Aldicarb hypersensitivity...

Hi Everyone,

I have a question:

A gene that I’m studying is obviously hypersensitive to Aldicarb, the acetylcholinesterase inhibitor. The basic interpretation is that my gene negatively regulates neurosecretion of acetylcholine or the clustering of acetylcholine receptors to generate this phenotype.

Are there any other commonly (or uncommonly) understood ways to interpreta hypersensitivity phenotype. I’m writing a thesis and want to be cautious about how I present this finding.


You have probably already done so, but if not I recommend reading the chapter in WormBook on acetylcholine and RIC and HIC phenotypes. Have you looked for changes in response to ACh agonists such as levamisole? And examined the sensitivity to GABA drugs to be sure it is ACh specific? Mutations that generally increase neurotransmission (and not just cholinergic neurotransmission) could give you a HIC phenotype. The more drugs you test, the more certain you can be that your response is specific to cholinergic neurons.


I’m with Janet. If you put them on levamisole you can distinguish whether the location of alteration is presynaptic or postsynaptic, something you can’t tell when only using aldicarb. Also, may be less of a problem with your gene as the mutant is hypersensitive, but worth keeping in mind that during an aldicarb assay what you see is more complex than a simple readout of ‘basal’ ACh release. The great Kaplan will tell you that aldicarb treatment can actually double the release of ACh via a neuropeptide-mediated stretch response Good luck with the thesis!


Thanks so much for the advice. Definitely doing some reading. I have a couple of questions:

  1. Levamisole - It seems to me that people often argue that this drug can test for a post-synaptic defect. I understand how this could be the case for something that is Ric (i.e. if you get no response, and you add an agonist and still get no response, then its probably the post-synaptic site). But, if your mutant is Hic, it seems to me you could still make an argument for a pre or post synaptic role

  2. GABA drugs - I can’t seem to find anything about these. The GABA wormbook chapter doesn’t really talk about them.

THANKS SO MUCH! I just love how helpful the worm community is…never switching organisms!

I’d also pay attention to GABA secretion and signaling. Mutations that decrease GABA signaling can cause the muscle to hypercontract, increasing the sensitivity to aldicarb and giving you a HIC phenotype. [Vashlishan, A. B., Madison, J. M., Dybbs, M., Bai, J., Sieburth, D. S., Ch’ng, Q., Tavazoie, M., & Kaplan, J. M. (2008). An RNAi screen identifies genes that regulate GABA synapses. Neuron, 58, 346-61. ]