Weekly Update: Brain Research

Using a sling or cast after injuring an arm may cause your brain to shift quickly to adjust, according to a study published in the January 17, 2012, print issue of Neurology®. The study found increases in the size of brain areas that were compensating for the injured side, and decreases in areas that were not being used due to the cast or sling.

A  new UC Davis study shows how the brain reconfigures its connections to minimize distractions and take best advantage of our knowledge of situations.

Neuroscientists at Kessler Foundation have documented increased cerebral activation in patients with multiple sclerosis (MS) following memory retraining using the modified Story Memory Technique (mSMT).  This is the first study to demonstrate that behavioral interventions can have a positive effect on brain function in people with cognitive disability caused by MS, an important step in validating the clinical utility of cognitive rehabilitation.

A program designed to boost cognition in older adults also increased their openness to new experiences, researchers report, demonstrating for the first time that a non-drug intervention in older adults can change a personality trait once thought to be fixed throughout the lifespan.

Researchers from the Institute of Psychiatry (IoP) at King’s College London have, for the first time, identified the facial expression of anxiety. The facial expression for the emotion of anxiety comprises an environmental scanning look that appears to aid risk assessment. The research was published this week in the Journal of Personality and Social Psychology.

New research from Uppsala University, Sweden, shows that a specific brain region that contributes to a person’s appetite sensation is more activated in response to food images after one night of sleep loss than after one night of normal sleep. Poor sleep habits can therefore affect people’s risk of becoming overweight in the long run. The findings are published in the Journal of Clinical Endocrinology & Metabolism.

Teenagers are more susceptible to developing disorders like addiction and depression, according to a paper published by Pitt researchers Jan. 16 in the Proceedings of the National Academy of Sciences.

Harvard scientists have developed the fullest picture yet of how neurons in the brain interact to reinforce behaviors ranging from learning to drug use, a finding that might open the door to possible breakthroughs in the treatment of addiction.

Virtual reality-enhanced exercise, or “exergames,” combining physical exercise with computer-simulated environments and interactive videogame features, can yield a greater cognitive benefit for older adults than traditional exercise alone, according to a new study published in the February issue of the American Journal of Preventive Medicine.

Sleeping after a traumatic event might lock in bad memories and emotions, a new study has found.

A team of researchers at the MedUni Vienna’s Department of Neurophysiology (Centre for Brain Research) has discovered a previously unknown effect of opioids – that opioids not only temporarily relieve pain, but at the right dose can also erase memory traces of pain in the spinal cord and therefore eliminate a key cause of chronic pain.

 

Weekly Round Up

Image Source: The Dana Foundation

Our senses of sight and hearing work closely together, perhaps more than people realize, a new UCLA psychology study shows.

A team of neurobiologists  has shown for the first time that cortex, the largest area of the brain that is typically associated with higher functions such as perception and cognition, is also a prominent site of emotional learning.

Tiny electric currents applied across regions of the brain can improve hand movements in recovering stroke patients for a short period, an Oxford University study has demonstrated.

For the first time, scientists have proven that cannabis harms the brain. But the same study challenges previously-held assumptions about use of the drug, showing that some brain irregularities predate drug use.

How might keeping patients awake during surgery lead to the more successful removal of brain tumours? James Keidel, in his shortlisted entry for the 2011 Wellcome Trust Science Writing Prize, explains.

Researchers from the University of Bristol have discovered that a chemical compound in the brain can weaken the synaptic connections between neurons in a region of the brain important for the formation of long-term memories. The findings, published in the Journal of Neuroscience, may also provide a potential explanation for the loss of memory associated with Alzheimer’s.

Weekly Round Up

Researchers have identified the group of neurons that mediates whether light arouses us or not.

Providing support to a loved one offers benefits to the giver, not just the recipient, a new brain-imaging study by UCLA life scientists reveals.

There’s growing evidence that the brains of autistic children are very different from the brains of other youngsters. Now a new study that found an excess of brain cells in children with autism comes closer to pinpointing the origins of the condition: in utero versus in toddlerhood.

Finally this week, scientists have found a direct link between the number of ‘Facebook friends’ a person has and the size of particular brain regions. Commenting on the study, Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said: “We cannot escape the ubiquity of the internet and its impact on our lives, yet we understand little of its impact on the brain, which we know is plastic and can change over time. This new study illustrates how well-designed investigations can help us begin to understand whether or not our brains are evolving as they adapt to the challenges posed by social media.”

Stroke recovery boosted by Prozac

Stroke is the third biggest killer disease in Ireland – over 2,000 people die per year – causing more deaths than breast cancer, prostate cancer and bowel cancer combined. Up to 10,000 people will suffer a stroke in Ireland this year and one in five people will have a stroke at some time in their life.

