Cerebral sensory development: Genetic programming versus environmental stimuli

Dec. 22, 2013 — Hiroshi Kawasaki and colleagues at Kanazawa University, Tokyo University, Tokyo Institute of Technology and Kumamoto University in Japan have identified how sensory map development is regulated in mice pups at birth, and the molecular signalling responsible.

The part of the brain associated with the sense of touch -- the somatosensory cerebral cortex -- has attracted numerous studies aimed at determining the influence of extrinsic environmental and intrinsic genetic factors in sensory development. Understanding the role of these factors in sensory map formation and development may provide insights into the mechanisms behind other circuits in the central nervous system.

Now Hiroshi Kawasaki and colleagues at Kanazawa University, Tokyo University, Tokyo Institute of Technology and Kumamoto University in Japan have identified how sensory map development is regulated in mice pups at birth, and the molecular signalling responsible.

Rodents have a sensory map in the primary somatosensory cerebral cortex, characterized by cell clusters called barrels filled with patches of nerve fibre. Inputs from the part of the brain that link to the rodent's whiskers terminate at these barrels. The barrel distribution pattern is the same as the distribution of the whiskers on the snout and forms soon after birth.

The researchers induced preterm birth in mice and quantitatively compared the degree of development of whisker-related barrel pattern formation with mice born after the full term of pregnancy. At set periods after conception, barrel formation was significantly more advanced in the mice born preterm. Further experiments ruled out the role of maternal hormones prior to birth and identified the critical effect of serotonin reductions during the days after birth.

"Interestingly, the regulatory mechanisms described here were also found to regulate eye-specific segregation in the visual system, raising the possibility that they are utilized in various brain regions," the researchers suggest. They add that further investigation of the range of roles of serotonin and the underlying mechanisms will be interesting for future research.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

---

Story Source:

The above story is based on materials provided by Organization of Frontier Science and Innovation, Kanazawa University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

---

Journal Reference:

1. Tomohisa Toda, Daigo Homma, Hirofumi Tokuoka, Itaru Hayakawa, Yukihiko Sugimoto, Hiroshi Ichinose, Hiroshi Kawasaki. Birth Regulates the Initiation of Sensory Map Formation through Serotonin Signaling. Developmental Cell, 2013; 27 (1): 32 DOI: 10.1016/j.devcel.2013.09.002

Note: If no author is given, the source is cited instead.

View the original article here

Environmental enrichment for traumatic brain injury patients may reduce shrinkage in brain

Sep. 24, 2013 — Greg Noack was 24 when he moved from Ontario to Victoria, B.C. He had just graduated from college and was looking forward to a fresh start.

One early morning in 1996, as he was returning home from his graveyard shift at the hotel, Noack was attacked from behind by a group of men.

He doesn't remember being struck on the head. He does remember waking from a 15-day coma to learn he had suffered a traumatic brain injury (TBI).

Noack, through the care of his health-care team, relearned how to walk, write, and feel particular emotions.

"I was enamoured by what my therapists were able to do for me," said Noack. "I was lucky that I got back most of my function."

Three years post-injury, Noack enrolled in Sault College's Occupational Therapist Assistant/Physical Therapist Assistant Program and graduated with honours.

Shortly after, Noack was hired by the Toronto Rehab Acquired Brain Injury Rehab team as an occupational therapist assistant and later became a rehab therapist.

Most recently, he was seconded to Dr. Robin Green's traumatic brain injury research team.

Dr. Green, Senior Scientist and Neuropsychologist, Toronto Rehab and Canada Research Chair in Traumatic Brain Injury, and her Toronto Rehab team have been studying impediments to brain injury recovery as well as treatments to offset the impediments.

Dr. Green's work suggests that moderate-severe TBI may be a progressive neurological disorder -a whole new way of perceiving the condition.

"What may be occurring after a serious brain injury," said Dr. Green, "is that damaged tissue is leaving healthy areas of the brain disconnected and under stimulated. Over time, healthy areas may deteriorate."

Importantly, they discovered that in people with chronic moderate-severe TBI, environmental enrichment -- increased physical, social and cognitive stimulation -- can offset this deterioration.

Her research paper, entitled "Environmental enrichment may protect against hippocampal atrophy in the chronic stages of traumatic brain injury," was published September 24 in Frontiers in Human Neuroscience.

In their study of 25 patients with moderate-severe TBI, her team found a positive reaction to environmental enrichment.

Those who reported greater amounts of environmental enrichment -- for example, reading, problem solving exercises, puzzles, physical activity, socializing -- at 5 months after their injury showed less shrinkage of the hippocampus (associated with memory functioning) from 5 to 28 months post-injury.

