(Solved): 4. Label the diagrams: Summation Inhibitory postsynaptic potentials and excitatory postsynaptic pot ...

4. Label the diagrams: Summation Inhibitory postsynaptic potentials and excitatory postsynaptic potentials also summate with each other. When inhibitory potentials are added to excitatory potentials, they reduce the magnitude of the excitatory postsynaptic potentials. The closer a synapse is to the trigger zone or axon hillock, the greater the effectiveness of that synapse. 5. Will the postsynaptic neuron generate an action potential? Why or why not? IPSP 3 mV (a) EPSP +6 mV EPSP Summation +4 mV EPSP +4 mV EPSP +5 mV The Action Potential Neurons communicate over long distances by generating an action potential. The action potential is a large change in membrane potential from a resting value of about -70 millivolts to a peak of about +30 millivolts, and back to -70 millivolts again. The action potential results from a rapid change in the permeability of the neuronal membrane to sodium and potassium. The permeability changes as voltage-gated ion channels open and close. The action potential is generated at the axon hillock, where the density of voltage-gated sodium channels is greatest. The action potential begins when the summation of EPSPs and IPSPS is sufficient to open voltage-gated channels for sodium.