Context

Recently, researchers at the Tata Institute of Fundamental Research (TIFR), Mumbai, have found a new function for Serotonin.

About

What is Serotonin?

• It is a chemical that signals between neurons.
• It is believed to help regulate mood and social behaviour, appetite and digestion, sleep, memory, and sexual desire and function.
• There may be a link between serotonin and depression. If so, it is unclear whether low serotonin levels contribute to depression, or if depression causes a fall in serotonin levels.
• At the level of an organism, serotonin is known to be involved in coping with stress. However, the underlying mechanism of its neuro-protective role was unknown.

Mechanism of Serotonin for coping with stress

• Serotonin is involved in the generation of new mitochondria (the powerhouse of the cell) in neurons, increased cellular respiration and fuel (ATP) in the cell.
• As it generates more mitochondria, thereby giving neurons the capacity to produce more energy and the ability to cope with stress better.
• It can impact the manner in which neurons grapple with stress and affect the trajectory of ageing.

Recent Discovery

• It reduces reactive oxygen species, thus providing neuroprotection against cellular stress.
• Serotonin signalling could be used to prevent mitochondrial abnormalities and neuronal loss
• This newly identified function of serotonin has been studied in mice and rats. If found to be true in humans, which is likely to be the case, it may have important medical implications.

Neuronal loss is a major cause of neurodegenerative diseases such as in Alzheimer’s and Parkinson’s. Abnormal mitochondrial functions are known to cause or contribute to neuronal death. Unlike other cells. Neurons are not generated continuously and so identifying factors that increase mitochondrial health is key to prevent ageing-associated neurological diseases.

 

Experimental Proof

• Neurons exposed to Serotonin not only produced more fuel (ATP), even the efficiency of mitochondrial output in these neurons was higher. This was seen in experiments done both in tissue culture and rats/mice.
• This study paves way for further research into designing therapeutic interventions by combined activation of Serotonin.
• This may help tackle mood disorders and age-associated neurological decline.