'Strikingly similar' brains of man and fly may aid mental health research

April 11, 2013
Comparison of fruit fly, mouse and human brains. This new study reveals that similar brain structures regulate comparable behaviors in a similar manner, despite the fact that the brain of species like flies, mice and humans are rather different in size and appearance. Credit: Dr. Frank Hirth, King's College London

A new study by scientists at King's College London and the University of Arizona (UA) published in Science reveals the deep similarities in how the brain regulates behaviour in arthropods (such as flies and crabs) and vertebrates (such as fish, mice and humans). The findings shed new light on the evolution of the brain and behaviour and may aid understanding of disease mechanisms underlying mental health problems.

Based on their own findings and available literature, Dr Frank Hirth (King's) and Dr Nicholas Strausfeld (UA) compared the development and function of the central in arthropods (the 'central complex') and vertebrates (the 'basal ganglia').

Research suggests that both brain structures derive from at the base of the developing and that, despite the major differences between species, their respective constitutions and specifications derive from similar genetic programmes.

The authors describe that in the central complex and the basal ganglia become inter-connected and communicate with each other in similar ways, facilitating the regulation of adaptive behaviours. In other words, the response of a fly or a mouse to internal stimuli such as hunger or sleep, and such as light/dark or temperature, are regulated by similar .

'Strikingly similar' brains of man and fly may aid mental health research
Brain of an adult fruit fly (magenta) in which a substructure of the central complex (CX) is shown (green). Similar to the basal ganglia (BG) in vertebrates, both CX and BG mediate the selection and maintenance of behavioral actions. Their dysfunction results in behavioral defects ranging from motor abnormalities to impaired memory formation, attention deficits, affective disorders and sleep disturbances. Credit: Dr. Frank Hirth, King's College London

Dr Hirth from King's College London Institute of Psychiatry says: "Flies, crabs, mice, humans: all experience hunger, need sleep and have a preference for a comfortable temperature so we speculated there must be a similar mechanism regulating these behaviours. We were amazed to find just how deep the similarities go, despite the differences in size and appearance of these species and their brains."

Dr Strausfeld, a Regents Professor in the UA's Department of Neuroscience and the Director of the UA's Center for Insect Science, says: "When you compare the two structures, you find that they are very similar in terms of how they're organized. Their development is orchestrated by a whole suite of genes that are homologous between flies and mice, and the behavioral deficits resulting from disturbances in the two systems are remarkably similar as well."

In humans, dysfunction of the basal ganglia can cause severe ranging from autism, schizophrenia and psychosis, to neurodegeneration - as seen in Parkinson's disease, motor neurone disease and dementia - as well as sleep disturbances, attention deficits and memory impairment. Similarly, when parts of the central complex are affected in fruit flies, they display similar impairments.

Dr Hirth (King's) adds: "The deep similarities we see between how our brains and those of insects regulate behaviour suggest a common evolutionary origin. It means that prototype brain circuits, essential for behavioural choice, originated very early and have been maintained across animal species throughout evolutionary time. As surprising as it may seem, from insects' dysfunctional brains, we can learn a great deal about how human brain disorders come about."

The findings suggest that arthropod and vertebrate brain circuitries derive from a common ancestor already possessing a complex neural structure mediating the selection and maintenance of behavioural actions.

Although no fossil remains of the common ancestor exist, trace fossils, in the form of tracks criss-crossing the seafloor hundreds of millions of years ago, reveal purposeful changes in direction.

Dr Strausfeld (UA) says: "If you compare these tracks to the tracks left behind by a foraging fly larva on an agar plate or the tunnels made by a leaf-mining insect, they're very similar. They all suggest that the animal chose to perform various different actions, and action selection is precisely what the central complex and the do."

The trace fossils may thus support the early existence of brains complex enough to allow for action selection and a shared ancestry of neural structures between invertebrates and vertebrates.

More information: "Deep Homology of Arthropod Central Complex and Vertebrate Basal Ganglia," by N.J. Strausfeld, Science, 2013.

Related Stories

Recommended for you

'Residual echo' of ancient humans in scans may hold clues to mental disorders

July 26, 2017
Researchers at the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of our brains implicated in mental disorders may be shaped by a "residual echo" from our ancient past. The more ...

Cellular roots of anxiety identified

July 26, 2017
From students stressing over exams to workers facing possible layoffs, worrying about the future is a normal and universal experience. But when people's anticipation of bad things to come starts interfering with daily life, ...

Laser used to reawaken lost memories in mice with Alzheimer's disease

July 26, 2017
(Medical Xpress)—A team of researchers at Columbia University has found that applying a laser to the part of a mouse brain used for memory storage caused the mice to recall memories lost due to a mouse version of Alzheimer's ...

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

NikFromNYC
1 / 5 (4) Apr 11, 2013
The Left has the global warming hoax to back down from, but the Right has the likes of Sarah Palin:

"[Tax] dollars go to projects that have little or nothing to do with the public good — things like fruit fly research in Paris, France. I kid you not."

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.