A team at the University of Leeds has discovered how a parasite transmitted via cat faeces may trigger the development of schizophrenia and bipolar disorders. The toxoplasmosis parasite, which can also be spread to humans through raw or undercooked meat, may play a role in the development of these disorders by interfering with the production of the neurotransmitter, dopamine. Glenn McConkey, senior lecturer at Leeds' Institute of Integrative and Comparative Biology and lead researcher on the project, said that toxoplasmosis "changes some of the chemical messages in the brain", with a huge effect on behaviour. "Studies have shown there is a direct statistical link between incidences of schizophrenia and toxoplasmosis infection, and our study is the first step in discovering why," he said. A paper on the research was recently published in the Public Library of Science journal.