Left: Serial Block Face Scanning Electron Microscopy of a Toxoplasma gondii cyst (green) residing inside a cortical neuron (yellow).
Right: Immunostaining of excitatory and inhibitory synapses in control and toxoplasma-infected mice. Infected mice display spontaneous seizures, as shown in the EEG and EMG traces.
Our lab’s newest direction involves understanding how infectious agents alter the maintenance of neural circuits in the mammalian brain. We are particularly interested in Toxoplasma gondii, an obligate, intracellular parasite that can resides in the brain and skeletal muscle of most warm-blooded animals. Approximately 25% of the US population is infected with this parasite and once infected you remain infected for life. Active infections with Toxoplasma gondii in infants, HIV/AIDS patients, or those with weakened immune systems can lead to toxoplasmosis. However, a number of more recent studies have revealed chronic infections of this parasite can lead to altered behaviors and have been associated with various neurological diseases. In fact, infection with Toxoplasma gondii appears to be a higher risk factor for developing schizophrenia than any single gene mutation identified to date. With this in mind, we are actively investigating how infection with Toxoplasma gondii alters neural circuits that have been previously linked to schizophrenia.