In a neuron, graded electrogenesis occurs at:
Graded electrogenesis is local potential generation of which occurs in dendrite or, soma.
Neurons generally have some important zones: 

A receptor, or dendritic zone, where multiple local potential generated by synaptic connections are integrated;
A site where propagated action potentials are generated (the initial segment in spinal motor neurons, the initial node of Ranvier in cutaneous sensory neurons).
Soma-dendritic zone
Initial segment
Axon
Nerve ending