Air pollution might harm brain, study says

It’s well established that dirty, sooty air is no good for your lungs and probably not great for your skin. But new research indicates it can damage your brain, too.

A study in the journal of the Archives of Internal Medicine shows that air pollution accelerates cognitive decline in women.

And with a new federal report showing Southern Californians are at the highest risk of death due to air pollution, this study adds to the growing body of grim evidence showing air pollution and healthy bodies don’t mix.

“We keep learning about more adverse effects (from pollution) than we thought possible,” said Jean Ospital, health effects officer with the South Coast Air Quality Management District, who was not involved with the current research.

“I’m not sure I find these results surprising,” he said, “but I’m also not sure I would have expected them if you’d asked me 10 years ago.”

The new research, conducted by a team of researchers from Chicago, Boston, Baltimore and Philadelphia, looked at the effect of coarse particulate matter in the air on the cognitive health of older women.

“We, as a society, are on the verge of dealing with an unprecedented number of people having dementia,” said Jennifer Weuve, lead author of the study and a researcher at Chicago’s Rush University Medical Center. “We know relatively little about how to prevent dementia, but we do know cognitive decline is related to dementia.”

Weuve pointed to research showing a link between air pollution and cardiovascular disease.

“It turns out that cardiovascular disease may play a role in cognitive decline," said Weuve, who is a researcher at Rush’s Institute for Healthy Aging. "So if we understand how to prevent or delay these cognitive increments, maybe we can prevent or delay dementia.”

And not just at an individual level, she said.

“What’s interesting about air pollution," Weuve said, is that “other factors that may cause dementia are generally found at the more individual level – diet, weight, smoking. And we can help to try to prevent them at that level. But in this case, we’re looking at something that we can do to intervene at a broad scale, with society at large."

"It's a whole new way to think about prevention for dementia and cognitive decline," she said.

Weuve and her team turned to one of the largest epidemiological datasets and cohorts in medical research, the Nurses' Health Study, to begin looking for links between pollution and cognitive health.

The Nurses' Health Study, which researchers began in 1976, is a dataset based on information collected over time from 121,700 female registered nurses between the ages of 30 and 55 living in 11 different states.

Between 1995 and 2001, Weuve and her colleagues invited participants of the Nurses' Health Study to participate in a study of cognition. The team was able to get data from nearly 20,000 women.

To establish pollutant exposure, the team collected air pollution exposure data from the Environmental Protection Agency, which they correlated with the location of each woman's home and place of employment. Then they called each woman six times on the phone, over six years, and tested their cognitive abilities.

They found that higher levels of long-term exposure to air pollution particles was associated with significantly faster cognitive decline.

She said more research needs to be done. For instance, is the cognitive decline they observed due to cardiovascular issues, or are pollutants having a direct effect on the brain?

She said more research also will be needed to confirm her work.

"The bottom line," said Sam Atwood, a spokesman for the South Coast Air Quality Management District, "is that in Southern California, we have some of the highest levels of particulate matter in the country, and we are working as quickly as possible at reducing those levels."

Falak undergoes procedure to reduce brain infection level

New Delhi, Feb 14 (PTI) Doctors at AIIMS today conducted another surgery on battered two-year-old Falak to bring down the infection level in the brain even as she continued to be in a critical but stable state. According to doctors at the AIIMS Trauma Centre who are attending on baby Falak, the surgery was conducted as an "alternative attempt" to fight brain infection. "We did a bedside procedure wherein we put a tube in the brain that drains outside instead of the spine. This has been undertaken as an attempt to bring down the infection level in her brain. Because of this infection, she continues to remain critical but stable," neurosurgeon Deepak Agarwal, who has been treating her, said. With today's procedure, Falak has undergone a total of four surgeries since her admission in the hospital on January 18. Falak was brought to the hospital on January 18 with severe head injury, both her arms broken, bite marks all over her body and her cheeks branded with hot iron. Dr Agarwal said, "With the damage she has suffered in the brain, if she survives, there are high chances that she will be mentally retarded or have a low conscious level. At present, we are trying to do our level best to get her out of the ICU." Doctors also said that she still continues to remain on ventilatory support as she cannot breathe on her own. She underwent a life saving surgery of the brain immediately after her admission here. Later on, it was followed by two more surgeries.

