Stress. There is a lot of it about and not always in healthy proportions.
But stress per se has been given a bad rap somewhat unfairly because we need some stress in our lives. Stress has been part of our essential survival kit that has contributed to our successful adaptation and evolution.
Stress is closely linked to performance and while too much stress can be crippling, a short-lived burst of acute stress can really help us to lift our game, to study harder and get better grades by making us cognitively and behaviourally more alert and primed.
O.K these latest studies were done on rodents, not people, but the findings suggest that acute stress which leads to a spike of stress hormone release actually doubled the proliferation of new brain cells in the hippocampus, more specifically in the area of the brain called the dorsal dentate gyrus. This was triggered by the release of a protein (FGF2) from astrocytes, a type of glial cell found in the brain.
Don’t worry about the long names, compare this finding to what is know about the effect of chronic severe stress on our thinking. Persistently elevated stress hormones have been shown to suppress the development of new neurons in the hippocampus and is associated with los of memory.
So far only two areas in the brain have been found to be capable of producing new neurons: the optic bulbs and the dorsal dentate gyrus of the hippocampus.
This short stress response stimulates new neuron production and the effect is then seen a couple of weeks later, by which time the cells have survived and matured into functional neurons that then in these studies where shown to result in improved memory tests.
What isn’t clear is how you can define how long the acute stress that produces this positive effect lasts for. In the rat studies the stress was applied for a couple of hours.
In real life we are exposed to multiple episodes of stress in our daily lives, which may help to keep us alert and maintaining better performance. What isn’t known is why sometimes an acute stress associated with a traumatic event can then lead to conditions such as post traumatic stress disorder associated with a marked lowering of performance and other symptoms.
Daniela Kaufer notes that further research needs to be done to elucidate our further understanding of this area, but basically stress as we know it can always be a different experience different people and the impact it has on us will depend on multiple factors including how much stress we are subjected to, the nature of the stress and our own individual perception or interpretation of it.
Elizabeth D Kirby, Sandra E Muroy, Wayne G Sun, David Covarrubias, Megan J Leong, Laurel A Barchas, Daniela Kaufer. Acute stress enhances adult rat hippocampal neurogenesis and activation of newborn neurons via secreted astrocytic FGF2. eLife, April 16, 2013