Study by scientists from the Institute of Psychiatry, King's College London unveils how anti-depressants make new brain cells. All types of antidepressants are dependent on the glucocorticoid receptor (GR) to create new brain cells.
The Laboratory of Stress, Psychiatry and Immunology (SPI-lab) at King's has been looking into the role of the GR in depression for a number of years.
In this study, scientists used human hippocampal stem cells, the source of new cells in the human brain, as a new model to investigate 'in a dish' the effects of anti-depressants on brain cells.
"For the first time in a clinically relevant model, we were able to show that anti-depressants produce more stem cells and also accelerate their development into adult brain cells," said Christoph Anacker, a doctorate student at the Institute of Psychiatry at King's and lead author of the study.
"Additionally, we demonstrate for the first time that stress hormones, which are generally very high in depressed patients, show the opposite effect.
"We discovered that a specific protein in the cell, the glucocorticoid receptor, is essential for this to take place. The anti-depressants activate this protein, which switches on particular genes that turn immature 'stem' cells into adult 'brain' cells.
"By increasing the number of new-born cells in the adult human brain, anti-depressants counteract the damaging effects of stress hormones and may overcome the brain abnormalities which may cause low mood and impaired memory in depression.
"Having identified the glucocorticoid receptor as a key player in making new brain cells, we will now be able to use this novel stem cell system to model psychiatric illnesses in the laboratory, test new compounds and develop much more effective, targeted anti-depressant drugs," he added.
The study will be published in the journal Molecular Psychiatry.