A change in the ion selectivity of ligand-gated ion channels provides a mechanism to switch behavior.

PIRRI J (*) IGUAL CONTRIBUCIÓN; RAYES D (*) IGUAL CONTRIBUCIÓN; ALKEMA MJ

PLOS BIOLOGY

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2015

1544-9173

Behavioraloutput of neural networks depends on a delicate balance betweenexcitatory and inhibitory synaptic connections. However, it is not known whether network formation and stability isconstrained by the sign of synaptic connections between neurons within thenetwork.  Here we show that switching thesign of a synapse within a neural circuit can reverse the behavioraloutput.  The inhibitory tyramine-gatedchloride channel, LGC-55, induces head relaxation and inhibits forwardlocomotion during the C. elegansescape response.  We switched the ionselectivity of an inhibitory LGC-55 anion channel to an excitatory LGC-55cation channel.  The engineered cationchannel is properly trafficked in the native neural circuit and results inbehavioral responses that are opposite to those produced by activation of theLGC-55 anion channel.  Our findingsindicate that switches in ion selectivity of ligand-gatedion channels (LGICs) do not affect network connectivityor stability and may provide an evolutionary and a syntheticmechanism to change behavior.