GABA receptors in Caenrohabditis elegans embryonic muscle cells

HERNANDO, G.; BOUZAT, C.

Congreso; XXVI Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011

GABA receptors mediate fast inhibitory neurotransmission in both vertebrates andinvertebrates. They are targets of anxiolytic and antiepileptic drugs as well as ofcommonly used insecticides and antihelminthics. Here we investigated GABA receptorsin the free-living nematode Caenorhabditis elegans, which is a model for the study ofthe nervous system as well as a model of parasitic nematodes. Nematode musclecontains, in addition to two types of nicotinic receptors, a GABA receptor. We used aprimary culture to explore the functional properties of GABA receptors from L1 musclecells at the macroscopic and single-channel levels. Rapid application of GABA to L1muscle cells elicits inward currents that decay fast due to desensitization. In cellattached patches, 1-10mM GABA activates channels of ~ 2.6 pA (membrane potential:+100mV) and a mean duration of about 0.1 ms. The frequency of channel openingsincreases as a function of GABA concentration. The analysis of single-channelproperties shows a homogenous channel population, indicating the presence of a singleGABA receptor subtype. Our study contributes to the understanding of muscle GABAreceptor properties and, in turn, provides new avenues for exploration of anthelmintictherapies.