The brain is the most complex organ in the human body. It produces our every thought, action, memory, feeling and experience of the world. But what happens when the brain goes wrong? Jonathan gets an MRI scan to reveal the structure and activity in his brain, and then meets 2FM DJ Rick O'Shea who has been living with epilepsy since he was a teenager. Aoibhinn finds out about the first study to link deterioration of parts of the brain with structural changes in patient DNA and gene activity, and Kathriona visits the RCSI Brain Bank to find out how brain donation is crucial to furthering our understanding of brain diseases.