Methods of using unidirectionally propagating action potentials (UPAPs) for cavernous nerve stimulation and for certain disorders are provided. Stimulators capable of creating such UPAPs include, but are not limited to, miniature implantable stimulators (i.e., microstimulators), possibly with programmably configurable electrodes. In one aspect, a method includes providing at least one implantable stimulator with at least two electrodes, disposing the electrodes to apply stimulation that unidirectionally propagates action potentials along a cavernous nerve; and applying the stimulation to the cavernous nerve, thereby treating erectile dysfunction while limiting side effects of bidirectional stimulation.