Conference Paper
Distinct neural mechanisms underlie the convergent evolution of sleep loss in Astyanax
Jaggard, J.B., Robinson, B., Oh, I., Masek, P., Yoshizawa, M. and Keene, A.
Record Number:
3097
Year:
2015
Journal:
AIM 2015
Abstract:
Sleep is a fundamental behavior found nearly ubiquitously throughout the animal
kingdom, yet the function of sleep remains largely unknown. A defining characteristic of
sleep is elevated arousal threshold, where a greater sensory stimulus is required to induce
response during sleep relative to waking states. While this feature of sleep is conserved
across phyla, the biological basis underlying interactions between sleep and sensory
processing remains poorly understood. In the Mexican cavefish, Astyanax mexicanus, the
evolution of cave populations has resulted in the convergent evolution of sleep loss,
providing a unique opportunity to examine the evolution of sleep in response to a
changing environment. In addition to sleep changes, A. mexicanus cave populations have
enhanced non-visual sensory systems including a greater number of mechanoreceptive
lateral line neuromasts that detect water motion and vibration. Here, we investigate the
relationship between sensory systems and sleep. Ablation of the lateral line with
gentamicin restores surface fish levels of sleep in Pachón cavefish, suggesting that
increased sensory input from the lateral line underlies sleep loss. Localized lateral line
ablations, and analysis of surface-cave hybrids reveal superficial neuromasts in the trunk
and cheek are required for sleep loss. Strikingly, no effect of lateral line ablation on sleep
is observed in four different cave populations tested. Therefore, these findings suggest
enhanced sensory input underlies evolutionarily-derived sleep loss in Pachón cavefish,
and also, suggest that distinct sensory bases regulate the evolutio
Times Cited:
1
Relevent Species: