Weekly Neuroscience Update

Using a technique dubbed “brainbow,” the Virginia Tech Carilion Research Institute scientists tagged synaptic terminals with proteins that fluoresce different colors. The researchers thought one color, representing the single source of the many terminals, would dominate in the clusters. Instead, several different colors appeared together, intertwined but distinct. Credit: Virginia Tech.

Using a technique dubbed “brainbow,” the Virginia Tech Carilion Research Institute scientists tagged synaptic terminals with proteins that fluoresce different colors. The researchers thought one color, representing the single source of the many terminals, would dominate in the clusters. Instead, several different colors appeared together, intertwined but distinct. Image Credit: Virginia Tech.

Neuroscientists know that some connections in the brain are pruned through neural development. Function gives rise to structure, according to the textbooks. But scientists have discovered that the textbooks might be wrong. Their results were published this week in Cell Reports.

In 2011, MIT neuroscientist Rebecca Saxe and colleagues reported that in blind adults, brain regions normally dedicated to vision processing instead participate in language tasks such as speech and comprehension. Now, in a study of blind children, Saxe’s lab has found that this transformation occurs very early in life, before the age of 4. The study, appearing in the Journal of Neuroscience, suggests that the brains of young children are highly plastic, meaning that regions usually specialized for one task can adapt to new and very different roles. The findings also help to define the extent to which this type of remodeling is possible.

New research suggests individuals with autistic traits may have more advanced creativity skills than those without such traits.

Physically fit people tend to have larger brain volumes and more intact white matter than their less-fit peers. Now a new study reveals that older adults who regularly engage in moderate to vigorous physical activity have more variable brain activity at rest than those who don’t. This variability is associated with better cognitive performance, researchers say.

Young adults diagnosed with attention deficit/hyperactivity disorder (ADHD) in adolescence show differences in brain structure and perform poorly in memory tests compared to their peers, according to new research from the University of Cambridge, UK, and the University of Oulu, Finland.

People who will develop dementia may begin to lose awareness of their memory problems two to three years before the actual onset of the disease, according to a new study published in the online issue of Neurology. The study also found that several dementia-related brain changes, or pathologies, are associated with the decline in memory awareness.

People with Alzheimer’s disease have fat deposits in the brain. For the first time researchers have discovered accumulations of fat droplets in the brain of patients who died from the disease and have identified the nature of the fat.

Finally this week, a computer analyzing speech has correctly identified five individuals who would later experience a psychotic episode against 29 who would not among a group of high-risk patients in a proof-of-principle study. The findings raise the prospect of a clinical tool to aid the diagnosis and prognosis of severe mental disorders such as schizophrenia.

 

 

Weekly Neuroscience Update

Current treatment methods used are transcranial direct current simulation (tDCS) – which is application of a low intensity direct (constant) current between two electrodes on the head, and transcranial alternating current simulation (tACS) – which sees a constant electrical current flow back and forth. Image credit: Monash University.

Current treatment methods used are transcranial direct current simulation (tDCS) – which is application of a low intensity direct (constant) current between two electrodes on the head, and transcranial alternating current simulation (tACS) – which sees a constant electrical current flow back and forth. Image credit: Monash University.

Researchers have discovered a new technique to enhance brain excitability that could improve physical performance in healthy individuals such as athletes and musicians.

The constant movement of children with attention-deficit/hyperactivity disorder (ADHD) may be distracting — but the fidgeting also may improve their cognitive performance, a study has found.

It is known that sleep facilitates the formation of long-term memory in humans. In a new study, researchers show that sleep does not only help form long-term memory but also ensures access to it during times of cognitive stress.

An international team of neuroscientists has proved the uniqueness of screams for the first time. In a study, they discovered that screams possess very special acoustic properties: This makes them a specific type of vocal expression which is only used in stressful and dangerous situations.

A new study published in the journal Cerebral Cortex suggests people who speak two languages have more gray matter in the executive control region of the brain.

