Dr. Anthony Hannan, along with Dr Caitlin
McOmish, Emma Burrows and colleagues, characterised a genetically
altered mouse and discovered that it had schizophrenia-like behaviours,
including learning and memory problems, the inability to process
complex information, and abnormal responses to particular sensory
The scientists found the mouses condition significantly
improved by simply giving them enhanced mental and physical
exercise putting running wheels in their cages, plus
interesting items to smell, see and touch.
Not only did the mouses schizophrenia-like symptoms ease
through this environmental enrichment, but a specific chemical
transmitter pathway found to be abnormal in the cerebral cortex
of the mice was selectively rescued.
An anti-psychotic drug used by humans also improved the mouses
condition, indicating that this mouse is a valid model for schizophrenia
in humans. Dr Hannan said this discovery could pave the way
for the development of better treatments for schizophrenia.
Through our research, and that of others, we hope a new
class of therapeutic drugs will be developed that mimic the
effects of environmental enrichment in the brain to treat various
brain disorders, possibly including schizophrenia, Dr
Pharmaceutical approaches may not be the sole answer
for a given brain disease. People may still need optimal levels
of physical and mental activity, as well as a healthy diet,
plus the right drugs.
We have already identified specific molecules that could
be targets for what I call enviromimetics and these
may have relevance for other brain diseases. However,
there are obviously major differences between mice and men,
and large-scale clinical trials are needed to identify the most
beneficial drugs, he said. Schizophrenia is a brain disorder
that is brought on through a complex and largely unknown interaction
of genes and environment.
There is a nature-nurture aspect to schizophrenia because in
human identical twins, if one twin develops schizophrenia, there
is only a 50% chance the other twin, who has identical genes,
will develop the illness.
Dr Anthony Hannan's ground-breaking environmental enrichment
studies have previously shown that a combination of mental and
physical exercise could delay the onset and progression of Huntingtons
disease. As well as movement problems (e.g. chorea) and cognitive
deficits (culminating in dementia) this disease has psychiatric
symptoms, which can include depression and psychosis.