synapses

• How do nerve cells communicate with each other?

  Via a synapse

  
• What does the pre-synaptic neuron do?

  It sends information to the post-synaptic neuron

  
• What happens when an action potential reaches the axon terminal button?

  Synaptic vesicles release neurotransmitters

  
• How do neurotransmitters reach the post-synaptic neuron?

  They diffuse across the synaptic cleft

  
• What happens to neurotransmitters after they are released?

  Some bind to receptors, others are reabsorbed

  
• What is the effect of EPSP on a post-synaptic neuron?

  It makes the neuron more likely to fire

  
• What is the effect of IPSP on a post-synaptic neuron?

  It makes the neuron less likely to fire

  
• What is the structure and function of synapses?

  • Neurons communicate in groups called neural networks
  • Each neuron is separated by a synapse
  • Signals within neurons are electrical; between neurons, they are chemical

  
• How do vesicles release neurotransmitters?

  Through exocytosis into the synaptic cleft

  
• What happens to excess neurotransmitter in the synaptic cleft?

  It is taken up by the pre-synaptic neuron

  
• What is the role of enzymes in neurotransmission?

  To break down neurotransmitters
• What is required for a neurotransmitter to activate a receptor?

  It must be the correct neurotransmitter for the receptor
• What happens when the right neurotransmitter binds to the right receptor?

  An ion channel opens in the membrane
• What is the resting membrane potential of a post-synaptic neuron?

  -70 millivolts
• What is depolarization in a neuron?

  Becoming more positive, e.g., from -70 mV to -65 mV
• What is hyperpolarization in a neuron?

  Becoming more negative, making firing less likely
• What is the process of summation in neurons?

  Adding positive and negative potentials together
• What determines whether a post-synaptic neuron will fire?

  The summation of excitatory and inhibitory inputs

  
• What are the effects of excitation and inhibition on neurons?

  • Excitation: Increases positive charge (depolarization), makes firing more likely (EPSP)
  • Inhibition: Increases negative charge (hyperpolarization), makes firing less likely (IPSP)

  
• How do neurons communicate electrochemically?

  Through action potentials and neurotransmitters

  
• What happens to the membrane potential when a neuron is at rest?

  It rests at -70 millivolts
• What causes the membrane potential to change?

  Inputs from other neurons' axons
• What is the role of neurotransmitters in synaptic transmission?

  They assist in transferring impulses across synapses

  
• What is the significance of the synaptic gap?

  It separates pre-synaptic and post-synaptic neurons

  
• What is the function of synaptic vesicles?

  To store and release neurotransmitters

  
• What is the process of exocytosis in neurotransmission?

  Release of neurotransmitters from vesicles

  
• What happens to neurotransmitters after they bind to receptors?

  They can cause depolarization or hyperpolarization
• What is the role of receptor sites in neurotransmission?

  They recognize and activate specific neurotransmitters
• What is the effect of an excitatory neurotransmitter?

  It increases the likelihood of neuron firing
• What is the effect of an inhibitory neurotransmitter?

  It decreases the likelihood of neuron firing
• What is the significance of the summation of EPSPs and IPSPs?

  It determines if the neuron will fire

  
• What happens during the process of re-uptake?

  The neurotransmitter is taken back by the pre-synaptic neuron

  
• What is the role of ions in neuronal signaling?

  They create electrical signals in neurons
• What is the effect of depolarization on a neuron?

  It makes the neuron more likely to fire
• What is the effect of hyperpolarization on a neuron?

  It makes the neuron less likely to fire
• What is the relationship between action potentials and neurotransmitters?

  Action potentials trigger neurotransmitter release

  
• What is the role of the synaptic cleft in neurotransmission?

  It is the gap neurotransmitters cross

  
• What happens to the membrane potential during excitation?

  It becomes more positive
• What happens to the membrane potential during inhibition?

  It becomes more negative
• What is the significance of neurotransmitter specificity?

  Only certain neurotransmitters activate specific receptors