In the last decade, there have existed public announcements of the discovery of the 'Pain gene' & the 'Fear gene,' genetic strands that influence our decision making process and that have a role in defining what it means to be 'human.'
As with much of genetics, ethical questions surrounding the application of such scientific knowledge abound.
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Thursday, 10 January, 2002, 18:19 GMT
'Pain gene' found
http://news.bbc.co.uk/1/hi/health/1753737.stm
Last Updated: Sunday, 20 November 2005, 00:07 GMT
Gene controlling fear discovered
http://news.bbc.co.uk/1/hi/health/4449226.stm
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Thursday, 10 January, 2002, 18:19 GMT
'Pain gene' found
http://news.bbc.co.uk/1/hi/health/1753737.stm
Scientists have found a gene whose absence can help reduce pain.
Tests on genetically engineered mice which lacked a particular gene showed a "dramatic" loss of sensitivity, appearing to feel up to 50% less pain compared to mice who had the gene.
The discovery by Canadian researchers could one day open the door for the development of drugs to help patients with terminal cancer, chronic backaches and other problems.
The gene concerned is DREAM (downstream regulatory element antagonistic modulator).
The DREAM gene blocks production of dynorphin, a chemical with pain-relieving effects produced in response to pain or stress.
In the mice which did not have the DREAM gene, more dynorphin was produced in the part of the spinal cord involved in transmitting and controlling pain messages.
The mice were discovered to have reduced sensitivity to all types of pain.
Researchers from the University of Toronto, The Hospital for Sick Children and the Amgen Institute said the success in reducing neuropathic pain, sharp - chronic pain resulting from nerve injury - was particularly significant because there are currently no widely effective treatments for this kind of pain.
Different approach
Professor Michael Salter, director of the University of Toronto Centre for the Study of Pain and co-author of the study, said: "Pain is a huge, silent public health crisis that is only beginning to be addressed by researchers.
He added: "There's a great interest in this finding because it's so different from the traditional approaches researchers have been taking to pain management."
At the moment, patients experiencing severe pain are given drugs to control their condition.
A treatment based on the DREAM gene discovery could prove a breakthrough because the mice in the study did not become addicted to the pain control chemicals their bodies produced.
This, say researchers, may prove to be an advantage over the potentially addictive drugs such as morphine.
Professor Saltier said: "These findings point to a novel pharmacological approach to pain management where researchers will be looking for drugs that could block the ability of DREAM to bind to DNA or simply prevent the production of DREAM."
But such a treatment may be hard to develop because the DREAM gene works deep inside cells.
The research is published in the journal Cell.
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Last Updated: Sunday, 20 November 2005, 00:07 GMT
Gene controlling fear discovered
http://news.bbc.co.uk/1/hi/health/4449226.stm
Scientists have discovered a gene that appears to control whether fear reactions to impending danger are appropriate or not.
Mice lacking the gene stathmin appeared fearless in conditions that should instinctively inspire fear.
The gene is expressed in particularly high levels in a part of the brain, called the amygdala, known to be important in human fear.
The US team told Cell their findings could shed light on anxiety disorders.
Daredevil mice
The same researchers from the Howard Hughes Medical Institute identified a similar gene a few years ago, called GPR that appeared to be important in the process of "learned fear".
This is where animals, including humans, learn over time that something is a threat or danger, as opposed to the instinctive fear which animals are born with.
GPR appeared to block the action of "circuitry" in the amygdala of the brain which learns fear.
Conversely, the newer gene discovered, stathmin, appears to help this circuitry.
Mice bred to lack stathmin showed abnormally low levels of anxiety in situations that would normally make a mouse very afraid, such as being in large open spaces - innate fear.
They also reacted less to learned fear.
In the study, this was a neutral tone that was played while the animals were delivered a mild electric shock.
The mice showed a decreased memory for the fearful situations and had difficulty recognising dangerous environments.
Their memory for things other than fear was not impaired, however.
Co-researcher Dr Gleb Shumyatsky, from Rutgers University Piscataway, New Jersey, said these mice could be used to study human phobias and anxiety-related disorders such as post-traumatic stress disorder.
Survival mechanism
"These animal models could be used to develop new anti-anxiety agents," he added.
He said that taken together, their work on genes and anxiety supported clinical data indicating that anxiety is a spectrum of disorders.
He said it was likely that each disorder would have a "unique molecular signature" and therefore require individually tailored drugs for treatment.
Professor Alexander Gardner, a clinical psychologist in Glasgow and member of the British Psychological Association, said: "There is already evidence that the amygdala is involved in fear.
"This is very interesting research indeed."
He said it was important for animals and humans to recognise and respond to fearful situations for survival.
However, he questioned whether fear could be truly innate.
For example, he argued that man was not naturally afraid of fire - man used it to be able to exist in colder climates - but we learn that it can be dangerous and therefore do fear it.
He suggested it might be that certain genes laid down a map in the brain for further acquisition of fear.
