A commonly pursued goal in studying synaptic plasticity is to determine whether synaptic inputs undergo presynaptic and/or postsynaptic alterations following a stimulus and how these alterations affect the firing properties of the innervated neuron. In this chapter we continue to discuss approaches that can be implemented to test presynaptic mechanisms of plasticity. In addition, we explain modifications that can occur in the postsynaptic cell affecting the intrinsic membrane excitability. The intrinsic membrane excitability contributes to the firing properties of a neuron, and is mediated by voltage-gated channels as well as synaptic inputs. In this chapter, we discuss the voltage-gated channels that regulate the intrinsic membrane excitability on the dendrite explaining how these channels contribute to EPSP summation at the soma and back-propagating action potentials. We conclude this chapter with approaches that can be used to measure the intrinsic membrane excitability.