States that a jet-lag pill may be available in the future. Where
our biological clock is housed; How the suprachiasmatic nucleus (SCN)
influences circadian variations in body temperature, memory and even the
strength of our grip; How the convenience of a jet-lag pill requires a
chemical solution; Cells taken from SCN and bathed in cAMP (cylic
adenosine monophosphate); cGMP (cyclic guanosine monophosphate).
By
PT Staff, published on November 01, 1994
JETLAG
Ask frequent flyers what they hate most about intercontinental
travel and jet lag will top the list. Our biological clock can take days
to reset, wreaking havoc on sleep patterns. Fortunately, a jet-lag pill
may not be far away.
The clock is housed in the suprachiasmatic nucleus (SCN), a tiny
cellular enclave tucked in the middle of our head. The SCN's
football-shaped halves, each bread crumb-size, influence circadian
variations in body temperature, memory, even the strength of our
grip.
The clock requires no light to run: rats raised in lifelong
darkness still show 24-hour rhythms. But without light cues, the SCN
works like an imitation Rolex, slowly drifting from its proper
setting.
For travelers tortured by traversing time zones, the question is
how to reset the clock quickly. Researchers have identified patterns of
artificial light that advance the clock, so expect "light rooms" in
airports and hotels before long. But a truly convenient jet-lag cure--a
pill that flight attendants could pass out with the peanuts--requires a
chemical solution. Martha Gillette, Ph.D., at the University of Illinois,
finds it takes a chemical cocktail to reset the clock.
When Gillette takes cells from the SCN and bathes them in cAMP
(cyclic adenosine monophosphate), a ubiquitous cellular messenger, the
dock moves ahead about four and a half hours--but only in the day. A
related chemical, cGMP (cyclic guanosine monophosphate), advances the
clock up to six hours, but only at night. Around dusk and dawn, only the
hormone melatonin is effective.
Because cells all over the body use cAMP and cGMP, they aren't
suitable for a jet-lag pill: they may cause too many side effects. But
Gillette suspects researchers will find other neurochemicals that work
largely on the SCN.
ILLUSTRATION
Tags:
adenosine monophosphate,
biological clock,
body temperature,
bread crumb,
chemical cocktail,
chemical solution,
dusk and dawn,
enclave,
frequent flyers,
gillette,
half hours,
hormone melatonin,
intercontinental travel,
jet lag,
medication,
pattern,
sleep,
sleep patterns,
suprachiasmatic nucleus,
time zones,
wreaking havoc
