brainwave
Jedi Master
Interesing conclusion to come out of the National Institue of Mental Health. An evolutionary psychologist was pushing this idea for a while two years ago.
I want them to know when this varient of the DARP-32 gene showed up. It would have serious implications if it was around the time of cro-magnon appearance and Neanderthal disappearance. This striatal/ pre-frontal cortex curcit has a huge role in memory, learning, reward, executive planning, etc.
http://www.news(dot) com(dot) au/story/0,23599,21201390-2,00.html
ONE of the most devastating types of mental illness could be a by-product of the evolution of human beings' intelligence, a new genetic study has suggested.
Scientists have discovered that a common version of a particular gene appears both to enhance a key thinking circuit in the brain, and to be linked to a raised risk of schizophrenia.
The findings, from a study by the US National Institute of Mental Health, provide fresh evidence for the theory that schizophrenia is the price some people pay for our species' advanced intellectual abilities.
The research hints that some of the genetic factors that underpin the human brain's cognitive capacities can also go wrong, leaving a sizeable minority prone to mental illness.
In the study, the NIMH team examined a common variant of a gene called DARPP-32. Three-quarters of the subjects studied inherited at least one copy of it.
This common version of the gene appears to make the brain's most sophisticated thinking region more efficient, the researchers found.
It improves the way information is exchanged between the striatum, a brain region that processes reward, and the prefrontal cortex, the brain's executive hub that manages thoughts and actions.
When this circuit works efficiently, the normal outcome is more flexible thinking and better memory.
But the circuit has been linked to brain functions that go wrong in patients with schizophrenia.
An investigation of 257 families with a history of the condition showed the improving version of DARPP-32 was more common among people who had developed the mental illness.
Daniel Weinberger, of NIMH, said it was possible that while a more efficient link between the prefrontal cortex and striatum normally improves cognitive ability, it may have a negative effect when other genetic and environmental factors interfere.
The result could be a predisposition to schizophrenia, known to be caused by a combination of genes and a person's environment.
"Our results raise the question of whether a gene variant favoured by evolution, that would normally confer advantage, may translate into a disadvantage if the prefrontal cortex is impaired, as in schizophrenia," Dr Weinberger said.
"Normally, enhanced cortex connectivity with the striatum would provide increased flexibility, working memory capacity and executive control.
"But if other genes and environmental events conspire to render the cortex incapable of handling such information, it could backfire - resulting in the neural equivalent of a superhighway to a dead end."
Details of the study are published in the Journal of Clinical Investigation.
Previous research, notably by Nobel laureate Paul Greengard, of Rockefeller University, has established that DARPP-32 acts in the striatum to route information to the brain's cortex for processing.
It operates through the neurotransmitter dopamine, thought to be overactive in people with schizophrenia.
The new work, to which Dr Greengard contributed, is the first to show a link between the gene and more efficient brain circuitry, and possibly to schizophrenia.
I want them to know when this varient of the DARP-32 gene showed up. It would have serious implications if it was around the time of cro-magnon appearance and Neanderthal disappearance. This striatal/ pre-frontal cortex curcit has a huge role in memory, learning, reward, executive planning, etc.
http://www.news(dot) com(dot) au/story/0,23599,21201390-2,00.html
ONE of the most devastating types of mental illness could be a by-product of the evolution of human beings' intelligence, a new genetic study has suggested.
Scientists have discovered that a common version of a particular gene appears both to enhance a key thinking circuit in the brain, and to be linked to a raised risk of schizophrenia.
The findings, from a study by the US National Institute of Mental Health, provide fresh evidence for the theory that schizophrenia is the price some people pay for our species' advanced intellectual abilities.
The research hints that some of the genetic factors that underpin the human brain's cognitive capacities can also go wrong, leaving a sizeable minority prone to mental illness.
In the study, the NIMH team examined a common variant of a gene called DARPP-32. Three-quarters of the subjects studied inherited at least one copy of it.
This common version of the gene appears to make the brain's most sophisticated thinking region more efficient, the researchers found.
It improves the way information is exchanged between the striatum, a brain region that processes reward, and the prefrontal cortex, the brain's executive hub that manages thoughts and actions.
When this circuit works efficiently, the normal outcome is more flexible thinking and better memory.
But the circuit has been linked to brain functions that go wrong in patients with schizophrenia.
An investigation of 257 families with a history of the condition showed the improving version of DARPP-32 was more common among people who had developed the mental illness.
Daniel Weinberger, of NIMH, said it was possible that while a more efficient link between the prefrontal cortex and striatum normally improves cognitive ability, it may have a negative effect when other genetic and environmental factors interfere.
The result could be a predisposition to schizophrenia, known to be caused by a combination of genes and a person's environment.
"Our results raise the question of whether a gene variant favoured by evolution, that would normally confer advantage, may translate into a disadvantage if the prefrontal cortex is impaired, as in schizophrenia," Dr Weinberger said.
"Normally, enhanced cortex connectivity with the striatum would provide increased flexibility, working memory capacity and executive control.
"But if other genes and environmental events conspire to render the cortex incapable of handling such information, it could backfire - resulting in the neural equivalent of a superhighway to a dead end."
Details of the study are published in the Journal of Clinical Investigation.
Previous research, notably by Nobel laureate Paul Greengard, of Rockefeller University, has established that DARPP-32 acts in the striatum to route information to the brain's cortex for processing.
It operates through the neurotransmitter dopamine, thought to be overactive in people with schizophrenia.
The new work, to which Dr Greengard contributed, is the first to show a link between the gene and more efficient brain circuitry, and possibly to schizophrenia.