Synaptic Transmission Exercises

Synaptictransmissionotesinjan09pics

1. There are Many to One (Pre-synaptic neuron to Post-synaptic neuron) 2. When the ‘kereta AP’ arrives at the nerve Terminal, neurotransmitters are released. 3. Both inhibitory neurotransmitter Or excitatory transmitter are released from pre-synaptic neuronS to the post-synaptic neuron (many to One) 4. How does the AP at the nerve terminal lead to neurotransmitter release from both inhibitory and excitatory pre-synaptic neurons? 5. The events/mechanism at the pre-synaptic nerve terminal are the Same at both the inhibitory and excitatory neurons. 6. At both Inh or Exc nerve terminals, there occurs calcium influx from the ECF via voltage–gated Ca channels. 7. The AP produces the membrane potential change that opens the Ca vgated channel. 8. The post synaptic membrane (membrane of the post synaptic neuron directly Under the pre-synaptic nerve terminal) has receptors for either the inhibitory or excitatory neurotransmitter 9. Remember the ‘many to One’ neuronal connections. 10. Thus on a single post synaptic neuron, there will be multiple presynaptic inputs of inhibitory (GABA, Gly) as well as excitatory (Ach Glu) neurotransmitters. 11. Inhibitory pre-synaptic neurons will make the post synaptic membrane less excitable (membrane potential is moved further away from the critical firing threshold; the membrane is said to be hyperpolarized with a more negative mp). 12. Excitatory neurons will make the post synaptic membrane more easily excitable (a depolarization effect is produced) and the membrane potential is moved nearer to the firing mp threshold. 13. How do the inhibitory or excitatory pre-synaptic neurons cause the specific spots of post –synaptic membrane to be hyperpolarized or depolarized respectively? 14. The inhibitory or excitatory neurons cause movement of different ions (positive or negative ions) and this produce either the hyperpolarization or depolarization effects. 15. It is important before going further to review the direction of the transmembrnae gradient for the major ions involved (Na +, K+, Cl- )

Ming’synapse09