synapse


  The released neurotransmitters diffuse across the synapse, moving away from the presynaptic neuron.
• 1. Bind with Receptors on Postsynaptic Neuron


  The released neurotransmitters bind with specific receptors on the postsynaptic neuron, causing a change in its membrane potential.
• 1. Cause Excitatory or Inhibitory Response

  Depending on the type of neurotransmitter and receptor, this binding can have an excitatory or inhibitory effect on the postsynaptic neuron.
• 1. Reuptake of Neurotransmitters into Presynaptic Neuron


  The neurotransmitters are either broken down by enzymes or taken back up into the presynaptic neuron via reuptake, regulating the amount of neurotransmitters in the synapse.
• What type of signals are transmitted within neurons?

  Electrically
• What happens to neurotransmitters after they diffuse into the synapse?

  They bind with receptors on the postsynaptic neuron
• What do neurotransmitters do after being released into the synaptic gap?

  They diffuse and bind with receptors on the postsynaptic neuron
• How are signals transmitted between neurons?

  Chemically via synaptic transmission
• How long does synaptic transmission take?

  A fraction of a second
• What happens to neurotransmitters during reuptake?

  They are stored again in vesicles
• What determines whether the response in the postsynaptic neuron is excitatory or inhibitory?

  The type of neurotransmitter involved
• What is the process called when neurotransmitters are taken back into the presynaptic neuron?

  Reuptake
• What arrives at the presynaptic neuron during synaptic transmission?

  An electrical impulse (action potential)
• What type of neurotransmitter is dopamine?

  Excitatory neurotransmitter
• What effect does dopamine have on the receiving neuron?

  The neuron is more likely to fire
• How does dopamine affect our feelings when in balance?

  It makes us feel good, motivated, and focused
• What type of neurotransmitter is serotonin?

  Inhibitory neurotransmitter
• What effect does serotonin have on the receiving neuron?

  The neuron is less likely to fire
• How does serotonin affect our mood when at the right level?

  We feel calm, happier, and balanced
• What are the roles of dopamine and serotonin in the brain?

  • Dopamine:
  • Excitatory neurotransmitter
  • Increases likelihood of neuron firing
  • Promotes feelings of motivation and focus
  • Serotonin:
  • Inhibitory neurotransmitter
  • Decreases likelihood of neuron firing
  • Promotes feelings of calmness and happiness