About this item:

98 Views | 72 Downloads

Author Notes:

Hirotaka Sakamoto, hsakamo@okayama-u.ac.jp

T.O., K.S., K.T., J.N., R.U., and H.S. performed histological experiments. K.S., K.T., J.F.M., and H.S. performed the electron microscopy analyses. T.O. and S.T. performed surgery and behavior analyses under the supervision of K.T. and H.S. T.O. and D.U. performed optogenetic and in vivo electrophysiology analyses under the supervision of H.S. L.J.Y., A.G., J.F.M., and T.S. interpreted the data and provided advice, antibodies, and equipment. T.O. and H.S. wrote the paper with assistance from L.J.Y., A.G., and J.F.M. The whole study was supervised by H.S. All authors discussed the results and commented on the manuscript.

We thank Akito Otubo for help with the preparation of graphical illustrations.

The authors declare no competing interests.

Subject:

Research Funding:

This work was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) KAKENHI (to H.S.: 24680039, 15K15202, 15H05724, 15KK0257, and 16H06280 [ABiS]; to T.O.: 20K15837) and from the Japan Agency for Medical Research and Development (AMED) (to H.S.: 961149).

T.O., K.S., and K.T. are supported by research fellowships of JSPS for young scientists.

The contribution by L.J.Y. was supported by P50MH100023 to L.J.Y. and P51OD11132 to Yerkes National Primate Research Center (YNPRC)

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Biochemistry & Molecular Biology
  • Biology
  • Cell Biology
  • Life Sciences & Biomedicine - Other Topics
  • PARAVENTRICULAR NUCLEUS
  • PEPTIDE SYSTEM
  • MAGNOCELLULAR NEURONS
  • VOLUME TRANSMISSION
  • PATTERN GENERATOR
  • PENILE ERECTION
  • SOCIAL-BEHAVIOR
  • VASOPRESSIN
  • RAT
  • BRAIN

Oxytocin Influences Male Sexual Activity via Non-synaptic Axonal Release in the Spinal Cord

Show all authors Show less authors

Tools:

Journal Title:

CURRENT BIOLOGY

Volume:

Volume 31, Number 1

Publisher:

, Pages 103-+

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Oxytocinergic neurons in the paraventricular nucleus of the hypothalamus that project to extrahypothalamic brain areas and the lumbar spinal cord play an important role in the control of erectile function and male sexual behavior in mammals. The gastrin-releasing peptide (GRP) system in the lumbosacral spinal cord is an important component of the neural circuits that control penile reflexes in rats, circuits that are commonly referred to as the “spinal ejaculation generator (SEG).” We have examined the functional interaction between the SEG neurons and the hypothalamo-spinal oxytocin system in rats. Here, we show that SEG/GRP neurons express oxytocin receptors and are activated by oxytocin during male sexual behavior. Intrathecal injection of oxytocin receptor antagonist not only attenuates ejaculation but also affects pre-ejaculatory behavior during normal sexual activity. Electron microscopy of potassium-stimulated acute slices of the lumbar cord showed that oxytocin-neurophysin-immunoreactivity was detected in large numbers of neurosecretory dense-cored vesicles, many of which are located close to the plasmalemma of axonal varicosities in which no electron-lucent microvesicles or synaptic membrane thickenings were visible. These results suggested that, in rats, release of oxytocin in the lumbar spinal cord is not limited to conventional synapses but occurs by exocytosis of the dense-cored vesicles from axonal varicosities and acts by diffusion—a localized volume transmission—to reach oxytocin receptors on GRP neurons and facilitate male sexual function.

Copyright information:

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (https://creativecommons.org/licenses/by-nc-nd/4.0/rdf).
Export to EndNote