Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 23, 2010 | Supplemental Material + Accepted Version
Journal Article Open

A Hormone-Activated Central Pattern Generator for Courtship


Background: Medicinal leeches (Hirudo spp.) are simultaneous hermaphrodites. Mating occurs after a stereotyped twisting and oral exploration that result in the alignment of the male and/or female gonopores of one leech with the complementary gonopores of a partner. The neural basis of this behavior is presently unknown and currently impossible to study directly because electrophysiological recording techniques disrupt the behavior. Results: Here we report that (Arg^8)-conopressin G and two other members of the oxytocin/vasopressin family of peptide hormones induce in Hirudo verbana a sequence of behaviors that closely mimic elements of spontaneous reproductive behavior. Through a series of progressively more reduced preparations, we show that one of these behaviors, a stereotyped twisting that is instrumental in aligning gonopores in preparation for copulation, is the product of a central pattern generator that consists of oscillators in ganglia M5 and M6 (the ganglia in the reproductive segments of the leech), and also in ganglion M4, which was not previously known to play a role in reproductive behavior. We find that the behavior is periodic, with a remarkably long cycle period of around five minutes, placing it among the slowest behavioral rhythms (other than diurnal and annual rhythms) yet described. Conclusion: These results establish the leech as a new model system for studying aspects of the neuronal basis of reproductive behavior. Highlights: Oxytocin/vasopressin homologs induce precopulatory movements in a leech. These movements are generated by a central pattern generator. Segmental ganglia M4, M5, and M6 can each generate fictive behavior in isolation

Additional Information

© 2010 Elsevier Ltd. Received 22 December 2009; revised 1 February 2010; accepted 5 February 2010. Published online: March 11, 2010. Available online 11 March 2010. We thank B. Olivera for his role in earlier stages of this work, K. Murphy and J. Chang Han for preliminary work (while they were undergraduates) on characterizing how conopressin affects behavior, C.R. Lee for her careful studies on latency measurement, J. Ram for sharing his specimens and knowledge of Nereis with us, and J. Murphy for maintaining our breeding colony and observing reproduction. This work was supported by grants MH43396 from the National Institutes of Health and IOS0825741 from the National Science Foundation (both to W.B.K.), by a fellowship from the Broad Foundations (to D.A.W.), by Microsoft Research, and by a private gift from R. Geckler. D.A.W. holds a Career Award at the Scientific Interface from the Burroughs Wellcome Fund.

Attached Files

Accepted Version - nihms182518.pdf

Supplemental Material - mmc1.pdf

Supplemental Material - mmc2.mpg

Supplemental Material - mmc3.mpg


Files (7.9 MB)
Name Size Download all
977.0 kB Preview Download
1.6 MB Preview Download
2.2 MB Download
3.2 MB Download

Additional details

August 19, 2023
October 20, 2023