Structural brain abnormalities in patients with schizophrenia, providing insight into how the condition may develop and respond to treatment, have been identified in an internationally collaborative study

Memories that have been “lost” as a result of amnesia can be recalled by activating brain cells with light.

High blood levels of a growth factor known to enable new blood vessel development and brain cell protection correlate with a smaller size of brain areas key to complex thought, emotion and behavior in patients with schizophrenia, researchers report in the journal Molecular Psychiatry.

Scientists have discovered a link between autism and genetic changes in some segments of DNA that are responsible for switching on genes in the brain.

Finally this week, new research has found that types of empathy can be predicted by looking at physical differences in the brain. This raises the fascinating possibility that some kinds of empathy might be able to be increased by training or that it might be possible for people to lose their empathy over time.

Weekly Neuroscience Update

 

Brain-scan-images-by-Hospital-Sant-Pau-702x336

A new study published in the American journal with the highest impact factor in worldwide,Molecular Psychiatry, reveals that consumers of cannabis are more prone to experiencing false memories.

Excessive movement common among children with attention-deficit/hyperactivity disorder is actually vital to how they remember information and work out complex cognitive tasks, a new study shows. The findings show the longtime prevailing methods for helping children with ADHD may be misguided.

Brain scans of students from contrasting backgrounds have made visible the legacy of a challenging childhood. Important brain regions are more developed among children raised in a comfortable home environment.

New research published in the journal Nature Communications represents a potentially fundamental shift in our understanding of how nerve cells in the brain generate the energy needed to function. The study shows neurons are more independent than previously believed and this research has implications for a range of neurological disorders.

Every time you make a memory, somewhere in your brain a tiny filament reaches out from one neuron and forms an electrochemical connection to a neighbouring neuron. A team of biologists at Vanderbilt University is studying how these connections are formed at the molecular and cellular level.

Finally this week, among the advice new parents receive is to read to their babies early and often. The hope is that sharing books together will help children’s language development and eventually, turn them into successful readers. Now there is evidence that reading to young children is in fact associated with differences in brain activity supporting early reading skills.

Weekly Neuroscience Update

By using a novel technique to test brain waves, researchers are discovering how the brain processes external stimuli that do and don’t reach our awareness. Credit Beckman Institute.

By using a novel technique to test brain waves, researchers are discovering how the brain processes external stimuli that do and don’t reach our awareness. Credit Beckman Institute.

Researchers at the Beckman Institute are using a novel technique to test brain waves to see how the brain processes external stimuli that do and don’t reach our awareness. A group of international scientists has for the first time identified genetic mutations that suggest that schizophrenia and autism share underlying mechanisms. The research could help with future understanding of both conditions and may contribute to the development of treatments. Two psychologists have made a discovery that could revolutionize doctors’ perception and treatment of attention-deficit disorders. A newly identified disorder affecting the human nervous system is caused by a mutation in a gene never before implicated in human disease, according to two studies published in the journal Cell. By performing DNA sequencing of children affected by neurological problems, two research teams independently discovered that a disease marked by reduced brain size, as well as sensory and motor defects, is caused by a mutation in a gene called CLP1. Insights into this rare disorder may have important implications for the treatment of common disorders.

Scientists at the Salk Institute have created a new model of memory that explains how neurons retain select memories a few hours after an event. This new framework provides a more complete picture of how memory works, which can inform research into disorders liked Parkinson’s, Alzheimer’s, post-traumatic stress and learning disabilities.

Stanford scientists have developed faster, more energy-efficient microchips based on the human brain – 9,000 times faster and using significantly less power than a typical PC. This offers greater possibilities for advances in robotics and a new way of understanding the brain. For instance, a chip as fast and efficient as the human brain could drive prosthetic limbs with the speed and complexity of our own actions.

