Pontine control of ejaculation and female orgasm

Area of Science:

• Neuroscience
• Physiology
• Sexual Health

Background:

• Ejaculation and micturition share physiological similarities as voiding activities.
• Both processes rely on supraspinal pathways for pelvic organ coordination.
• Supraspinal pathways for ejaculation and female orgasm are not well understood.

Purpose of the Study:

• Identify brainstem activation during male ejaculation and female orgasm.
• Compare brain activation patterns between sexual climax and micturition.

Main Methods:

• Positron emission tomography (PET) used to map brain activity.
• Participants underwent manual penile or clitoral stimulation to induce climax.
• PET scans captured brain activation patterns during sexual climax.

Main Results:

• Ejaculation and orgasm activated distinct left dorsolateral and right ventrolateral pontine tegmentum regions.
• The dorsolateral area showed activation even in women who failed or imitated orgasm.
• The ventrolateral area was exclusively active during ejaculation and female orgasm.

Conclusions:

• The left dorsolateral pontine tegmentum, termed the pelvic organ-stimulating center, is active during male ejaculation and female orgasm.
• This center influences pelvic organs for voiding via sacral parasympathetic motoneurons.
• The right ventrolateral pontine tegmentum, the pelvic floor-stimulating center, mediates pelvic floor contractions during climax via direct projections to pelvic floor motoneurons.