Jet lag is a temporary sleep condition that happens after long-distance travel throughout numerous time zones. The condition is brought on by a mismatch in between the travelers internal body clock and the new external time environment, leading to signs such as fatigue, sleeping disorders, and decreased awareness.
A recent research study investigated the effect of disrupting the circadian rhythm on adult neurogenesis.
Researchers at the University of Massachusetts Amherst have actually zeroed in on the main cause of unfavorable health effects originating from disturbances to the bodys circadian rhythms, commonly experienced during jet lag or shift work.
The study, released in the journal eNeuro, reveals that the circadian clock gene Cryptochrome 1 (Cry 1) plays an important function in managing adult neurogenesis– the constant creation of nerve cells in the hippocampus area of the brain. Adult neurogenesis is essential for discovering and memory, and disturbances in this procedure have been related to dementia and psychological health disorders.
” Circadian disruption impacts a lot of things,” says lead author Michael Seifu Bahiru, a Ph.D. prospect in the lab of Eric Bittman, Professor Emeritus of Biology. “There are links to high blood pressure, cancer, and diabetes, along with unfavorable effects on neurogenesis.”
Cell birth and survival in the adult hippocampus are regulated by a circadian clock, so its disturbance may shake off the process of neurogenesis. In the U.S. alone, some 30 million individuals experience phase shifts in their body clocks as they work rotating schedules.
Michael Seifu Bahiru is a Ph.D. prospect in the laboratory of Eric Bittman, Professor Emeritus of Biology at UMass Amherst Credit: UMass Amherst.
Bahiru says. “Does the problem come from the act of shifting or the shift itself?”
Bittman explains even more, “Its possible its just changing the light cycle that affects neurogenesis, that jerking your clock around is bad for you, as opposed to the jet lag, which is the time delay that it considers all circadian-dependent systems in your body to get used to this modification in daylight.”
Their findings support the hypothesis that its this internal misalignment, this state of desynchrony between and within organs that happens during jet lag, that is accountable for the negative impact on neurogenesis– and, they believe, other adverse health effects from circadian disruption.
To check their hypothesis, they studied cell birth and distinction in Syrian hamsters with a recessive anomaly in the Cry 1 gene that accelerates the clock in constant conditions and considerably accelerates its ability to shift in response to light. Bittman named the anomaly, discovered in previous research, duper. The research team also evaluated a control group of hamsters without the duper anomaly. Both went through the exact same sequence of modifications in the light cycle.
Results showed that jet lag has little result on cell birth however steers the fate of newborn cells away from ending up being nerve cells. “As anticipated, the duper animals re-entrained quicker, however also were resistant to the unfavorable results of the jet lag procedure, whereas the control– the wild type hamsters– had reduced neurogenesis,” Bahiju says.
” The findings show that circadian misalignment is critical in jet lag,” the paper concludes.
The supreme objective of Bittmans lab is to advance understanding of the pathways involved in human biological rhythms, which might lead to the avoidance of or treatment for the impacts of jet lag, shift work, and circadian rhythm conditions. This most current research study is the next action towards that goal.
Now the team will rely on “a huge unanswered question,” Bittman states– “whether its the operation of circadian clocks in the hippocampus that is being directly regulated by shifts of the light-dark cycle, or whether neurogenesis is controlled by biological rhythms running in cells elsewhere in the body.”
Another possibility, which Bittman thinks is most likely, is that the master pacemaker in the suprachiasmatic nucleus of the hypothalamus in the brain identifies the light shift and then relays it to the stem cell population that has to distinguish and divide in the hippocampus.
Referral: “Adult Neurogenesis Is Altered by Circadian Phase Shifts and the Duper Mutation in Female Syrian Hamsters” by Michael Seifu Bahiru and Eric L. Bittman, 6 March 2023, eNeuro.DOI: 10.1523/ ENEURO.0359-22.2023.
The study was moneyed by the National Institutes of Health.
“Does the issue come from the act of shifting or the shift itself?”
To check their hypothesis, they studied cell birth and distinction in Syrian hamsters with a recessive anomaly in the Cry 1 gene that speeds up the clock in constant conditions and drastically accelerates its ability to move in action to light. They simulated jet lag in the kind of eight-hour advances and hold-ups at 8 16-day periods. Outcomes showed that jet lag has little impact on cell birth however guides the fate of newborn cells away from ending up being nerve cells. “As forecasted, the duper animals re-entrained quicker, but also were resistant to the negative impacts of the jet lag protocol, whereas the control– the wild type hamsters– had actually decreased neurogenesis,” Bahiju states.
