**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below. For a copy of the full completion report, please contact the author via e-mail at chungyuw@msu.edu. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**
SEA LAMPREY
PHEROMONES MODULATE LOCOMOTOR RHYTHMICITY
Erin J. Walaszczyk1,
Yu-Wen Chung-Davidson1, Weiming Li1
113 Natural Resources
Building, Michigan State University,
East Lansing, MI, 48823
February 2016
ABSTRACT:
All
animals are partially controlled by a number of circadian rhythms. These are
physical, behavioral, or genetic changes that occur on an approximate 24 hour
time cycle and allow the organism to coordinate its internal and external
environments. These rhythms are endogenous, but can be affected by external,
environmental cues. Sea lamprey offer a unique model to understand locomotor
rhythmicity, as throughout their life cycle they switch from a nocturnal rhythm
in locomotor activity to arrhythmic multiple times. Adult female sea lamprey
respond behaviorally to mature male sex pheromones that guide them to
appropriate spawning grounds and induce spawning behaviors. Our overall
hypothesis is that locomotor rhythmicity in adult female sea lamprey is
modulated by sex pheromone compound. Field tests confirmed that pre-ovulated
and ovulated female locomotor activity is affected during exposure to
spermiated male washings (SMW), and that in ovulated females SMW can alter the
locomotor pattern. The effects of individual SMW compounds were investigated
using controlled laboratory studies, and results showed that SMW as well as two
components of SMW, 3-keto petromyzonol sulfate (3kPZS) and petromyzonol sulfate
(PZS), have differential effects on pre-ovulated and ovulated female locomotor
activity. We have also demonstrated that there are effects of these sex
pheromones on the GABAergic system in the brain and pineal complex related to
neural circuits that guide locomotor activity production. Studies here add to
the knowledge of sex pheromone influences on behavior, circadian timekeeping
mechanisms, and locomotor activity and rhythm production in this species. The results here provide further information
on how sex pheromones affect adult females in the sea lamprey and how they
could contribute to control efforts for this species.