How our brain recognizes expressions

Researchers have identified two areas in the brain that are critical for either detecting or distinguishing emotions from facial expressions. People with damage to these areas cannot understand the wide variety of facial expressions that convey social signals, which are important foranyone trying to navigate their way in society.

Dr. Lesley Fellows, lead investigator, and her student Ami Tsuchida studied a large sample of patients with damage to various regions within the prefrontal cortex (PFC), testing to see where damage had the biggest impact on emotion recognition.

The result of their tests led to conclusions about two sub-regions of the PFC that until now had been little studied.

“Patients with damage to the ventromedial PFC had a hard time distinguishing a neutral facial expression from emotional ones,” said Dr. Fellows.

“Patients with left ventrolateral PFC damage recognized that an emotion was present in the expression, but had difficulty telling one emotion from another.

“The ability to cross-over research and clinical work enables crucial advances in science and medicine, a prime example of the benefits of The Neuro’s integrated model as a combined hospital and research institute,” Dr. Fellows added.

The research adds to our understanding of how our brains detect emotional expressions and interpret the meaning of those expressions.

The findings could help to understand some of the difficulties in social behaviour seen in neuropsychiatric illnesses including certain forms of dementia, autism, or after a traumatic brain injury.

The study has been published in the journal Cerebral Cortex. 

Child abuse leaves a long-lasting mark on brain: Study

Washington: Abuse and maltreatment during childhood can shrink important parts of the brain that could lead to psychiatric disorders like depression, drug addiction and other mental health problems later in life, according to Harvard scientists.

The link between childhood abuse and reduced brain volume in parts of the hippocampus could help find new, better ways to treat survivors of childhood abuse, the scientists said.

"These results may provide one explanation for why childhood abuse has been identified with an increased risk for drug abuse or psychosis," study researcher Martin Teicher of
Harvard University told LiveScience.

"Now that one can look at these sub-regions in the brain, we can get a better idea of what treatments are helping."

For their study, published in the journal Proceedings of the National Academies of Sciences, Teicher and his team used magnetic resonance imaging (MRI) to scan the brains of 193 individuals between 18 and 25 years old, who had already undergone several rounds of testing to be qualified.

They then analysed the size of areas in the hippocampus and compared the results with the patient`s history.

It was found that those who had been abused, neglected or maltreated -- based on well-established questionnaires – as children had reduced volume in certain areas of hippocampus by about six per cent, compared with kids who hadn`t experienced child abuse.

They also had size reductions in a related brain area, called the subiculum, which relays the signals from the hippocampus to other areas of the brain, including the dopamine system, also known as the brain`s "reward center".

Volume reduction in the subiculum has been associated with drug abuse and schizophrenia, as well.

In animal experiments, including non-human primates, this hippocampus can shrink because of high exposure to the stress hormone cortisol during two developmental periods: between ages 3 and 5 and between ages 11 and 13, the researchers said.

These stress hormone levels stop the growth of neurons in the hippocampus, leading to smaller volume in the adult human brain. Changes in hippocampus volume have been linked to depression, schizophrenia and other psychiatric disorders.



High stress levels from childhood abuse and maltreatment during important brain development periods may be causing the decreased hippocampus volume that the researchers saw.


"This region has a lot of receptors for the stress hormone cortisol. It interacts with receptors in these neurons to effect the development and the branching of these neurons,"
Teicher said. "The neurons are responding by either shrinking or not going into neurogenesis [and making new neurons]."

These brain changes can cause mental illness, explaining why childhood abuse is highly correlated to diseases like depression and drug addiction, Teicher said.

"By damaging it to some degree you may cause the dopamine system to be disregulated, and disregulation of the dopamine system has been linked to drug abuse and psychological illnesses," he added.