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Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
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October 11, 2012--------News Archive Return to: News Alerts


The hippocampus is an area of the brain that is important for consolidation
of information into memories and helps us to learn new things.

WHO Child Growth Charts

       

Discovery of Gatekeeper Nerve Cells Explains the Effect of Nicotine on Learning and Memory

Researchers have discovered a new group of nerve cells that regulate processes of learning and memory – acting as gatekeepers, they carry a receptor for nicotine, which helps explain our ability to remember and sort information

The discovery of the gatekeeper cells, which are part of a memory network together with several other nerve cells in the hippocampus, reveal new fundamental knowledge about learning and memory.

This study is published today in Nature Neuroscience.

The hippocampus is an area of the brain that is important for consolidation of information into memories and helps us to learn new things. The newly discovered gatekeeper nerve cells, also called OLM-alpha2 cells, provide an explanation to how the flow of information is controlled in the hippocampus.

"It is known that nicotine improves cognitive processes including learning and memory, but this is the first time that an identified nerve cell population is linked to the effects of nicotine," says Professor Klas Kullander at Scilifelab and Uppsala University.


Humans think, learn and memorize
with the help of nerve cells sending signals
between each other. Some nerve cells send
signals far away to other areas of the brain,
while other neurons send signals within the same area.

Local nerve circuits in the hippocampus
process impressions and turn some
of them into memories.
But how does this work? And how can
nicotine improve this mechanism?


The new research study literally sheds new light on this intriguing mechanism.

"We have used a new technology called optogenetics, in which light is used to stimulate selected nerve cells. We were amazed when we discovered that light activation of the gatekeeper cells alters the flow of information in the hippocampus in the same way as nicotine does," explains coauthor Richardson Leão.


Through research on mice, scientists show
that gatekeeper cells connect to the principal cell
of the hippocampus.

Active gatekeeper cells prioritize local circuit signals
arriving to the principal cell, while inactive gatekeeper
cells allow input from long-distance targets.

Nicotine activates the gatekeeper cells,
thereby prioritizing the formation of memories
via local inputs.


Next, the scientists want to test which types of memory and learning may be selected for by the activation of gatekeeper cells. With such knowledge, it may be possible to stimulate these nerve cells by artificial means, for example by selective nicotine-like drugs, to improve memory and learning in humans.

"Ideally, one would like to access the positive effects of nicotine on the hippocampus's ability to process information, but without creating the strong nicotine dependence that keep smokers addicted to inhaling dangerous tobacco smoke," says Klas Kullander.

Original article: http://www.eurekalert.org/pub_releases/2012-10/uu-dog100512.php