Are nipples are attached to the vagus nerve ?

Hey J4 -- here's the $ 1.67 summary:

General Findings:
It’s tempting to build a case for a vagus presence in the breast, based on sensory experience and the influence of both Prolactin and Oxytocin on breast tissue and milk production. (1) Further general discussions of the vagus indicate connections to all internal organs save for the adrenals. (7) But, when tracing out each of those trunks, there’s no mention of breasts, lacrimal tissue etc.
The seminal work (1840) on this topic appears to be reference (4) which makes for some fascinating reading regarding the connection of the nipple to the uterus. (Gawd, “the ancients knew” and I didn’t find out until a sunny afternoon in the park in 1951 when my g/f clued me in – had I studied more instead of playing ball, I could have had two more years of good times !) Cooper however attributes this relationship to the ‘grand sympathetic nerve’ implying that it’s all CNS and any “connection” must be in a low level of the brain stem.. (I’d hazard a synaptic loop somewhere below the mid-brain, if such loops can exist/form – I didn’t trace out the actual nerve paths for such a loop.). Here’s the detailed quote from Cooper:
“.The fourth dorsal nerve appears just below the fourth
rib, emerging through the intercostal space from the inner
part of the chest. It almost immediately divides into two
nerves ; the upper branch passes to the external mammary
artery, and descends with it to the upper part of the mamma.
The second branch passes upon the surface of the breast and
advances to the basis of the nipple, where it divides into
branches which supply its papillae.” (4)

Two other anatomical writings from medical references (2, 3) deal with preservation of sensation during breast augmentation surgery and the more radical surgery for breast cancer. Neither indicates the presence of a vagus nerve connection and only addresses nerves originating in the spine.

Butt, testing is fun and maybe we need some empirical data : Anyone know something about how the nipple-to- g-spot connection functions before and after breast augmentation – OK guys, we need a large sample size (not cup size) here. Old, wired, monogamous types need not contribute! (Just remember, anything more than a handful is a waste!) 🙂

That said, reference (5) reports some electronic microscopy in sheep that has some unidentified nerve fibers in lacrimal tissue. Tempting to wonder if perhaps the major anatomical dissections may have missed something that was very tiny or tightly attached to a very small artery. OTOH, the more conventional explanation is more like what we see in the cavernosa of the penis. The endings of nerves in the pudendal bundle generate the nitric oxide that overcomes pde5 and kick starts the erectal process. To the best of my knowledge, that’s all CNS.

Some possible thoughts that, “rain on the vagus parade:”
The prolactin – prostate connection (6) :
Possible path: nip->brain stem->pituitary-prolactin->prostate

Best avenues for further research appear related to:
Breast Cancer,
Breast Augmentation (particularly with regard to preservation of sensation)
Of note, oxytocin in involved in this vagal stimulation (they used a oxytocin antagonist to determine this effect.)
Comment: (from prior, non-scholarly reading) Males produce a pulse of oxytocin from the testes or scrotal sac upon ejaculaton. That may may be aimed at vagal nerve stimulation or its action might be confined to nerves in the pudendal bundle.

So J4, you got it, your basic $ 1.67 draft research summary. Recommendation: Don’t hold your breath but I’ll keep my eyes open and should a wart, nipple or hair follicle erect I’ll clue you in.

Meanwhile, another thought. For years, nip-stim has been early in my foreplay repertoire and it has seemed like a sure fire way to light up the female genitals and brain. (small sample size: n
(4) On the anatomy of the breast, by Sir Astley Paston Cooper, 1840
(5) Nerve-Myoepihelium and Nerve-Glandular Epithelium Contacts in the Lacrimal gland of the Sheep; Akio Yamauchi, Geoffrey burnstock, Dept. of Zoology, Univ. of Melbourne, Victoria Australia. Sept 1, 1967.
(6) http://www.rbej.com/content/4/1/28
(7) http://www.reference.com/browse/vagus+nerve