A Change in the Ion Selectivity of Ligand-Gated Ion Channels Provides a Mechanism to Switch Behavior.
Behavioral output of neural networks depends on a delicate balance between excitatory and inhibitory synaptic connections. However, it is not known whether network formation and stability is constrained by the sign of synaptic connections between neurons within the network. Here we show that switching the sign of a synapse within a neural circuit can reverse the behavioral output. The inhibitory tyramine-gated chloride channel, LGC-55, induces head relaxation and inhibits forward locomotion during the Caenorhabditis elegans escape response. We switched the ion selectivity of an inhibitory LGC-55 anion channel to an excitatory LGC-55 cation channel. The engineered cation channel is properly trafficked in the native neural circuit and results in behavioral responses that are opposite to those produced by activation of the LGC-55 anion channel. Our findings indicate that switches in ion selectivity of ligand-gated ion channels (LGICs) do not affect network connectivity or stability and may provide an evolutionary and a synthetic mechanism to change behavior.
Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
Jennifer K
JK
Pirri
Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America; Instituto de Investigaciones Bioquímicas de Bahía Blanca, UNS-CONICET, Bahía Blanca, Argentina.
Diego
D
Rayes
Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
Mark J
MJ
Alkema
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001522:Behavior, Animal / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D005818:Genetic Engineering; D008969:Molecular Sequence Data; D017982:Receptors, Biogenic Amine / Q000235:genetics / Q000378:metabolism*; D055366:Synaptic Potentials; D014439:Tyramine / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; C542018:LGC-55 protein, c elegans; D017982:Receptors, Biogenic Amine; D014439:Tyramine