Brains today are expensive—metabolically speaking, that is. Pound for pound, the human brain demands a huge amount of energy to support its recently evolved language and social skills. Now a study offers some of the first strong evidence that the rapid development of our metabolically costly brain may have led to an unfortunate by-product: when energy prob­lems arise, the result may be schizophrenia.

No one knows exactly what causes schizo­phrenia, a debilitating disorder characterized by psychosis and severe cognitive impairments. One theory, which suggests it is a consequence of our brain’s high metabolism, has been around for years—but until now scientists had not devel­oped a way to test it.

In the new study—a rare combination of evolutionary genetics and med­icine—research­ers in China, Germany and the U.K. compared gene expres­sion (when and where in the body certain genes are active) and concen­trations of meta­bolites (small molecules crucial for metabolic processes) in the post­mortem brains of people without schizophrenia with those in the brains of chimpan­zees, rhesus macaques and human schizo­phrenics. They determined that the genes and metabolites that are altered in schizo­phrenia appear to have changed rapidly in recent human evolution. More important, they are related to energy metabolism.

Because these changes may have happened recently (on an evolutionary scale), we may not yet have developed ways to cope with energy problems that arise, according to study co-author Philipp Khaitovich, an evolutionary biologist at the joint Max Planck/Chinese Academy of Sciences Institute for Compu­tational Biology in Shanghai. Khaitovich suggests that the brain could be operating at the limit of its energy-regulating abilities, so it might be easy for something to go wrong, as in the case of schizophrenia.

This study may begin to explain why schizophrenia exists but not necessarily why some people are more predisposed to it than others, says Matthew Keller, an evolutionary behavioral geneticist at the University of Colorado at Boulder, who was not involved with the study.

Khaitovich agrees that the work is just a glimpse into the mechanisms responsible for our uniquely human abilities, but the findings do put metabolism in the spotlight for future research. Once we understand what makes our brains special, we can begin to understand what goes wrong in schizophrenia, he says.

Note: This article was originally published with the title, "Schizophrenia's Roots".

2 Comments

1. 1. Anathea 12:21 PM 1/30/09

   Genes also determine people's suspeceptibilty to environmental toxins. Mercury has been found to play a major role in a number of psychiatric disorders. In mainstream schizophrenia certain half-truths are perpetuated. Recent research shows that oxidative stress can be regarded as a marker, but poeple living in the vicinity of cell towers also have high levels of oxidative stress, resulting in a number of neurological complaints, from headaches, to insomnia, memory loss to depression.
   As early as the 1970s, David Horrobin found evidence that schizophrenia is a disorder of the metabolism, caused by a lack of essential fatty acids, Supplementation with omega3, found in linseed oil, can make sufferers comepletely free of symptoms. The development of Clozapine was based on this research, but the origianl research has been systematically suppressed. Clozapine and the new atypical mind-alterning anti-psycholtic drugs have devastating side-effects and they create life-long users. Instead of being healed, patients are made cash-cows of a profession that is not a science in the proper sense.
   You find a number of Horrobin's publication at: http://www.scribd.com
   Jonathan Campbell wrote a comprehensive article about this matter that should soon be investigated as one of the biggest crimes against humanity.
   http://www.cqs.com/schizophrenia.htm

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2. 2. Ruchira 08:49 AM 1/19/12

   In another study Crespi B. et al. has presented findings to suggest that at least some of the genes that are responsible for Schizophrenia have been positively selected through the evolutionary process, with a very high heritability, which is somewhat paradoxical for a disease with phenotypes which exhibits negative fitness. They too somehow concludes it is, though paradoxically, a maladaptive condition. http://rspb.royalsocietypublishing.org/content/274/1627/2801.full.pdf+html
   
   But could these findings be interpreted through a different model of evolutionary genetics?
   
   For example Schizophrenia and Bipolar Disorder are known to share common, both phenotypes and genotypes . It is also know that some of those who are affected with Bipolar Disorder could carry out many times the amount of work they carry out normally or a normal individual. For example a person who does manual labor for living, during a manic episode might carry out two or three times the amount of work he/she usually carries out. Could this and above Khaitovich et al's findings of deranged metabolic processes in Schizophrenia have some association. Could this derangement of the cellular level metabolic processes found in Schizophrenia not a limiting factor of the phenotypes or cognitive abilities from an evolutionary perspective, but poorly adapted and expressed evolutionary potential of a higher level? Is that the reason why there was positive selection of Schizophrenia genes through the evolutionary process? Could we find biological evidence for this conceptual formulation that might lead to a novel model or a hypothesis with which Schizophrenia could be framed and explained? Therefore research aimed at therapeutics of it.
   
   http://ruchirakitsiri.blogspot.com/2012/01/evolutionary-genetics-of-schizophrenia.html
   

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