The lecture on Mondey, 26.8.2024 by the talented neuroscience student Ethan Newnham at U3A Box Hill was a captivating exploration into the complexities of brain science, particularly focusing on dopamine, drug addiction, and how our brains respond to rewards. The session, titled “Rewarding Experiments”, was not only informative but also engaging, as Ethan skillfully balanced the scientific content with relatable examples and a touch of humor.

Ethan started by discussing the fundamental difference between wants and needs, emphasizing how evolution has shaped our brains to prioritize survival. He explained how dopamine, often called the ‘feel-good’ chemical, plays a crucial role in this process by making certain activities rewarding. This naturally led into a deeper dive into the biology of dopamine, where Ethan detailed how this neurotransmitter is released and recycled in the brain, ensuring that it doesn’t overwhelm the system.

The lecture took a fascinating turn as Ethan introduced the famous 1954 experiment by Olds and Milner, where rats were given the ability to self-stimulate their brain’s reward centers. The imagery of rats pressing a button to the point of neglecting food and water to experience the pleasure of dopamine release was both shocking and thought-provoking. Ethan connected this to the human brain, drawing parallels with the nucleus accumbens and how similar pathways are activated in humans.

Ethan also discussed how substances like cocaine and amphetamines hijack this reward system, leading to addiction by artificially boosting dopamine levels. He used graphs to illustrate how our brains predict rewards and how drugs and gambling manipulate this prediction, keeping us hooked on the chase for pleasure.

The lecture ended on a positive note, with Ethan reflecting on why we enjoy certain hobbies, linking our preferences to the dopamine system. He emphasized that while dopamine drives us to achieve our goals and find pleasure, it’s important to be aware of how it can also lead us astray. The audience left with a much deeper understanding of dopamine—not just as a simple pleasure chemical, but as a complex motivator in both positive and negative behaviors. Ethan’s ability to make these complex ideas accessible and engaging made for an enlightening and memorable experience.

Presentation slides and supporting material can be found in our course resources.