Do adult Caenorhabditis elegans suffer from neurotoxicity after being overexposed to volatile anesthetics?

Annotated Bibliography

Do adult Caenorhabditis elegans suffer from neurotoxicity after being overexposed to volatile anesthetics?

a. C. elegans as model organisms (General Statement or few words) i. Ruszkiewicz JA, Pinkas A, Miah MR, Weitz RL, Lawes MJA, Akinyemi

AJ, Ijomone OM, Aschner M. C. elegans as a model in developmental

neurotoxicology. Toxicology and applied pharmacology. 2018.

http://dx.doi.org/10.1016/j.taap.2018.03.016.

doi:10.1016/j.taap.2018.03.016

1. This article discusses the benefits of using C. elegans as a model organism in various research fields. In recent years, C. elegans

have been increasingly used in neural developmental and

toxicology studies. In these experiments C. elegans were exposed

to six toxins and were observed. The results showed that they

shared similarities with mammals in their response to toxins. This

indicates that C. elegans could possibly be used to predict the

effects of neurotoxicants on the developing brain.

ii. Leung MCK, Williams PL, Benedetto A, Au C, Helmcke KJ, Aschner M, Meyer JN. 2008. Caenorhabditis elegans: An Emerging Model in

Biomedical and Environmental Toxicology. Toxicological Sciences.

106(1):5–28. doi:10.1093/toxsci/kfn121.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2563142/.

1. This article further highlights the importance of using C. elegans in toxicology and biomedical research. Although

they are simple creatures, C. elegans contain 60-80% of

human genes. This article also points out the similarities in

the nervous system of C. elegans and vertebrae. Their clear

bodies, short lifespans, and high fertility rates make them

keen specimen to identify genetic alternations.

b. Longterm/overuse of anesthetics could cause neural deficiencies or neurotoxicity 1. Gentry KR, Steele LM, Sedensky MM, Morgan PG. Early

developmental exposure to volatile anesthetics causes behavioral

defects in Caenorhabditis elegans. Anesthesia and analgesia.

2013;116(1):185–189.

i. In this article researchers discuss the ramifications of overusing anesthetics in the developing stages. Anesthetic overexposure

can lead to cell death in the brain which can lead to neural

defects. Young C. elegans exposed were exposed to volatile

anesthetics and were observed. The results showed that

prolonged exposure to anesthetics did cause function

neurological deficiencies.

ii. Awal MR, Wirak GS, Gabel CV, Connor CW. 2020. Collapse of Global Neuronal States in Caenorhabditis elegans under Isoflurane Anesthesia.

Anesthesiology. 133(1):133–144. doi:10.1097/aln.0000000000003304.

1. This article looked to see if the use of isoflurane anesthesia caused desynchrony in the neurons which could result in a

collapse of the nervous system. A light-sheet microscope

was used to image the head of C. elegans whole neural

activity was also measured. The results showed that

isoflurane anesthesia cause disintegration neuronal activity

between neurons at 4% and 8% of dosage.

c. Neurotoxicity has the potential to affect organisms on a genetic level i. Zhang T, Ni C, Li C, Lu P, Chen D, Dong Y, Whetstine JR, Zhang Y, Xie

Z. 2021. Isoflurane impairs oogenesis through germ cell apoptosis in C.

elegans. Scientific Reports. 11(1). doi:10.1038/s41598-021-93737-0.

1. In this article researchers observed the effects of isoflurane anesthetics on fertility rates and oogenesis. It was observed

that while isoflurane did impair oogenesis, it was unclear if

it affected the sperm of male C. elegans. It was also

determined that isoflurane hinders oogenesis by inducting

oxidative stress and germ cell apoptosis (death).

ii. d’Amora M, Giordani S. 2018. The Utility of Zebrafish as a Model for Screening Developmental Neurotoxicity. Frontiers in Neuroscience. 12.

doi:10.3389/fnins.2018.00976.

1. This article does not involve C. elegans but it does introduce the Zebrafish as a potential organism to observe

neurotoxicity. The zebrafish has many advantages such as

its high fertility rate, small size and brain development. The

biggest advantage is that that are morphologically and

physiologically homologous to humans. In order to examine

brain development, gene expression patterns, neural

morphogenesis, and neurobehavioral profiling were used.

However, due to differing protocols, an understanding of the

potential neurotoxicity of chemicals during development has

yet to be reached.