Arrange the events of synaptic transmission in the correct sequence. (1) sodium ions diffuse into the cell and cause a local potential (2) neurotransmitter binds with receptor on postsynaptic cell (3) neurotransmitter diffuses across the synaptic cleft (4) membrane permeability to sodium ions on postsynaptic cell increases (5) action potential causes release of neurotransmitter A. 5, 2, 3, 4, 1 B. 5, 2, 3, 1, 4 C. 5, 3, 4, 1, 2 D. 5, 4, 3, 2, 1 E. 5, 3, 2, 4, 1

The arrival of action potential usually causes influx of calcium ions at the pre-synaptic neuron. This leads to the migration of vesicles containing the neurotransmitters to the tip of the postsynaptic membranes and the release of their containing neurotransmitters into the synaptic cleft.

The neurotransmitter diffuses across the cleft, to bind with the post synaptic receptors on the membrane of post synaptic neuron. This increases the opening of Ligand gated sodium channels;leading to influx of sodium ions into the post synaptic neuron. This causes depolarization, and few sodium gated channels opened initially, but with time more channels open amusing the intensity is sustained .

Local potentials are generated due to influx of sodium ions, and if these potentials are summed together, and the voltage up to the threshold level 'it leads to generation of EPSPs Exicitatory Post-Synaptic Potentials or or IPSPs, depending on the type of neurotranmitters in the vessicles