Initiation of impulse stas in

Several inhibitory synapses are located directly on the axon hillock and initial axon segment. This location provides especially powerful inhibition because it has the direct effect of increasing the threshold for excitation at the very point where the action potential is normally generated.Ref: Guyton; 13th edition; Chapter 46; Organization of the Nervous System, Basic Functions of Synapses, and Neurotransmitters