TY - JOUR
T1 - Neural and genetic degeneracy underlies Caenorhabditis elegans feeding behavior
AU - Trojanowski, Nicholas F.
AU - Padovan-Merhar, Olivia
AU - Raizen, David M.
AU - Fang-Yen, Christopher
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2014/8/15
Y1 - 2014/8/15
N2 - Degenerate networks, in which structurally distinct elements can perform the same function or yield the same output, are ubiquitous in biology. Degeneracy contributes to the robustness and adaptability of networks in varied environmental and evolutionary contexts. However, how degenerate neural networks regulate behavior in vivo is poorly understood, especially at the genetic level. Here, we identify degenerate neural and genetic mechanisms that underlie excitation of the pharynx (feeding organ) in the nematode Caenorhabditis elegans using cell-specific optogenetic excitation and inhibition. We show that the pharyngeal neurons MC, M2, M4, and I1 form multiple direct and indirect excitatory pathways in a robust network for control of pharyngeal pumping. I1 excites pumping via MC and M2 in a state-dependent manner. We identify nicotinic and muscarinic receptors through which the pharyngeal network regulates feeding rate. These results identify two different mechanisms by which degeneracy is manifest in a neural circuit in vivo.
AB - Degenerate networks, in which structurally distinct elements can perform the same function or yield the same output, are ubiquitous in biology. Degeneracy contributes to the robustness and adaptability of networks in varied environmental and evolutionary contexts. However, how degenerate neural networks regulate behavior in vivo is poorly understood, especially at the genetic level. Here, we identify degenerate neural and genetic mechanisms that underlie excitation of the pharynx (feeding organ) in the nematode Caenorhabditis elegans using cell-specific optogenetic excitation and inhibition. We show that the pharyngeal neurons MC, M2, M4, and I1 form multiple direct and indirect excitatory pathways in a robust network for control of pharyngeal pumping. I1 excites pumping via MC and M2 in a state-dependent manner. We identify nicotinic and muscarinic receptors through which the pharyngeal network regulates feeding rate. These results identify two different mechanisms by which degeneracy is manifest in a neural circuit in vivo.
KW - Behavior
KW - Feeding
KW - Neural circuits
KW - Optogenetics
UR - http://www.scopus.com/inward/record.url?scp=84906091844&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84906091844&partnerID=8YFLogxK
U2 - 10.1152/jn.00150.2014
DO - 10.1152/jn.00150.2014
M3 - Article
C2 - 24872529
AN - SCOPUS:84906091844
VL - 112
SP - 951
EP - 961
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 4
ER -