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. A method of stimulating a cavernous nerve includes providing at least one implantable stimulator with at least two cathodic electrodes; programming stimulation parameters for the cathodic electrodes to radially steer an electric field generated by the cathodic electrodes to apply stimulation that unidirectionally propagates action potentials along a cavernous nerve; and applying the stimulation to the cavernous nerve in accordance with the stimulation parameters to generate orthodromic action potentials traveling in one direction along the nerve, thereby limiting side effects of bidirectional stimulation.