THE ROLE OF COMPLEXIN IN NEUROTRANSMITTER RELEASE

Neurons communicate using specialized connections called synapses by releasing synaptic vesicles (SVs) containing neurotransmitters. How this process is regulated is not completely understood, although some of the key molecules have been identified. Complexins are a family of protein found primarily in the nervous system of all animals. We investigated the role of complexin 1 (cpx-1) in the nematode C. elegans. We found that cpx-1 null mutants paralyzed far quicker in aldicarb than wildtype animals. Furthermore, the null mutants displayed severe locomotory defects; the null mutants showed about a 70% decrease in body bends per 20 seconds. Introducing a complexin GFP fusion protein into GABA motor neurons alone did not rescue the mutants; these animals displayed the exact defects as the null mutants, suggesting that null defects are independent of the GABA motor neurons. However, putting the same complexin back into all neurons did rescue the null mutants; rescue animals paralyzed on aldicarb with a wild-type time Course and showed about a 150% increase in body bends than the null mutant. Our data suggest not only that complexin plays a critical role in neurotransmitter release but also that complexin is an inhibitor of this process. Furthermore, our data also imply that including a C terminal GFP does not impair complexin function. Through further analysis of complexin, we hope to better understand the protein's function in regulating synaptic transmission.