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Stress resilience returns with feeling for rhythm
31 August 2010
NWO (Netherlands Organization for Scientific Research)
If your body releases cortisol with fixed regularity then you can cope with stress better, says NWO-funded researcher Angela Sarabdjitsingh. She investigated the rhythm of corticosterone production in rats. This rat hormone is comparable to the human stress hormone cortisol. Rats deal considerably less well with stress if the pattern of corticosterone release changes. An irregular release pattern is a characteristic of chronic stress and stress-related diseases. It might therefore be possible to treat these by restoring the rhythm.
The hormone cortisol has to activate other proteins in the body and brain for a satisfactory response to stress. Yet Sarabdjitsingh discovered that important genes are activated less as soon as the rat’s body is exposed to flattened corticosterone patterns. In a flattened pattern individual pulses are no longer recognisable as there are no more hourly peaks or troughs. That is interesting because conditions such as depression are characterised by a flattened rhythm in the cortisol release. Therefore it might be possible to treat such conditions by using medicines to adjust the rhythm.
Every hour the adrenal glands release the stress hormone cortisol (in rats corticosterone). However, disease or ageing can cause considerable disruption to this hourly rhythm with the result that the body responds less well to stress and pressure. Sarabdjitsingh investigated how the rhythm influences the stress response and the resilience of the hormonal and behavioural stress reaction. She also investigated if any changes in the pattern took place in tissues influenced by the stress hormone.
Besides discovering that the rhythm of corticosterone release is crucial for a good hormonal and behavioural stress response, Sarabdjitsingh found out which protein predominantly suffers under a disrupted rhythm: the glucocorticoid receptor. This protein could therefore be an ideal target for the treatment of stress and stress-related diseases.
Angela Sarabdjitsingh obtained these results by being the first to combine a number of advanced techniques. These methods are now being used by other research groups as well to explore the subject further. Sarabdjitsingh carried out her unique research with a grant from the NWO Mosaic programme. Mosaic is a grant programme that funds the PhD research of students from ethnic minorities. Ethnic minorities are underrepresented within science and NWO, as a strong proponent of diversity, regrets the small number of role models. With Mosaic, NWO wants to prevent scientific talent from being unnecessarily lost.