An alarming number of people are knowingly or otherwise abusing over the counter pain medications. Could there be another way? Aoibhinn and Jonathan take each on in a pain-off (!) and test whether a technique known as transcranial direct current stimulation could increase their pain thresholds. Meanwhile Kathriona finds out what it's like to live with chronic pain, discovers some fascinating and perhaps unexpected benefits of placebos, and meets researchers who are trying to capitalise on the naturally produced cannabis-like chemicals in our own body to help relieve pain.

Water is something we often take for granted, but it's a hugely valuable resource that plays a vital part in every aspect of our lives. Kathriona finds out how our increasing use and recycling of plastic is creating microplastics, tiny particles which ultimately contribute to the Plastic Soup swirling around the world's oceans. Aoibhinn investigates new diagnostics and technologies for treating water infected with cryptosporidium, and Jonathan meets Teagasc researchers using forensic geoscience to trace where sediment originates to analyse potential threats to aquatic flora and species such as the Freshwater Pearl Mussel.

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.

"A gut instinct…", "misery guts", "guts for garters", "gut wrenching"; we've been obsessed with it for centuries, but increasing evidence proves a healthy gut plays a crucial role in a healthy body & mind. Aoibhinn discovers the challenges of getting probiotics into our gut when most bacteria die in the acidic juices of our stomach, Kathriona finds out why many researchers now consider the gut to be our second brain and are investigating which bacteria could be key to developing a range of psychobiotics (mood controlling bacteria) and Jonathan reveals how analyzing the evolving gut microbiota of infants could provide new opportunities for improving infant health and the optimising infant milk formula composition.

From people who are involved in terrible accidents, to the general wear and tear of our bodies as we age, advances in robotics and biomaterials are transforming lives worldwide. Aoibhinn meets Stephen Lowry from Newry who, having lost his hand in a bomb attack in the 80s has had his life transformed by his new bionic prosthesis. Kathriona investigates brain stimulation devices for treating diseases like Parkinson's, and Jonathan looks into advanced stem cell therapy that could help regenerate damaged heart cells after a heart attack.

Dogs… frogs… flying… balloons… our fears and phobias can be as bizarre as they are diverse! But how are our fears created in the first place? And what happens inside our brain when we feel the fear?! In this week's show, Aoibhinn gets up close and personal with some rather large spiders to better understand and perhaps even overcome her arachnophobia, Kathriona investigates how fears can be created, and Jonathan willfully submits himself for some ‘water-boarding' and uncovers some disturbing truths about the neuroscience of torture.