Recent research studies have noted that “mutant mice with an autism gene display striking learning and memory skills mirroring those seen in human ‘savants’”; the September 6th Science Daily further suggests that a mouse model of autism spectrum disorders has been developed:
Mice with this mutation show a similar type of social impairment and cognitive enhancement as the type seen in some people with autism spectrum disorders (ASDs). ASDs are enigmatic cognitive disorders that impair a patient’s social interactions, but do not necessarily limit their intelligence.
The scientists said the mice they developed may represent an important advance in modeling autism spectrum disorders in mice and offer researchers a new tool for understanding how specific defects in neural development may lead to autism.
The genetically engineered mice, who have been shown to have “enhanced learning and memory skills” due to having a “mutant version of a gene called neuroligin-3″ are being studied at the Howard Hughes Medical Institute in Chevy Chase, Maryland. Neuroligin-3 is involved in the functioning of synapses.
Elsewhere, at the University of North Carolina at Chapel Hill School of Medicine, researchers are investigating drosphilia—the fruit fly—to study another protein, neurexin. The researchers deleted the gene for neurexin in the fruit flies and found that they had “trouble moving”; further investigation revealed that the flies were missing half of their synapses:
What was left were deformed, making it impossible for them to send out all the chemical signals that are necessary.
The next step in the research, which is already underway, is going to be to find out what proteins neurexin binds to as well as how they interact with each other and what the exact order of events is that result in the successful organization of the synapses within the nerve cells. They hope that eventually the research will lead to understanding the role of neurexin in functions like learning and memory and thereby finally understanding how defects in this one protein cause disorders such as autism.
As Mike Stanton noted in a post about these research studies,
Drosophila are an important part of the biological research toolkit. Their relatively simple genome and rapid reproductive cycle have made them a favourite of biologists researching the mechanics of evolution. But autistic fruit flies? Autism is a complex social disorder. Fruit flies are not complex social beings.
Mice, too, are not “complex social beings”; how one might diagnose a mouse with autism is not exactly clear. A non-verbal mouse is nothing too unusual. Genetically engineering animals to have some autistic traits (as per DSM critieria) can begin to tell us how some things about the interaction between genes and synaptic functioning in the brain. But autism (the human kind, at any rate) is much more than having certain learning and memory skills, or certain kinds of synaptics connections.
Is autism something particularly distinct to humans?