Conference Paper
The evolution of neural circuitry regulating sleep and arousal in the blind mexican cavefish
Stahl, B.A., Jaggard, J.B., Duboue, E.R. and Keene, A.C.
Record Number:
3264
Year:
2017
Journal:
AIM 2017
Abstract:
Sleep is an essential behavior exhibited by nearly all animals, and disruption of this process is
associated with an array of physiological and behavioral deficits. Independent populations of the
blind Mexican cavefish Astyanax mexicanus have converged on sleep loss as a consequence of
life in the subterranean environment, providing a system to examine the effect of evolutionary
history and environmental perturbation on sleep-related processes. Our findings suggest the
wake-promoting neuropeptide Hypocretin (Hcrt)/Orexin underlies sleep loss in cavefish.
Expression of hcrt is increased in cavefish compared to surface fish and pharmacological
inhibition of HCRT signaling restores sleep duration in cavefish to levels equivalent to the
ancestral surface fish. We are currently investigating the evolutionarily derived changes in
HCRT circuitry between cave and surface-dwelling fish. To genetically interrogate the neural
basis for sleep loss in cavefish, we have employed tol2 transgenesis to generate A. mexicanus
expressing the calcium indicator GCaMP6s in peptidergic neurons for subsequent comparisons
of calcium imaging during sleep and wake states in whole brain or HCRT neurons. Moreover,
we are working to generate a brain atlas to serve as a reference for comparison and
understanding the neuroanatomy of the cavefish brain. Together, these resources will facilitate
investigation of the processes governing sleep loss, and more broadly, in identifying the neural
circuits that underlie the evolution of diverse traits in Astyanax cavefish.
Times Cited:
1
Relevent Species: