Figure 1.
Description
Disrupting the function of sensory neurons of C. elegans can increase their lifespan (Apeld and Kenyon 1999). This effect is not limited to large-scale disruption, as ablation of single pairs of neurons have been shown to modify lifespan (Alcedo and Kenyon 2004; Lee and Kenyon 2009; Liu and Cai 2013). We tested whether silencing the neuron pair ASI with the tetanus toxin light chain (Tetx), as opposed to ablating it, could increase lifespan. Tetanus toxin disrupts neurotransmission by blocking the release of both small clear-core vesicles and large dense-core vesicles, but should not affect communication via gap junctions (Schiavo et al. 1992; McMahon et al. 1992). We expressed GFP::Tetx using the ASI-specific promoter pgpa-4 (Figure Panel A) and conducted lifespan assays comparing animals with high fluorescence and undetectable fluorescence. Tetx in ASI extended lifespan in otherwise wild-type animals (Figure Panel B, Table 1, 14.9% average median lifespan increase across 5 replicates).
Table 1
| Experiment # | Strain | Median Lifespan | Sample Size | P (Tetx vs. Control) | Automated? |
| 1 | Tetx in ASI | 17 | 66 | 0.0125 | no |
| Control | 15 | 55 | |||
| 2 | Tetx in ASI | 16.9 | 118 | <0.0001 | yes |
| Control | 14.4 | 110 | |||
| 3 | Tetx in ASI | 15.9 | 141 | <0.0001 | yes |
| Control | 13.4 | 93 | |||
| 4 | Tetx in ASI | 16.3 | 156 | 0.0471 | yes |
| Control | 14.1 | 86 | |||
| 5 | Tetx in ASI | 23 | 98 | 0.0025 | no |
| Control | 21 | 68 |
Methods
Lifespan assays were conducted as previously described (Apfeld and Kenyon 1999) by hand with no FUDR, as well as utilizing automated lifespan machines (Stroustrup et al. 2013).
Reagents
Strains: CF4126: muEx641[pPC30(pgpa-4::GFP::Tetx) + punc-122::RFP]
Acknowledgments
Funding
NIH R01 AG011816
References
- Alcedo J, Kenyon C. Regulation of C. elegans longevity by specific gustatory and olfactory neurons. Neuron. 2004 Jan 01;41(1):45–55. doi: 10.1016/s0896-6273(03)00816-x. [DOI] [PubMed] [Google Scholar]
- Apfeld J, Kenyon C. Regulation of lifespan by sensory perception in Caenorhabditis elegans. Nature. 1999 Dec 16;402(6763):804–809. doi: 10.1038/45544. [DOI] [PubMed] [Google Scholar]
- Lee SJ, Kenyon C. Regulation of the longevity response to temperature by thermosensory neurons in Caenorhabditis elegans. Curr Biol. 2009 Apr 16;19(9):715–722. doi: 10.1016/j.cub.2009.03.041. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Liu T, Cai D. Counterbalance between BAG and URX neurons via guanylate cyclases controls lifespan homeostasis in C. elegans. EMBO J. 2013 Apr 12;32(11):1529–1542. doi: 10.1038/emboj.2013.75. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McMahon HT, Foran P, Dolly JO, Verhage M, Wiegant VM, Nicholls DG. Tetanus toxin and botulinum toxins type A and B inhibit glutamate, gamma-aminobutyric acid, aspartate, and met-enkephalin release from synaptosomes. Clues to the locus of action. J Biol Chem. 1992 Oct 25;267(30):21338–21343. [PubMed] [Google Scholar]
- Schiavo G, Benfenati F, Poulain B, Rossetto O, Polverino de Laureto P, DasGupta BR, Montecucco C. Tetanus and botulinum-B neurotoxins block neurotransmitter release by proteolytic cleavage of synaptobrevin. Nature. 1992 Oct 29;359(6398):832–835. doi: 10.1038/359832a0. [DOI] [PubMed] [Google Scholar]
- Stroustrup N, Ulmschneider BE, Nash ZM, López-Moyado IF, Apfeld J, Fontana W. The Caenorhabditis elegans Lifespan Machine. Nat Methods. 2013 May 12;10(7):665–670. doi: 10.1038/nmeth.2475. [DOI] [PMC free article] [PubMed] [Google Scholar]