RRC ID 65887
Author Hecker A, Schulze W, Oster J, Richter DO, Schuster S.
Title Removing a single neuron in a vertebrate brain forever abolishes an essential behavior.
Journal Proc Natl Acad Sci U S A
Abstract The giant Mauthner (M) cell is the largest neuron known in the vertebrate brain. It has enabled major breakthroughs in neuroscience but its ultimate function remains surprisingly unclear: An actual survival value of M cell-mediated escapes has never been supported experimentally and ablating the cell repeatedly failed to eliminate all rapid escapes, suggesting that escapes can equally well be driven by smaller neurons. Here we applied techniques to simultaneously measure escape performance and the state of the giant M axon over an extended period following ablation of its soma. We discovered that the axon survives remarkably long and remains still fully capable of driving rapid escape behavior. By unilaterally removing one of the two M axons and comparing escapes in the same individual that could or could not recruit an M axon, we show that the giant M axon is essential for rapid escapes and that its loss means that rapid escapes are also lost forever. This allowed us to directly test the survival value of the M cell-mediated escapes and to show that the absence of this giant neuron directly affects survival in encounters with a natural predator. These findings not only offer a surprising solution to an old puzzle but demonstrate that even complex brains can trust vital functions to individual neurons. Our findings suggest that mechanisms must have evolved in parallel with the unique significance of these neurons to keep their axons alive and connected.
Volume 117(6)
Pages 3254-3260
Published 2020-2-11
DOI 10.1073/pnas.1918578117
PII 1918578117
PMID 32001507
PMC PMC7022180
MeSH Animals Axons / physiology Embryo, Nonmammalian / physiology Escape Reaction / physiology* Larva / physiology Nervous System / growth & development* Neurons / cytology* Neurons / physiology* Zebrafish
IF 9.412
Zebrafish Tol-056