Neurotransmitters

• Neurotransmitters can be what?


  Excitatory, inhibitory or both
• What do excitatory neurotransmitters do?


  DEPOLARISE the postsynaptic membrane, making it fire an AP if the THRESHOLD is reached
• Example of excitatory neurotransmitter?


  Ach is an excitatory neurotransmitter at cholinergic synapses in the CNS - it binds to cholinergic receptors to cause an AP in the postsynaptic membrane - and at neuromuscular junctions
• What do inhibitory neurotransmitters do?


  HYPERPOLARISE the postsynaptic membrane, PREVENTING it from firing an AP
• what does it mean if the postsynaptic membrane is hyperpolarised?


  the potential difference is made more negative
• Example of inhibitory neurotransmitter?


  Ach is an inhibitory neurotransmitter at cholinergic synapses in the HEART . when it binds to potassium ions here, it can cause potassium ion channels to open on the postsynaptic membrane, hyperpolarising it