- LONDON (Reuters) - Scientists
said Wednesday they may have found the key to better treatments for schizophrenia
- They think the clue to controlling the illnesses is the
interaction of proteins on the surface of brain cells that act like night
club bouncers deciding how much dopamine and other brain chemicals to let
into the cell.
- Dopamine is linked to pleasure and addiction. Other brain
chemicals called GABA are associated with learning, memory and emotion.
Too much or too little dopamine and GABA chemicals produce many of the
symptoms of schizophrenia and addiction.
- ``This is the first demonstration that these proteins
actually 'talk' to each other,'' Dr Hyman Niznik, of the University of
Toronto, said in a telephone interview.
- Niznik and his colleagues have discovered how the protein
systems interact and join together.
- ``This may provide us with a new therapeutic window on
how to restore normal cellular function in diseases like schizophrenia
with the right medication that can either block this interaction or make
it happen,'' Niznik explained.
- There are many different types of receptors in the brain.
Some, like D1 and D5, respond to the same drugs but others are very specific.
- In a report in the science journal Nature, Niznik describes
how dopamine D5 receptors can directly alter the function of GABA receptors
by binding to them. Scientists had previously thought that other proteins,
called G-proteins, were also needed.
- ``We've shown how these two receptor proteins bind to
each other in order to modify each other's function,'' said Niznik.
- ``It's like cutting out the middle guy -- you don't need
the G-protein to let these receptors talk to each other. We believe this
to be a very general phenomenon.''
- Niznik and his colleagues think people suffering from
schizophrenia, which occurs in 1.5 percent of the world's population, have
a coupling problem between brain receptor proteins.
- The findings open up another avenue for treating schizophrenia,
different from the approach of antipsychotic drugs which target other brain
- Schizophrenia is the most common form of severe mental
illness. Its causes are still unknown but scientists know it affects chemicals
in the brain and believe there is a biological link which can predispose
a person to the disease.
- Sufferers experience hallucinations, hear voices and
suffer from depression and bizarre and often violent behavior. The illness
usually begins in the late teens or early 20s.