Regular aerobic exercise keeps the brain healthy

Washington, Apr 27 (ANI): Regular aerobic exercise improves blood flow to the brain and speeds learning process, says a new study.

The study led by researchers from the University of Pittsburgh School of Medicine is the first to examine these relationships in a non-human primate model.

The finding is available in the journal Neuroscience.

While there is ample evidence of the beneficial effects of exercise on cognition in other animal models, such as the rat, it has been unclear whether the same holds true for people, said senior author Judy L. Cameron, Ph.D., a psychiatry professor at Pitt School of Medicine and a senior scientist at the Oregon National Primate Research Center at Oregon Health and Science University. Testing the hypothesis in monkeys can provide information that is more comparable to human physiology.

“We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain”s motor cortex than their sedentary counterparts,” Dr. Cameron said. “This suggests people who exercise are getting similar benefits.”

To reach the conclusion, researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months. Another group of monkeys remained sedentary, meaning they sat on the immobile treadmill, for a comparable time. Half of the runners went through a three-month sedentary period after the exercise period. In all groups, half of the monkeys were middle aged (10 to 12 years old) and the others were more mature (15 to 17 years old). Initially, the middle-aged monkeys were in better shape than their older counterparts, but with exercise, all the runners became more fit.

During the fifth week of exercise training, standardized cognitive testing was initiated and then performed five days per week until week 24. In a preliminary task, the monkeys learned that by lifting a cover off a small well in the testing tray, they could have the food reward that lay within it. In a spatial delay task, a researcher placed a food reward in one of two wells and covered both wells in full view of the monkey. A screen was lowered to block the animal”s view for a second, and then raised again. If the monkey displaced the correct cover, she got the treat. After reliably succeeding at this task, monkeys that correctly moved the designated one of two different objects placed over side-by-side wells got the food reward that lay within it.

“Monkeys that exercised learned to remove the well covers twice as quickly as control animals,” Dr. Cameron said. “Also, they were more engaged in the tasks and made more attempts to get the rewards, but they also made more mistakes.”

She noted that later in the testing period, learning rate and performance was similar among the groups, which could mean that practice at the task will eventually overshadow the impact of exercise on cognitive function.

When the researchers examined tissue samples from the brain”s motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. But those blood flow changes reversed in monkeys that were sedentary after exercising for five months.

“These findings indicate that aerobic exercise at the recommended levels can have meaningful, beneficial effects on the brain,” Dr. Cameron said. “It supports the notion that working out is good for people in many, many ways.” (ANI)

Two key brain regions work in tandem like integrated network

Washington, Apr 20 (ANI): Two important areas in the central nervous system— basal ganglia and the cerebellum—are linked together to form an integrated functional network, say researchers at the University of Pittsburgh.

Each subcortical structure houses a unique learning mechanism.

It is believed that the basal ganglia circuits are involved in reward-driven learning and the gradual formation of habits.

On the other hand, cerebellar circuits are thought to contribute to more rapid and plastic learning in response to errors in performance.

“The basal ganglia and the cerebellum are two major subcortical structures that receive input from and send output to the cerebral cortex to influence movement and cognition,” explained senior author Dr. Peter L. Strick, professor of neurobiology and co-director of the Center for the Neural Basis of Cognition, Pitt School of Medicine.

“In the past, these two learning mechanisms were viewed as entirely separate, and we wondered how signals from the two were integrated. Using a unique method for revealing chains of synaptically linked neurons, we have demonstrated that the cerebellum and basal ganglia are actually interconnected and communicate with each other,” said Strick.

The finding not only has important implications for the normal control of movement and cognition, but it also helps to explain some puzzling findings from patients with basal ganglia disorders.

“Our findings provide a neural basis for these findings. In essence, the pathways that we have discovered may enable abnormal signals from the basal ganglia to disrupt cerebellar function. The alterations in cerebellar function are likely to contribute to the disabling symptoms of basal ganglia disorders. Thus, a new approach for treating these symptoms might be to attempt to normalize cerebellar activity,” said Strick.

The findings are available online this week in the Proceedings of the National Academy of Sciences. (ANI)

Experimental vaccine may delay bowel inflammation and colon cancer

Washington, March 25 (ANI): A new experimental vaccine could delay bowel inflammation and colon cancer, researchers at the University of Pittsburgh School of Medicine say.

Their findings have appeared in Cancer Prevention Research, a journal of the American Association for Cancer Research.

According to senior author Olivera Finn, professor and chair, Department of Immunology, Pitt School of Medicine, people with chronic inflammatory disorders such as IBD are at greater risk for developing cancer at the inflamed site. In other cases, genes that develop cancerous changes can trigger inflammation.

The vaccine made by her team is directed against an abnormal variant of a self-made cell protein called MUC1, which is altered and produced in excess in both IBD and colon cancer.

Dr. Finn said: “Our experiments indicate that boosting the immune response against this protein early in the disease can delay IBD development, control inflammation and thereby reduce the risk of future cancers.

“These findings suggest also that the early stages of chronic inflammation might be considered a premalignant condition.”

For the study, the scientists tested transgenic mice that spontaneously develop IBD and then progress to colitis-associated colon cancer, producing the human version of MUC1 in both disease states. It was seen that animals that received the vaccine showed the first signs of IBD significantly later than those in two control groups that did not get the vaccine.

Microscopic evaluation of the colon tissue demonstrated less inflammation in the vaccinated mice, and no indication of cancerous changes. Nearly half of the animals in each of the control groups had evidence of abnormal tissue, and two had colon cancer.

Dr. Finn said: “The MUC1 vaccine seems to change the local environment from one that promotes cancer development to one that inhibits it.

“Certain immune cells that we usually see in the inflamed colon aren”t present, and that could make the surroundings less friendly for potentially cancerous cells that also are directly targeted by the vaccine for destruction.” (ANI)