"People with moderate-severe TBI are commonly unable to return to the same level of engagement in their work, school or social lives as before the injury," said Dr. Green. "However, those with greater environmental enrichment may be keeping vulnerable areas stimulated. Environmental enrichment is also known to increase production of neurons in the hippocampus and to promote their integration into existing brain networks."

Based on the findings from their study, Green's team is now engaged in research designed to proactively offset deterioration, which includes the delivery of environmental enrichment to patients. Noack is instrumental in delivering enriched therapy for TBI patients who are enrolled in one of Dr. Green's research studies.

"One thing I loved about this study is that it facilitated greater customization of a patient's care," said Noack. "I could see how my patients benefited from the increased amount of stimulation through extended therapy."

"Although the brains of patients are showing negative changes, patients are still showing recovery of their functioning in spite of it," said Dr. Green. "If we are able to offset the negative brain changes through the treatments we are developing, we may be able to very significantly improve patients' recovery and the quality of their aging with a brain injury."

View the original article here

Obama water campaign raises environmental issue

WATERTOWN, Wis. (AP) — First lady Michelle Obama led Wisconsin high school students in a toast to "the best drink in town" Thursday as she launched a campaign to encourage people to drink more water — something she said was the single best thing Americans could do to improve their health.

"Water is so basic, and because it is so plentiful, sometimes we just forget about it amid all the ads we watch on television and all the messages we receive every day about what to eat and drink," Mrs. Obama said. "The truth is, water just gets drowned out."

The first lady launched the campaign for the nonprofit Partnership for a Healthier America in Watertown in part because the city has been recognized for the quality of its water.

While the new campaign is widely viewed as encouraging people to drink water rather than sugary sodas, partnership president and CEO Larry Soler said it is not about pushing a particular type of water or stressing it over other beverages.

Mrs. Obama has counseled people in the past to switch from soda to water and has talked about seeing improvement in her two daughters' health after making that change in their diets. She spoke Thursday about seeing her daughters become more alert after they began drinking more water, but she did not mention any switch from soda.

The first lady long ago backed away from criticism of soda because her anti-childhood obesity initiative, "Let's Move," is premised on the idea that change won't happen without buy-in from the food industry, New York University food scientist Marion Nestle said.

The latest campaign is backed by the American Beverage Association, which represents the makers of soft drinks, sports drinks, energy drinks and juices as well as bottled water, and the International Bottled Water Association.

Nestle said it actually helps the major soft drink companies, which have seen a decrease in soda sales and are investing heavily in promoting bottled water brands and other drinks, she said.

"This is a partnership with soda companies to promote their bottled waters," Nestle said.

Environmental advocates say they're disappointed the campaign ignores concerns about plastic bottles ending up in waterways and reductions in federal funding for public water systems.

"We applaud the first lady's initiative to encourage people to choose water over sugary beverages, but we do have concerns that this partnership is working in conjunction with the bottled water industry and wish that instead she were encouraging people to choose the much more affordable, more regulated option of tap water," said Emily Wurth, water program director for Food and Water Watch.

Wurth cited a federal report that found only one-fourth of plastic water bottles are recycled. She also noted that bottled water often comes from public water systems.

While Mrs. Obama did not promote tap water over bottled water, many public utility workers in Wisconsin saw her visit as an endorsement of their work. Mrs. Obama noted Watertown had been recognized as having the best-tasting water in the state — an award it received in 2010 from the Wisconsin Water Association, which represents public utilities.

"You know what you're getting with tap water because it's a regulated thing," water association vice chair Ann-Perry Witmer said. "It really is the best tasting and the healthiest for you."

Watertown, about midway between Milwaukee and Madison, is home to Wis-Pak Inc., which manufactures and distributes Pepsi-Cola products — including Aquafina. It's also home to 7-Up Bottling Co., a family-owned business that distributes bottled water and other beverages.

Soler said after the first lady's speech the campaign would be most successful by not advocating one water source over another, noting the choice of what type of water to drink lies with individuals. Mrs. Obama drank from a reusable water bottle at the launch, and the campaign includes a push for more public drinking stations.

Sam Kass, executive director of "Let's Move," has cited federal statistics showing about 40 percent of Americans drink less than half the typically recommended eight cups of water a day.

Nestle said the message that Americans don't drink enough water is questionable.

"I'm not aware of any nutrition science that backs that up ... there's so much water in food and in what people are eating that unless you're an elite athlete, at very high altitude or old where your thirst mechanism doesn't work very well, it's just simply a non-issue in my view," Nestle said.

___

Associated Press writer Darlene Superville in Washington contributed to this report.

___

Follow M.L. Johnson on Twitter at https://twitter.com/MLJohnsonOnline.

Copyright c 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

View the original article here