Anatomy ch 7.3

• Neurotransmitters are stored in synaptic know vehicles and release by exocytosis
• Acetylcholine is an exciting or inhibitory depending on the organ
• Acetylcholine leaves the cleft and is recieved by acetylcholinesterase and broken into acetate and choline which are taken by the synaptic know once more
• 2 types of acetylcholine:

  Nicotinic receptor is ligand gatted

  Muscarinic receptor is g protein coupled
• In nicotinic receptors, acetylcholine binds and lets more sodium in than potassium out leading to ecotatory reaction. Acetylcholine is them broken down and recycled
• In PNS, motor neuron form interactions called neuromuscular junctions.

  ESPS formed here are called end plate potentials
• In G protein coupled channels, G protein is used to bind at the receptors to open ion channels
• Muscaranic acetylcholine receptors contain G protein, alpha, beta, and Gama subunits
• In muscarinic acetylcholine receptor:

  1. The binding of acetylcholine will cause alpha or bets and Gama will sepperate.
  2. Alpha or gamma and beta subunits will bund to ion channel
  3. Causes opening or close of ion channels
  4. Subunits is released and returns to the G protein
• In the heart, acetylcholine binds to g protein and releases beta and gama subunits. Beta and Gama will bind to channel and release alot of potassium ions
• Curare blocks nicotinic acetylcholine receptors as a result muscles cant contract which leads to paralysis and death
• Atropine is a muscarinic antagonist that blocks the effects of acytylcholine whicj speeds up heart rate
• Tetrodotoxin binds to voltage gated sodium channels causing it to no be able to depolarize a prodive action potential
• Local anesthetics block voltage gated sodium channels and prevents the formation of action potential
• There are two types of monoamines which are catecholamines (dopamin, norepinephrine, and epinephrine) and seratonin
• Monoamines after being used are taken into presyneptic cell (reuptake) and degraded bt monoamine oxidase or MAO
• Cyclic adenaine monophosphatre (cAMP) is most common second messanger for Catecholamine
• In monoamine action, monoamine does not bind to receptor but instead uses intermediate transmitter. The binding catecholine binds to receptor and causes G protein to disassociate and sends alpha unit to adequate cyclase which converted ATP to cAMP.

  cAMP and protein ligase inactin activates kinase which phosporylates other proteins which causes ion channels to open
• Norepinephrine found in the PNS and CNS are used in sympathetic neurons in autonomic sydtem
• Nigrostrial dopamine system is involved in motor control
• Mesolimboc dopamine system is involved in emotional award
• Seratonin is associated with behavior and mood. SSRIs is used to inhibit the reuptake of seratonin to remain the flow to treat depression
• Gamma- aminobutyric acid or GABA is most common neurotransmitter in the brain that acts as an inhibitory by opening Chlorine channels when it binds to receptor causing the cell to be hyperpolarized
• Glysine acts as inhibitory in spinal cord to control movement