Reduction of the spinal nucleus of the bulbocavernosous volume by experimental diabetes.

The sexually dimorphic nuclei, spinal nucleus of the bulbocavernosus (SNB) and dorsolateral nucleus, are located at the lumbar segment of the rat spinal cord. These nuclei innervate perineal muscles involved in penile erection and ejaculation. Testosterone levels modulate their size in adult male rats. Because diabetes is associated with low levels of testosterone, we have evaluated morphological changes on spinal cord of diabetic animals. Significant reduction in the SNB volume was observed 4 weeks after diabetes induction accomplished by a reduction on the motoneuronal size. Insulin prevents the morphological alterations. No significant changes were observed on other dimorphic nucleus. The altered sexual behavior of diabetic rats could be consequence of the detected reduction in the SNB volume.