Intracavernous pressure during erection in rats: an integrative approach based on telemetric recording

To better understand the similarities and differences in the neural control of penile erection occurring in different contexts, we recorded intracaver nous pressure (ICP) in conscious rats using a miniaturized telemetric devic e. ICP changes during reflexive, noncontact, and apomorphine-induced erecti ons were characterized by a plateau increase surmounted by peaks. Plateaus were also elicited by cavernous nerve stimulation in anesthetized rats, sug gesting that the cavernous nerve represents the final common proerectile au tonomic pathway in these contexts and that it responds similarly to informa tion originating in the periphery or in supraspinal nuclei. During reflexiv e, noncontact, and apomorphine-induced erections, activation of spinal auto nomic nuclei, considered the spinal generators of erection, would take plac e first, representing a prerequisite for the occurrence of peaks. Suprasyst olic peaks would result from the addition of pudendal motoneuron activity. In contrast, only peaks were recorded during copulation. In this context, t he convergence of peripheral and supraspinal information apparently elicits the best temporal arrangement of autonomic and somatic outflows, reflectin g a highly organized and integrated spinal activity.