Scientists investigate role of stem cells in adult brain cell production

Feb 16, 2009
Procambarus clarkii

(PhysOrg.com) -- Georgia State researchers in the university’s Neuroscience Institute and the department of biology are investigating how stem cells create new brain cells in adulthood.

The scientists are looking at how new neurons — the basic cellular elements of the nervous system — are made during a process called neurogenesis in a species of crayfish called Procambarus clarkii.

“To drive the permanent production of cells in any given tissue, you need stem cells to support it,” said Manfred Schmidt, a Georgia State research scientist who led the project that was performed in the labs of professors Don Edwards and Charles Derby, mainly by Cha-Kyong Song, a graduate student and Laurel M. Johnstone, a research technician.

Decades ago, scientists believed that addition of new neurons stopped at adulthood, but they now recognize that neurogenesis continues, for both crustaceans and mammals alike. It continues because neuronal stem cells, which create different types of brain cells, continue to exist into adulthood, though not in as great of numbers as in embryos.

Neuronal stem cells take different forms depending on the type of animal. In crustaceans, relatively large cells called neuroblasts are responsible for neurogenesis, located in a part of the brain responsible for processing odor information, called the olfactory midbrain.

In other crustaceans, the neuroblasts are located near to where the new neurons are generally located. But Schmidt and his colleagues found that the neuroblasts in crayfish brains are located farther from where the new neurons are needed — forcing them to travel down pathways to get to their destinations.

“In essence, these are similar organisms, except the stem cells are further away from the action,” Schmidt said. “Now you have to ship out the cells that the stem cells are producing, through a long path to finally reach their target.”

Schmidt said this might be due to the way crayfish have evolved to live in freshwater environments, rather than in saltwater.

“That is a big evolutionary step, and in making this step, they might have lost some of their olfactory capacity,” he explained.
In order for stem cells — legacies of embryonic development — to live in adult body tissues, the cells need particular areas that are suitable environments for them to live, or niches. In crayfish, the niches surrounding neuroblasts are unique structures that can be distinctly identified as being clumps of cells associated with the stem cells.

“It seems that the mechanism of making a neuron in an adult animal is an extension of how this is done in the embryo,” Schmidt said, adding that he and other researchers hope to better understand these niches and how they support stem cells throughout adult life.

Provided by Georgia State University

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

add to favorites email to friend print save as pdf

Related Stories

Comcast wins more Internet customers, ad sales up

51 minutes ago

Comcast Corp.'s third-quarter net income jumped 50 percent in the third quarter, helped by a one-time tax settlement, growth in Internet subscribers and fewer defectors from its cable service.

Helping sweet cherries survive the long haul

56 minutes ago

A new study says that cherry producers need to understand new intricacies of the production-harvest-marketing continuum in order to successfully move sweet cherries from growers to end consumers. For example, the Canadian ...

Christian Bale to play Apple's Steve Jobs

1 hour ago

Oscar-winner Christian Bale—best known for his star turn as Batman in the blockbuster "Dark Knight" films—will play Apple co-founder Steve Jobs in an upcoming biopic.

Netflix to stream new online TV series, 'Bloodline'

1 hour ago

Fresh from commercial and critical success with hit shows "House of Cards" and "Orange is the New Black," Netflix on Thursday announced a new online series, "Bloodline," set for release in March.

YEATS protein potential therapeutic target for cancer

1 hour ago

Federal Express and UPS are no match for the human body when it comes to distribution. There exists in cancer biology an impressive packaging and delivery system that influences whether your body will develop cancer or not.

Recommended for you

Cat dentals fill you with dread?

Oct 24, 2014

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity ...

User comments : 0