What are the two effects a neurotransmitter may have on a postsynaptic cell? What are the two potentials that result from each of these effects? Describe why the sum of each potential is important for generating an action potential as well as the ways these potentials can be summed. Why do you think a single excitatory potential is insufficient to produce an action potential?

 

The potential is called inhibitory as the membrane potential is even farther from the excitation threshold than in the resting state. The two potentials that result from each of these effects are either excitatory postsynaptic potential or inhibitiory postsynaptic potential. When multiple excitatory postsynaptic potentials occur on a single patch of membrane, it causes greater membrane depolarization and raises the the possibility of postsynaptic cell to reach the threshold for firing an action potential. When equivalent EPSPs (positive) and IPSPs (negative) are summed, they could cancel each other out. The processing of electrical information produced by excitatory and inhibitory potentials requires balance between EPSPs and IPSPs. A single excitatory potential is insufficient to produce an action potential as it is not strong enough to initiate firing or trigger an action potential. Simultaneous firing of excitatory action potentials causes spatial summation which generates sufficient strength to depolarize the axon hillock to the excitation threshold.