Slide 1

‘Sugar and spice and all things nice’

Chocolate offers brief moments of pleasure because it releases hordes of chemical reactions which end up saying to our brain: ‘I like this…’. The knowledge that our emotions are dependent on chemistry takes some of the magic away, but without this chemistry pleasure wouldn’t exist at all, because we would be incapable of either feeling or remembering it…


Molecule of pleasure…

What makes us feel pleasure? A small molecule known as serotonin, amongst a few others. Serotonin relays the sensation of pleasure to our brain by binding to a receptor protein. This said, serotonin is not only active after we have tasted a truffle. It is also involved in many other of life’s moments: sleep, appetite, the perception of pain and our sexual behaviour. Which all participate, one way or another, in the feeling of pleasure.

…and sometimes sorrow

Serotonin is not the only molecule to relay pleasure. Pleasure depends on many other factors too. And if this elaborate system fails, it can cause disharmonies such as depression for example. Antidepressants can then be prescribed to a patient in the hope of reestablishing the recipe for pleasure.

The downside of treatment

Things are rarely simple. An antidepressant is able to restore a certain balance in someone’s humour yet, as is the case for any drug, it can also cause imbalances elsewhere. This is the kingdom of side effects. A ‘good’ drug will only lightly affect another biological process, whereas a “bad” one can be the cause of damage.

Slide 3

À la recherche du médicament idéal

Il est alors important de tester tous les effets d’un médicament avant de l’autoriser à la vente. Un « bon » médicament sera efficace lorsqu’il n’induit que peu d’effets secondaires. Comment l’évaluer? De nombreux tests de laboratoire existent. L’un d’entre eux va rechercher l’effet du médicament sur d’autres protéines. Aujourd’hui, grâce à un solide support informatique, on peut comparer la production de protéines par une cellule, sans médicament puis en présence d’un médicament. Et l’on retiendra le médicament qui perturbera, idéalement, le moins la production d’autres protéines. Autrement dit, on ne retiendra que celui qui aura le moins d’effets secondaires.

Slide 4