Results tagged “Memory” from Choline Baby

A new study by Scott Swartzwelder and other researchers at Duke University Medical Center suggests that choline taken during pregnancy can result in "supercharged" brains for the infant.  The new study shows this is due to having bigger brain cells in key segments of the brain.

Choline, is found in egg yolks, liver and other meats - "exactly the kind of things people were told not to eat" due to their high cholesterol content, says Swartzwelder.

Dr. Shartzwelder believes their results in the rats could translate to humans, and indeed the US Institute of Medicine added choline to the list of essential nutrients, particularly for pregnant women, in its 2003 recommendations.

The implications of the study's findings are "potentially huge" Swartzwelder believes: "If it turns out that it's true in humans and can make people smarter their whole lives and forestall age-related memory decline - that's potentially a very exciting prospect."

Hannah Theobald, a nutrition scientist at the British Nutrition Foundation, calls the study "really interesting" but cautions that more research needs to be done before any recommendations can be made in humans.

Anatomy and physiology - Behavioural studies have shown giving choline to pregnant rats improves learning and memory in their offspring. The pups also suffer significantly less from failing memories as they get old.

However, it was not known whether choline's effects were on the general brain environment or whether it fundamentally changed the brain's cells.

"Our study is the first time anyone has shown that prenatal choline supplementation actually changes the anatomy and physiology of single brain cells," Swartzwelder told New Scientist. No adverse effects could be seen in the rats, he adds.

The team gave pregnant rats three to four times their normal intake of choline for six days. Gestation lasts about 21 days in rats, and the period during which the rats were fed extra choline roughly corresponds to the start of the third trimester in women.

Electrical signals  - The pups born were raised to adulthood and then their brains were examined, in particular the hippocampus - the area of the brain critical for learning.

This part of the brain was sliced in a way that preserved its internal circuitry and kept it alive. A tiny electrode was then used to recording the behaviour of each cell. The neurons of rats born to mothers given extra choline fired electrical signals more rapidly and for longer periods, indicating a capacity to communicate more easily.

The team then injected a biological dye into the neurons to look at their shape and structure. The cells from rats receiving prenatal choline supplements were substantially bigger than those from rats that did not.

"We are looking at consistent changes in the range of 20 to 25 per cent," says Swartzwelder. "These are bigger cells with more dendrites, the areas of the cell specific to receiving incoming signals." He says the combined changes induced by choline in the physiology and anatomy of the brain cells would "hotwire" the system.

Better membranes  The team does not know exactly how choline boosts brains, but it is known to contribute to the building of cell membranes during the embryo stage of development. "My bet is it has something to do this," Swartzwelder says.

Previous work by Steven Zeiser at the University of North Carolina has shown choline alters a crucial gene by adding a methyl group on to it. This switches off the gene, CDKN-3, which usually inhibits cell division in the memory regions of the brain.

There is little information on how much choline women currently take. "But don't be afraid of eggs," Swartzwelder suggests. "I used to eat a low fat diet - I've started eating eggs and I'm not even pregnant!"

However, Theobald warns that some foods rich in choline should be avoided during pregnancy. For example, liver is also high in retinol which can cause birth defects. And certain choline-rich fish like swordfish and tuna can also have a high mercury content, which is harmful to fetuses.

Original Source of Research Study Information:  Journal of Neurophysiology (vol 91 April issue)

A new study out of Duke University suggests some important benefits of supplementation during pregnancy with choline.

Pregnant rats fed extra doses of an essential nutrient called choline produced offspring whose brain circuits were "wired" to learn and remember far more efficiently than offspring without the supplement, according to a study at Duke University Medical Center.

Conversely, analysis of brain slices of the offspring of rats deprived of choline indicated a decrease in memory capability.

The researchers said it is the first time that a common food nutrient has been shown to cause permanent brain changes in regions responsible for learning and memory. The findings could have important implications -- especially for pregnant women and their children -- if choline proves to have the same memory-enhancing effect in humans, a theory for which considerable evidence already exists, the researchers said.

