The constant stress of our daily lives is impairing our ability to remember daily facts and tasks but increasing our fear and anxiety. A finding which could explain the effects of conditions such as post-traumatic stress disorder but also the psychological changes we see in society today.
Shona Chattarji, from the National Centre for Biological Science in Bangalore, India, has been investigating the regions of the brain involved in memory formation and found marked changes in their structure and formation during times of chronic stress.
When it comes to encoding memories, two regions of the brain are involved. The hippocampus handles our daily tasks, facts and events, whilst the amygdala controls our emotional reactions and feelings towards life. Both are located in the temporal lobe of our brains but have very different consequences to a stressful lifestyle.
Dr Chattarji says, ‘Under severe stress, our cognitive abilities get impaired such as remembering daily facts. But at the same time our emotions are out of control. Our fear, aggression, anxiety, is exaggerated. Chronic stress damages the hippocampus, the neurons in that region physically shrink and lose their ability to store information. But this same stress grows neurons in the amygdala bigger and stronger.’
The same stress is causing completely different effects on these two regions of the brain which translates to what is seen in stress disorders such as post-traumatic stress disorders. Chattarji’s team has been researching the drugs available to potentially reverse these changes seen in the brain and have found positive effects using treatments such as anti-depressants. Strikingly, the changes in the emotional amygdala region proved more challenging.
Dr Chattarji explains, ‘The hippocampus changes reverse back to normal, but the amygdala changes take much longer to reverse, which explains why some of the emotional symptoms of stress disorders are so persistent, why we have trouble forgetting the bad stuff. We hope to come across the next generation of drugs which are more effective.’
However, as with any condition, prevention is better than cure. Stress has become so ingrained into our lifestyles today that such a switch is not an easy feat, but is very important.
Dr Chattarji says, ‘We have results in animal models showing how an enriched environment with more playtime and social interaction is effective in countering the detrimental effects of stress. In the urban environment we are plagued with so many stresses. We need changes in our lifestyle to equip us to deal with the stresses that are inevitable.’
ENDS
Notes for Editors
1. Dr Chattarji’s keynote lecture Stress, memory, and the amygdala at the IUPS Congress in Birmingham (ICC), Tuesday 23 July 2013, 16.30-17.15
2. New audio interview with Dr Chattarji. Recorded in May 2013 and available to use – please contact Lucy Holmes (details below).
3. Published research
Ravinder S, Burghardt N, Brodsky R, Bauer E and Chattarji S. (2013) A role for the extended amygdala in the fear enhancing effects of acute selective serotonin reuptake inhibitor treatment. Translational Psychiatry, 3, e209; doi:10.1038/tp.2012.137.
4. Congress of the International Union of Physiological Sciences (IUPS), July, Birmingham
IUPS 2013 is the 37th Congress of the International Union of Physiological Sciences and takes place at the ICC, Birmingham from 21 – 26 July. The congress will bring together over 4,000 physiologists from all corners of the globe to attend over 100 symposia and 30 keynote lectures. The congress has been running since 1889 and was started in an effort to promote physiology, encourage the interchange of ideas, and afford physiologists the opportunity to know one another personally. www.iups2013.org
Contacts
Author:
Shona Chattarji
+91 9980033744, shona@ncbs.res.in
The Physiological Society:
Lucy Holmes, Media and Communications Officer
+44 (0)20 7269 5727, pressoffice@physoc.org