Scientists are working on the theory that schizophrenia reacts in the brain much the same as jet lag, putting our body clocks at odds with the rest of the body. Since those who suffer from schizophrenia often complain of problems with sleep a study published in the British Journal of Psychiatry neuroscientists believe they are closer to answering the question as to why a genetic mutation that triggers schizophrenia-like symptoms in mice also seems to turn the body clock (circadian rhythm) out of whack.
The study was trying to determine how schizophrenia was linked mental illness to sleep disturbances. University of Oxford researchers used mice to investigate the circadian patterns in mice with a defect in the SNAP25 gene, which has been associated with schizophrenia in humans. The mice were kept on a 12 hours of light followed by 12 hours of darkness schedule. They were active when they were supposed to be sleeping, which suggests that their circadian rhythms were disturbed.
Circadian rhythms are made up of a patch of brain tissue, call the suprachiasmatic neucleus (SCN) that takes information it gathers about light and passes it along to the rest of the body. In modified mice the rhythms of SCN are usually normal, but there are mutations in the production of proteins that form the communications between the SCN and the rest of the body. These signals of communication make sure that the peripheral clocks ticking in tissue, like through the skin, liver or adrenal glands, remains coordinated with the body’s main clock. It doesn’t have much to do with the clocks we use on our nightstands so much as it does with the timing of light and darkness.
Russell Foster, head of the Oxford research team, says there were alterations in the time of day when hormones were released from the adrenal glands compared with normal mice. There is a defect in the way that the master clock in the SCN is talking to peripheral clocks, says Foster. It’s rather like jet lag. All of the biology is in different phases.
The team has yet to prove a direct cause to schizophrenia, Foster believes that if sleep is disrupted it is more likely to push individuals toward mental illness. Once you disrupt sleep you precipitate a raft of additional problems that make things worse and further destabilize the neurotransmitter systems of the body, he says.
This study is of particular interest because there are several other illnesses associated with disruption of the circadian clocks (like those found in people who work a split shift). This would include cardiovascular disease, Type II Diabetes, obesity and high cholesterol.
The mouse findings are particularly interesting because several other illnesses associated with disrupted body clocks as a result of shift work, are also particularly common in people with schizophrenia, says These include cardiovascular disease, adult-onset diabetes, obesity and high cholesterol.
The similarity between the illnesses seen in schizophrenic patients and those with disrupted circadian timing suggests that circadian deregulation contributes significantly to their [cause],says Lance Kriegsfeld of the University of California, Berkeley. The findings suggest that development of therapeutic agents designed to normalize SCN signaling in schizophrenic patients may go a long way in improving their quality of life and longevity.
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NewScientist — Disrupted Body Clock May Prime You for Schizophrenia: http://www.newscientist.com/article/dn21371-disrupted-body-clock-may-prime-you-for-schizophrenia.html
NewScience — Linking Genes, Cerebellums and Schizophrenia: http://www.newscientist.com/article/mg21328525.200-linking-genes-cerebellums-and-schizophrenia.html