Abstract
The present study was conducted to evaluate the role of the septal neurons for modulation of penile erections during various states of vigilance in rats. A chronic preparation was made fixing a U-shape plate over the skull for semi-restraining the animal in un-anesthetized state. The single units were recorded from the septum simultaneously with recordings of penile erections and EEG. Neurons, which could be recorded, at least during 2 states of vigilance and erectile event were analysed. Erection consisted of a slow increase in corpus spongiosum penis pressure (CSP) with several sharp peaks superimposed on it. Out of 43 neurons recorded during erection across different stages sleep-wakefulness, 26 neurons were related to the erectile activity. The erection related neurons, which showed phasic firing in relation with CSP pressure peaks were grouped as E-phasic (n=15). Two neurons showed increased firing during erection (E-tonic type) while 9 neurons showed decreased firing during erection (I type). Of the 26 erection related neurons, 22 showed relation with erection during REM sleep, while 4 did with erection during waking. These results suggest that a state dependent regulatory mechanism for penile erections is present within this forebrain limbic structure. [J Physiol Sci. 2007;57 Suppl:S138]
