Durham, NC - Duke researchers have found a new type of neuron in the adult brain that is capable of telling stem cells to make more new neurons. Though the experiments are in their early stages, the finding opens the tantalizing possibility that the brain may be able to repair itself from within.

Neuroscientists have suspected for some time that the brain has some capacity to direct the manufacturing of new neurons, but it was difficult to determine where these instructions are coming from, explains Chay Kuo, M.D. Ph.D., an assistant professor of cell biology, neurobiology and pediatrics.

In a study with mice, his team found a previously unknown population of neurons within the subventricular zone (SVZ) neurogenic niche of the adult brain, adjacent to the striatum. These neurons expressed the choline acetyltransferase (ChAT) enzyme, which is required to make the neurotransmitter acetylcholine. With optogenetic tools that allowed the team to tune the firing frequency of these ChAT+ neurons up and down with laser light, they were able to see clear changes in neural stem cell proliferation in the brain.

The findings appeared as an advance online publication June 1 in the journal Nature Neuroscience.

The mature ChAT+ neuron population is just one part of an undescribed neural circuit that apparently talks to stem cells and tells them to increase new neuron production, Kuo said. Researchers don't know all the parts of the circuit yet, nor the code it's using, but by controlling ChAT+ neurons' signals Kuo and his Duke colleagues have established that these neurons are necessary and sufficient to control the production of new neurons from the SVZ niche.

"We have been working to determine how neurogenesis is sustained in the adult brain. It is very unexpected and exciting to uncover this hidden gateway, a neural circuit that can directly instruct the stem cells to make more immature neurons," said Kuo, who is also the George W. Brumley, Jr. M.D. assistant professor of developmental biology and a member of the Duke Institute for Brain Sciences. "It has been this fascinating treasure hunt that appeared to dead-end on multiple occasions!"

Kuo said this project was initiated more than five years ago when lead author Patricia Paez-Gonzalez, a postdoctoral fellow, came across neuronal processes contacting neural stem cells while studying how the SVZ niche was assembled.

The young neurons produced by these signals were destined for the olfactory bulb in rodents, as the mouse has a large amount of its brain devoted to process the sense of smell and needs these new neurons to support learning. But in humans, with a much less impressive olfactory bulb, Kuo said it's possible new neurons are produced for other brain regions. One such region may be the striatum, which mediates motor and cognitive controls between the cortex and the complex basal ganglia.

"The brain gives up prime real estate around the lateral ventricles for the SVZ niche housing these stem cells," Kuo said. "Is it some kind of factory taking orders?" Postdoctoral fellow Brent Asrican made a key observation that orders from the novel ChAT+ neurons were heard clearly by SVZ stem cells.

Studies of stroke injury in rodents have noted SVZ cells apparently migrating into the neighboring striatum. And just last month in the journal Cell, a Swedish team observed newly made control neurons called interneurons in the human striatum for the first time. They reported that interestingly in Huntington's disease patients, this area seems to lack the newborn interneurons.

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Neuron Tells Stem Cells to Grow New Neurons

MANILA, PhilippinesStem cells in a bottle? Too good to be true.

The Food and Drug Administration (FDA) has warned the public not to be taken in by the claims about Inner Power Stem Cells Booster, a purported stem cell product being sold and promoted online.

In an advisory dated May 29, FDA acting Director General Kenneth Go said the bottled product being marketed on a classified ads website, http://www.olx.ph, was not registered with the FDA either as a drug or a food supplement or human cells, tissues and cellular and tissue-based product (HCT/P).

Go also said the online ad carried deceitful health and therapeutic claims not supported by scientific or clinical studies.

According to the ad, seaweeds are the primary ingredient of the product combined with root crops, fruits, vegetables, legumes, honey and fructoligosaccharides (food for good bacteria).

The prebiotic mixture had been fermented and had produced a byproduct in the form of a jam, the ad said.

The ad further claimed that once taken, the product helped in stem cell production by the process of mitosis that would aid in platelet, red and white blood cells production.

Sea turtles

The ad also claimed that the product was formulated by a herbalist, Salvador Duco, who supposedly studied and observed the lifecycle of sea turtles.

From his study, Duco supposedly discovered that sea turtles could live up to 500 years because of the nutrients in the food they ate.

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FDA warns vs new stem cell product