An unexpected new finding for antidepressant drugs and a very important one.

Findings from the largest study of selective serotonin re-uptake inhibitors (SSRIs) and stroke report that giving stroke patients the antidepressant drug Prozac soon after the event helps their recovery from paralysis. A total of 118 French patients were involved in the study. The beneficial effects of the drug – more improvement in movement and greater independence – were seen after three months – helping patients gain independence. This finding suggests that this already licensed drug – also known as fluoxetine – could have a dual benefit in the treatment of acute ischemic stroke – that’s where blood flow and oxygen supply to the brain are impaired.

Antidepressant drugs can help neurons to grow

One theory about how antidepressants may help brains recover more quickly from stroke is that they encourage neurogenesis – the creation of new neurons – in particular in the hippocampus – a brain region implicated in emotion especially anxiety – an emotion which can wear down even the most resilient person.

The ability of antidepressant drugs to increase neuron growth and connections – brain plasticity – is a promising pathway for treatment of patients with ischemic stroke and moderate to severe motor deficit. It’s a controversial theory and so far it only appears to hold true in young mice. In middle-aged and older mice, no such neurogenesis was observed – so there may be another mechanisms operating. 

One thing is for sure – it’s an important finding and I hope we’ll see more work on this.

Exercise doesn’t just make you fitter – it makes you smarter too!

Exercise is important in keeping your heart and lungs healthy. We know for decades that the effort required in exercise allows life-giving oxygen to travel quicker and in greater amounts to all the tissues of the body – allowing the cells in them to grow and divide. A noticeable exception to this rule is the brain.

Neurons are different

Nerve cells or neurons are notoriously bad at dividing. Rather than divide, a neuron survives by making up to 10,000 connections to neighbouring neurons – and this is the key to how we learn and recall as memories are created and strengthened.  This compromise works well for the first four decades of life however by your 50’s a gradual loss of neurons and their connections starts to take it toll resulting in a noticeable reduction in cognition as we find it harder to remember, especially recent events. 

An unexpected finding

Recent scientific findings from Columbia University show that exercise is important in helping to reverse this age-related loss of neurons. In this study in a small group of middle-aged people, exercising just an hour a day, four times a week, for three months triggers the growth of new neurons – a feat which has previously proved almost impossible for neuroscientists to achieve using drugs. Neuroscientists are still working out the possible reasons why simple exercise is so powerful at triggering the birth of neurons but a clue may be that the brain is very well supplied by blood vessels needed to deliver the food and oxygen to help make and maintain the trillions of synapses in the brain. In fact the brain is one of the most oxygen-sensitive organs of the body. It receives 20% of the cardiac output and accounts for about 25% of overall resting oxygen consumption. In addition, the brain as a highly vascular organ is very sensitive to changes in blood perfusion. It seems the extra increase in blood perfusion and life-giving oxygen associated with exercise may invigorate the brain to such a degree that it starts to actually grow new neurons again.

Exercise is as important as drugs

The finding that exercise triggers the brain to grow new nerve cells is a truly stunning discovery that will have implications for public healthcare policies for an increasingly ageing population. In addition, new treatments for brain illness such as Alzheimer’s disease and head injury may involve a combination of different therapies such as medication, psychological therapies, social support, self-help techniques and now, most importantly exercise. This combined approach will treat the person as a whole, and marks the beginning of the journey back to wellness and a normal life.

So the message is simple –if you want to stay smart just get out there and exercise.

Latest research from computational neuroscience

Another fascinating topic from the SFN Annual Meeting was the research being undertaken in the area of computational neuroscience.

Computational neuroscience is the study of brain function in terms of the information processing properties of the structures that make up the nervous system.

It is an interdisciplinary science that links the diverse fields of neuroscience, cognitive science and psychology with electrical engineering, computer science, mathematics and physics.

In an interview in the current edition of New Scientist, Professor Terry Sejnowski, head of the computational neurobiology lab at the Salk Institute in La Jolla, California, says some of the most intriguing results in computational neuroscience come from collaborations between modelers and experimentalists.

Professor Sejnowski and his research colleagues’ research in modeling signal transfer patterns throughout the brain has resulted in new techniques which make it possible to simultaneously record signals from many neurons. The sensitivity means scientists can for the first time, watch the output from a neuron spread through the brain.

Research has also found that neurons respond differently to different stimuli (for example, signals required to move a prosthetic arm can change when people are tired). This research will help improve brain-machine interferences such as prosthetic limbs and thought-controlled wheelchairs.