A new study done on mice shows that scientists might be one step closer in finding a “cure” for jet lag.
When the “master clock” in the brain gets out sync with the actual time- most people complain that they are experiencing “jet lag”. The master clock tells you that you should go to bed when it’s actually your lunch time.
The master clock is found in the suprachiasmatic nucleus (SCN) inside the brain. Nerve cells inside the SCN are influenced by the sun and sync themselves to the 24-hour rotation period of the earth.
The study, published recently in the journal Neuron, reports that some of the cells in the SCN are more influential than the other cells and the reason behind this is that 10 percent of all these cells produce a molecule called the “vasoactive intestinal polypeptide” (VIP)- in humans as well as mice. This molecule often dictates how the nerve cells will communicate and sync with each other.
The research team hypothesized that these VIP neurons are like “grandmothers” who tell all the cells what to do but the team could not figure out how the neuron activity affected the release of VIP neurons.
To find out how the VIP neurons interacted with each other, scientists recorded electrical impulses produced by the neurons in a bunch of VIP neurons in a lab dish for a period of 3 days.
The team found that neurons talk to each other in two ways: “Tonic” VIP neurons gave out steady electrical impulses while the “irregular” VIP neurons would give out electrical impulses in double and triple bursts with equal spaces of non-activity between these bursts.
To know more about these neurons, researchers conducted an experiment with some mice. They disrupted their master clocks by keeping them in the dark all day and night. Then they would deliver a zap to the cells at a specific time every day- which was similar to flying to a new time zone.
If the VIP neurons were giving out steady electrical impulses, it took the mice quite longer to adjust to the new “time zone” whereas when the neurons gave out irregular electrical impulses, the mice seemed to adapt well and quickly. The team then understood that it was the irregular electrical impulse pattern that made the neurons release VIP chemicals.
“VIP, we think, is the juice that is capable of shifting the clock faster,” said Erik Herzog, biology professor at Washington University in St. Louis.Since the study was done in mice, the research team notes that further studies needs to be done to findings will be similar in humans.