Pigeons sleep like humans

Birds from nap sleep at night, held intensive

Birds compensate a sleep deficit similar to humans. These have now a
new study by German researchers found they report in the current
online issue of the Journal of Sleep Research. Then slumber pigeons,
to be held from noon sleep at night more intense.

Dove at nap

"If pigeons lose sleep when a predator is around, then they can catch
up on sleep at a later time by sleeping more deeply. This mechanism
gives the animals a certain degree of flexibility in meeting their
daily sleep requirement ", Niels Rattenborg, co-author of the study
and director says the research group Sleep and flight in birds at the
Max Planck Institute for Ornithology.

Sleep stages in
In all mammals, including man, sleep consists of two phases: deep,
dreamless "slow-wave sleep" (SW sleep) alternates with dream phases,
the REM sleep are called (English movement for rapid eye). Although
several studies have concluded that newly structured information
during sleep and memories are consolidated, the function of sleep
remains a hotly debated topic among neurobiologists.

Comparative studies in birds may help to clarify here. Because birds
are the only animals besides mammals, which have a biphasic sleep
pattern - possibly because they have relative to their body size
compared to other vertebrates, larger and more complex brains.

Fire in the clock
During sleep, nerve cell groups begin to synchronize. This means that
they fire action potentials in a common clock. These electric currents
can using EEG (electroencephalogram) is derived and the different
rhythms can be made visible. This show characteristic patterns by
which sleep can be divided into several stages. Thus, the deep sleep
phase is characterized by slow waves (frequency less than four Hertz)
and is therefore called "slow-wave sleep."

Suppresses the sleeping humans, increases at a decreasing sleep
duration of the regular amount of slow-wave sleep and the efficiency
of sleep, and mainly during the first few hours. The amplitude of the
waves increased.

Dolores Martinez-Gonzalez, Rattenborg and her team at the Max Planck
Institute for Ornithology have now discovered that birds - not just
put away a sleep deprivation - in this case pigeons. The researchers
thus refuting previous studies in which birds were not on a 24-hour
sleep deprivation as the person responds with different values ​​for
the SW sleep.

Nap "forbidden"
The sleep researchers in their study conditions: They kept the
pigeons from taking naps, the insert that typically the last hours of
the day, at night the animals were allowed to sleep normally. The
amplitude of the characteristic of the SW of slow waves increased,
just as in mammals. That is, the animals slept so well the first few
hours of intense, to sleep without. Overall, the animals were asleep,
but not anymore, because in return, the shortened REM sleep phases.

The type of sleep is regulated in birds seems to be more similar than
previously thought. This increases the chances to learn by studying
animals more about the function of sleep in humans.