Conference Paper

A cavefish brain atlas reveals functional and anatomical evolution of morphology and neural activity with convergence of sleep and feeding circuits

Jaggard, J., Lloyd, E., Loomis, C., Cook, C., Vega, P., McGaugh, S., Rohner, N., Bohrner, J., Duboue, E. and Keene, A.C.

Record Number:
4269
Year:
2019
Journal:
AIM 2019
Pages:
19
Abstract:
Neural morphology, circuitry, and activity are all essential in representing behavioral outputs among animals. Complex behaviors such as sleep and feeding are present in nearly all phyla, yet the evolution and neural circuitry that underlie these behaviors remains largely unclear. The Mexican cavefish, Astyanax mexicanus, exists as surface populations that inhabit rivers, and multiple cave populations with convergent evolution of feeding behaviors and sleep loss. A. mexicanus, provides a powerful system to investigate behavioral adaptation and whole-brain evolution. To understand behavioral evolution in context of the neural circuits involved in generating behaviors, it is necessary to assign imaging of circuitry and neural activity to anatomical maps of the nervous system. Here, we describe the development of high-resolution comparative brain atlases of four populations of A. mexicanus. These atlases reveal altered neural morphological landscapes among cave populations. Further, whole-brain pERK activity mapping demonstrates significant changes in brain activity patterns. Imaging of hypothalamic circuits underlying feeding and sleep shows convergent evolution in cave populations. Lastly, behavioral and pharmacological sleep and feeding assays show distinctly altered brain activity patterns in populations of cave-adapted animals compared to surface-dwelling populations. Taken together, these findings establish the first cellular-resolution brain atlases for comparative evolution in populations of the same species that exhibit vastly different behaviors, allowing for the direct interrogation of how behaviors and brains evolve.
Times Cited:
1