Choline is a naturally occurring amino acid found in egg yolks, milk, nuts, liver and other meats as well as in human breast milk. It is the essential building block for a memory-forming brain chemical called acetylcholine, and it plays a vital role in the formation of cell membranes throughout the body.

The Duke researchers found that brain circuits of choline-supplemented rats were built to accept and retain new information more efficiently than rats that received normal or substandard amounts of choline prenatally. And that memory enhancement endured until the rats were 4 months old -- the equivalent of early adulthood in humans.

Specifically, the research showed that choline enhanced a brain function called long-term potentiation (LTP), in which the act of receiving an electrical stimulus or "message" actually paves a pathway allowing future messages to reach the nerve cell more easily -- similar to the way that rain water creates a furrow through soil upon repeated downpours, enabling even a small trickle to find its way more easily.

If further research confirms the findings in humans, then choline could potentially be used to ensure normal memory function in the population at large through a modest change in diet, said Scott Swartzwelder, a neuropsychologist at Duke and the Durham VA Medical Center and lead author of the study. Results of his study, funded by the National Institute on Aging, will be published in the April issue of the journal of Neurophysiology.

"The ramifications of this research could be profound, because we've found that manipulating one single nutrient for a few days during gestation has a lifelong effect on brain function," Swartzwelder said. "In theory, we could develop ways to significantly reduce age-related memory deficits."

Swartzwelder said the amount of choline the pregnant rats received was well within normal limits -- about three times more than the control group received. The only time they received additional choline was during a five-day period -- days 12 through 17 -- of their 22-day gestation period. The control group received a normal dietary amount of choline, and a third group was virtually deprived of choline.

Not surprisingly, Swartzwelder said, the brains of choline-deprived rats were slower to engage the process of LTP and required a much larger stimulus to initiate LTP than the other rats.

While Swartzwelder's research is not the first to demonstrate choline's effects on memory, his is the first study reported to pinpoint the specific brain process that choline enhances.

In previous choline studies conducted at Duke, researchers showed that rats exposed to choline prenatally were better able to learn and remember the location of food in a maze, as well as to locate and swim to safety on a hidden platform in a water-filled maze. And, their memory abilities lasted well into old age. That research, conducted by Christina Williams and Warren Meck of Duke -- both co-authors of the current study -- was among the first to show that choline has a behavioral effect on memory in animals.

But until now, there has never been a physiologic explanation as to why these behavior changes occurred, said Williams, chair of the department of psychology at Duke. So, based on her behavioral studies, Swartzwelder set out to explain how choline alters memory function. By analyzing brain slices from the offspring of rats in each group, Swartzwelder showed that rats deprived of choline prenatally did not respond to even the largest electrical stimulus applied to their brain's hippocampus -- the region where LTP occurs. But the offspring of choline-supplemented animals responded very quickly and easily to the smallest electrical stimulus, indicating their hippocampus was primed to learn.

"What this suggests is an actual change in brain circuitry brought about by added choline during a critical window of prenatal development," Swartzwelder said. "The brains of choline-supplemented rats have a greater plasticity, or an ability to change and react to stimuli more readily than other rats."

Precisely why LTP occurs more readily in the choline-supplemented rats is unclear, Swartzwelder said. But there are several likely scenarios. One hypothesis is that extra choline permanently alters the developing brain circuits so they are built with either more acetylcholine receptors, or they have a greater capacity to produce acetylcholine.

A second possibility is that something inside individual nerve cells is altered to respond to acetylcholine more readily, regardless of the amount of acetylcholine present. In yet a third scenario, researchers hypothesize that there is no significant change in acetylcholine brain circuitry. Rather, choline affects a completely different neurotransmitter system, such as glutamate.

Swartzwelder said the next step is to examine the biochemistry within the various brain circuits to see which neurotransmitter systems are likely to play a role in enhancing LTP.

Source: Duke University Medical Center