23.11.12

Cat owners beware – a Leeds University study has revealed that a parasite found in cat poo could directly alter the chemistry of the human brain.

The research, led by Dr Glenn McConkey of the Faculty of Biological Sciences,  has provided key evidence that the parasite Toxoplasma gondii (or ‘toxo’ for short) could change production of dopamine in the brain. Dopamine carries messages in the brain controlling aspects of movement, cognition and behaviour – thus triggering schizophrenia and other bipolar disorders.

The Leeds Parasitologist has been examining the parasite for clues to why it has this effect. He carried out research on rodents, in which the effects are more obvious than in humans.

The infected rodents were much more active in running wheels than uninfected ones, suggesting they would be more attractive targets for cats, which are drawn to fast-moving objects. They also seemed to lose their innate fear of cats, increasing the chances of being eaten, which enables the parasite to return to its main host to complete its life cycle.

Dr Glenn McConkey said: “It’s highly unlikely that we will find one definitive trigger for schizophrenia as there are many factors involved, but our studies will provide a clue to how toxoplasmosis infection – which is more common than you might think – can impact on the development of the condition in some individuals.”

Around 10-20 per cent of the UK’s population carries the ‘toxo’ parasite, but most do not suffer apparent health problems.

Outdoor cats only maintain the parasite for three weeks of their life, mostly when they are young and have just begun hunting. Indoor cats do not pose any harm and experts are now devising ways to counteract the parasite’s spread.

Words: Charlotte Duffield