Fish, frogs, flies and different fauna in scientific firsts | Spectrum
Over the past century, scientists have used a variety of animal models to improve their understanding of the developing brain and autism. Here is a chronology of some of the groundbreaking discoveries with unusual models of autism.
1916
Notch:
Biologist Thomas Hunt Morgan identifies a fruit fly gene called NOTCH, which affects wing maturation and is part of a pathway that is later linked to the development of the human nervous system.
1920
Heart to heart:
The Austrian scientist Otto Loewi observes parallel activity in two frog hearts suspended in saline solution and suspects that a chemical messenger substance he calls “vagus substance” has traveled through the solution – the first neurotransmitter identified.
1962
Pluripotent possibilities:
The English zoologist John Gurdon replaces the core of a frog’s egg with a core from an intestinal cell. The resulting embryo successfully develops into a tadpole, showing that mature cells contain all of the information necessary to form each cell type and trigger research on induced pluripotent stem cells.
1971
Flight time:
The biologist Seymour Benzer and a colleague show that mutations in a fruit fly gene called PER disrupt the fly’s circadian rhythm and present Drosophila melanogaster as a model for studying behavioral control by genes.
1986
Auger cabling:
Scientists publish the complete wiring diagram of the Caenorhabditis elegans nervous system, paving the way for the widespread use of roundworms in studies of nervous system development.
1990
Elegans experiment:
Studies show that C. elegans is capable of habituation, a simple form of learning that can be disrupted in autism.
2007
Milestone of the mouse:
Researchers present a single gene mouse model for autism: mice with a mutation in the NLGN3 gene.
2010
Crawl forward:
Scientists develop one of the first invertebrate models of autism: a strain of C. elegans with a defective version of the roundworm neuroligin gene NLG1.
2012
Fish story:
A zebrafish study shows that several genes in the 16p11.2 chromosomal region, which can be deleted or duplicated in autism, play a role in brain development.
2015
Social space:
Researchers report that fruit flies tend to keep a reliable distance between themselves in an enclosure, an observation that can be used to study how mutations in genes associated with autism affect social behavior.
2015
Eight is enough:
The full genome sequence of the California two-point octopus (Octopus bimaculoides) is published, showing striking similarities with humans in genes involved in the development and function of the nervous system.
2016
Sedated swimmers:
Zebrafish larvae lacking the autism-related gene CNTNAP2 are hyperactive at night, but adding estrogen-like compounds to their tank calms the fish – demonstrating the animals’ use in screening potential autism treatments.
2018
Two to Tango:
A study of gene expression in the developing fly eye reveals the importance of interactions between genes in the 16p11.2 region during neurodevelopment.
2018
Social cycles:
Researchers identify neurons in the forebrain of zebrafish that aid their social interactions, suggesting that zebrafish can be used to study social brain circuitry.
2019
Set priorities:
An analysis of 20 autism-related mutations in roundworms shows that 10 autism candidate genes are worthy of further investigation. because of their influence on the worm.
2019
Gut feeling:
Scientists find that food moves slowly through the intestines in zebrafish larvae with SHANK3 mutations, providing an indication of the causes of digestive problems associated with autism.
2019
Habit formation:
The behavior of fruit flies with mutations in autism-related genes suggests that dozens of these mutations lead to habituation disorders.
2019
Foreign danger:
Like their counterparts, zebrafish lacking the autism-related RELN gene show little interest in exposure to unfamiliar fish, which supports the use of the fish as a model for social difficulties in autism.
2020
Roundworm Rodeo:
A study of more than 27,000 roundworms with mutations in the worm versions of 98 genes linked to autism indicates the function of these genes; many of them influence habituation.
2020
Sound check:
Zebrafish larvae lacking FMR1, the gene altered in Fragile X syndrome, are hypersensitive to sound, suggesting that zebrafish can be used to study differences in sensory processing in autism.
2021
Show stopper:
The decrease in the expression of the autism-related gene FOXP1 in a specific region of the brain in songbirds affects the birds’ ability to memorize songs they hear from their fathers, suggesting a particular role for this gene in language learning.
2021
Night flight:
Fruit flies, lacking a gene similar to the autism-related genes CHD7 and CHD8, have fragmented sleep, a problem that researchers corrected with an adapted form of “sleep restriction,” a treatment for insomnia.
