Some young creatures carry a hidden fault that stays quiet for a time, letting them grow and move through the world as their companions do, until a season of maturing brings on lasting changes in how they relate to others, how they feel fear, and how they respond with anger. Scientists at Griffith University, working with zebrafish that each lack one member of a family of genes known to be bound up with human psychiatric illness, have seen this same patient unfolding of a disorder that appears to be rooted in the body's oldest biological instructions. Their finding suggests that even behaviour
Zebrafish Lacking Neurexin Genes Show Delayed Mental-Health-Like Behaviours, Offering a New Research Model
Normal early on, then profound, permanent changes as they mature
Mark
Why does it matter that these fish seem normal at first?
Mimi
Because that's the human pattern too. The researchers say the delay closely mirrors how schizophrenia and autism trajectories unfold, so the fish offer a way to study the period before symptoms show.
Mark
And what changed once they matured?
Mimi
Social behaviour, anxiety and aggression, all affected permanently after the juvenile stage, in fish missing specific neurexin genes.
Luke
I want to be careful with the word 'mirrors.' Fish showing anxiety-like or social changes isn't the same as fish having schizophrenia. The researchers say features resemble human conditions, and that's a claim about resemblance.
Mimi
Fair. The wording is that fish can experience features of these conditions, not the full conditions.
Mark
So what's the practical promise?
Mimi
Working backwards to find when brain circuits start diverging, then testing whether treatment can prevent, delay or reverse the changes.
Luke
That's a stated goal, not a result. The reporting doesn't say any treatment has been tried or worked.
Mark
What about the claim that behaviour is deeply encoded in DNA?
Mimi
Giacomotto's point is that changing one gene family was enough to reshape behaviour permanently, which surprised people who see it as mostly learned.
Luke
Which is his interpretation. It doesn't say experience doesn't matter, and the piece doesn't give sample sizes or mention peer review.
Der Puls
- Zebrafish missing neurexin genes look perfectly normal at first, so the trouble stays hidden until the juvenile stage arrives.
- Once maturity sets in, the fish show lasting shifts in social behaviour, anxiety and aggression that mirror human psychiatric patterns.
- The delayed timing echoes how schizophrenia and autism unfold in people, unsettling the idea that such behaviour is shaped mainly by environment.
- Researchers at Griffith University are working backwards to find when brain circuits begin to diverge and what triggers that shift.
- The next step is to test whether treatments can prevent, delay or even reverse these changes, moving from genes to mechanisms to therapies.
Some young creatures carry a hidden fault that stays quiet for a time, letting them grow and move through the world as their companions do, until a season of maturing brings on lasting changes in how they relate to others, how they feel fear, and how they respond with anger. Scientists at Griffith University, working with zebrafish that each lack one member of a family of genes known to be bound up with human psychiatric illness, have seen this same patient unfolding of a disorder that appears to be rooted in the body's oldest biological instructions. Their finding suggests that even behaviours we think of as shaped chiefly by experience and learning may rest on a deeper, shared inheritance, and it offers a way to watch the first quiet divergences before they harden into illness.
Young zebrafish that lack a particular family of genes seem, for a long while, like any other young fish. They grow, swim and behave in ordinary ways. Then, as they reach the juvenile stage, something shifts, and the changes that follow are lasting and specific.
That pattern is the heart of new work from Griffith University's Institute for Biomedicine and Glycomics. The team built what they describe as the world's first complete set of zebrafish models, each missing one member of the neurexin gene family, genes strongly linked to psychiatric disorders. Early on, the researchers saw no obvious differences in brain development or behaviour. The differences appeared only after maturity, and they were profound, permanent and highly specific.
Dr Jean Giacomotto noted that the animals functioned remarkably normally early in life. As they matured, removing particular neurexin genes led to major changes in social behaviour, anxiety and aggression, the same features affected in patients, and with surprisingly comparable timing. For him, the result challenges the assumption that such behaviours need enormous biological complexity. Social life is usually credited mainly to experience and learning, yet altering one gene family was enough to reshape how these animals relate to others. Perhaps even complex behaviour rests on deeply conserved genetic programs.
That delayed course is also what makes the models valuable. Because the fish follow a path resembling human disease, the team hopes to observe the silent neural changes that come before a mental health condition takes hold. They can now work backwards to find when brain circuits begin to diverge, and what sets off that transition. They also want to know whether intervening before severe behaviour appears is possible, and whether it could reverse changes already underway.
The models are meant as a platform for searching for such treatments. Giacomotto summed up the goal as a path from genes, to mechanisms, to treatments. The work is still at the model-building stage. The next steps are mapping when the circuits diverge and testing whether any treatment can alter the course.
Young zebrafish that lack a particular family of genes look, for a while, like any other young zebrafish. They develop normally and behave normally. Then, as they reach the juvenile stage, something shifts, and the changes that appear are lasting and specific.
That pattern is the central finding of work from Griffith University's Institute for Biomedicine and Glycomics. The researchers built what they describe as the world's first complete collection of zebrafish models, each missing a member of the neurexin gene family. Neurexins are among the genes most strongly linked to psychiatric disorders.
In the early stages of development, the team saw no obvious differences in brain development or behaviour between these fish and ordinary ones. The differences emerged later, once the fish matured. The researchers describe the changes as profound, permanent and highly specific, and they say the delayed timing closely resembles how conditions such as schizophrenia and autism unfold in people.
Dr Jean Giacomotto said the animals functioned remarkably normally early in life. As they matured, he said, removing particular neurexin genes led to major changes in social behaviour, anxiety and aggression. These are features also affected in patients, and with surprisingly comparable timing.
Giacomotto argues that the result challenges assumptions about how much biological complexity such behaviours require. He pointed out that social behaviour is usually thought of as shaped mainly by experience, environment and learning. Yet altering a single family of genes was enough to reshape, permanently, how these animals interact with others and respond to their surroundings. In his view, even highly complex behaviours may arise from deeply conserved biological and genetic programs.
The delayed onset is also what makes the models useful. Because the fish follow a course resembling human disease, the researchers say they have a window into the silent neuronal changes that come before a mental health condition appears. Giacomotto said the team can now work backwards to identify when brain circuits begin to diverge and what triggers that transition. They can also ask whether intervening before severe behavioural changes emerge is possible, and whether it might even reverse changes after they have appeared.
The models are also intended as a platform for searching for treatments that could prevent, delay or reverse these changes. Giacomotto summed up the aim as moving from genes, to mechanisms, to treatments.
The work is at the model-building stage. The next steps are mapping when the circuits diverge and testing whether any treatment can alter the course.
Bemerkenswerte Zitate
Even highly complex behaviours may arise from deeply conserved biological and genetic programs.— Dr Jean Giacomotto, Griffith University
The ultimate goal is to move from genes, to mechanisms, to treatments.— Dr Jean Giacomotto, Griffith University
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