Lecture 14: Channels & Transporters

Question 1

How are electrical signals transmitted across synapses, and what role do voltage-sensitive ion channels play in this process?

Answer 1

• Synapse
  ○ Conduction of AP
  
  • Electrical signal carried by both Na and K channels
    ○ Triggers excitation of the cell
    ○ Goes down to the synapse
  • Potassium flowing out of the cell repolarizes
  • Electrical currents are carried all the way down
    ○ Triggers calcium channels
  • Na, K and Ca channels are voltage sensitive channels carried by conduction of ions across cellular membrane
    ○ Influx of Ca into the cell -> vesicles fuse in to cellular membrane -> carries a neurotransmitter n Ach
    ○ Acetylcholine flows across then binds to the receptor on the other membrane
  • Reset by Na K pump