KINGSTON, ON. The way locusts react to stress may provide an important clue to understanding what causes human migraines and how to reduce their painful effects, says Queens University Biology professor Mel Robertson.
With PhD student Corinne Rodgers, Dr. Robertson is using insect models to examine how the nervous system controls breathing when stress is induced through high temperatures and oxygen deprivation. They have discovered that the locusts reaction to extreme heat is very similar to a disturbance in mammals that has been associated with human migraines and stroke.
As a way of temporarily shutting down and conserving energy when conditions are dangerous, the locusts coma has many of the same characteristics seen in people at the onset of a migraine. We feel there may be an evolutionary link between the two, Dr. Robertson suggests.
His teams findings are published on-line in the journal PLoS ONE.
The study monitors locust breathing cycles, which are controlled by a collection of nerve cells in the central nervous system. With heat or lack of oxygen, the insects initially breathe more quickly and then go into a coma. They recover when the temperature comes down again, or oxygen levels rise.
We find that the point of coma is always associated with a surge of extra-cellular potassium ions: the same as has been observed in human brain tissue during surgery, says Ms Rodgers. For the nervous system to work properly, potassium should be high inside cells and low outside, she points out. What were seeing is a failure of that ability to maintain this equilibrium but in fact, in the locust, it appears to be an adaptive response to protect the system.
Also on the Queens team are students Gary Armstrong and John LaBrie, research assistant Kelly Shoemaker and Biology professor Chris Moyes.
Previous research in Dr. Robertsons lab has shown a genetic component to this response, which indicates there
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