Serotonin is a neurotransmitter (brain chemical) that is involved in activation of a small but oh so vital group of brain circuits called the serotonergic pathways. These circuits have a vital role in brain systems involved in mood regulation, emotional behaviour and sleep.
Aggression, a heritable disease?
Studies have shown that because of its links with mood regulation that serotonin may be involved in regulating aggressive behaviours. It appears that it is not so much the amount of serotonin that is important but the turnover rate (the rate at which it is produced, released and recycled) that is the key to linking serotonin to aggressive behaviour. The turnover rate in turn (pardon the pun) is driven by genetic and epigenetic (scary word alert! This just refers to changes in the way the genetic code is released in different individuals) factors. The long and the short of it is that the turnover rate of serotonin can be a heritable feature, which means (get to the point Dr Kate) that abnormalities in serotonin turnover and the behavioural consequences of these can be passed on from generation to generation.
Mood and food
Serotonin provides the bridge between mood and food. This is the chemical responsible for your grouchiness when you are hungry. Serotonin levels are low between meals, they rise in anticipation of food arriving and peak during a meal, especially when you are eating carbohydrates. This peak in serotonin during eating triggers increased activation of serotonergic mood circuitry resulting in a calmer state of mind. Needless to say a great deal of research on mood and food centres on serotonin.
Hot of the press this week is a new role for serotonin in reducing the body’s sensitivity to pain. While the work is in the early phases it has enormous implications for the management of chronic pain.