Finally this week, laughter triggers brain waves similar to those associated with meditation, according to a small new studyThe study included 31 people whose brain waves were monitored while they watched humorous, spiritual or distressing video clips. While watching the humorous videos, the volunteers’ brains had high levels of gamma waves, which are the same ones produced during meditation, researchers found.

 

Understanding ADHD and Learning Disability Part VII

In this final part of my series on understanding Attention Deficit/Hyperactivity Disorder (ADHD),  we delve more into the underlying mechanisms of the disorder.

Hyperactive flies can help us understand ADHD and learning disability.

Many researchers are seeking a better understanding of ADHD and the medications used to treat it by studying ADHD’s underlying mechanisms and working towards a better knowledge of this disorder.  In this video Professor David Anderson explains how our current understanding of ADHD (and the learning disability which can accompany it) as merely chemical imbalances in dopamine and noradrenaline is not working and shows that by studying a strain of hyperactive fruit fly (Drosophila) we can study the different nerve pathways involved in ADHD and learning disability which will help in providing safer and more effective treatments.

Small cold-water fish

There is no cure for ADHD at this time. However a recent (2012) study in the Journal of the American Medical Association  reports that fish consumption during pregnancy protects against ADHD in the child. In addition, many ADHD sufferers also report a beneficial effect of daily fish oil. If you are considering including fish in your diet then the study recommends small cold-water fish such as herring, mackerel, sardines and salmon rather than larger fish such as tuna which live much longer and thereby may accumulate the toxic metal mercury.

Further reading for those interested in the scientific experiments:

  1. Lebestky et al. (2009). Neuron, 64 (4), 522-36 PMID: 19945394
  2. Wang L, & Anderson DJ (2010). Nature, 463 (7278), 227-31 PMID: 19966787

Other Sources:

http://www.brainfacts.org/Diseases-Disorders/Childhood-Disorders/Articles/2012/Confronting-Attention-Deficit-Hyperactivity-Disorder

Related Reading

Part 1: Understanding ADHD and Learning Disability

Part 2: Understanding ADHD and Learning Disability

Part 3: Understanding ADHD and Learning Disability

Part 4: Understanding ADHD and Learning Disability

Part 5: Understanding ADHD and Learning Disability

Part 6: Understanding ADHD and Learning Disability

 

 

Understanding ADHD and Learning Disability Part VI: How is ADHD treated?

This is the sixth in a series on understanding Attention Deficit/Hyperactivity Disorder (ADHD).

Treatment

ADHD is commonly treated with parent education, school-based interventions, and medications such as stimulants (e.g., methylphenidate) and newer, nonstimulant drugs such as atomoxetine. Adults benefit from the same medications as children and may find some behavioural therapies helpful. On the behavioral side, children can be taught strategies for staying focused on a task such as following a detailed schedule, or for organizing materials. Adult ADHD can be a family problem as well as an individual problem. Because the symptoms of the disorder often wreak havoc on every member of the family, not just the individual with adult ADHD, it’s important for the entire group to undergo family therapy, even if the ADHD parent is already getting individual counselling. It is best to begin family therapy as soon as it becomes clear that the symptoms of adult ADHD are interfering with normal family functioning and thus avoid crises and emergencies that may take months or years to resolve. Family therapy may include teaching family members new skills and coping strategies, and therapy in which family members support and encourage each other and learn to communicate more effectively.

Drug treatment of ADHD

Many children with ADHD may also need medication. The use of stimulants to treat ADHD was first described in 1937.Since the late 1960s, stimulants such as Ritalin® or Adderall® have been prescribed to treat children with ADHD.

2011-12 shortage in U.S. market

In 2011 and 2012, there was a shortage of Ritalin® and Adderall® in U.S. pharmacies. Some say the shortage was caused by the US Drug Enforcement Administration’s (DEA) annual limits on the manufacture of controlled substances. The DEA argues that drug manufacturers had caused the shortage by applying their quotas toward more lucrative kinds of amphetamine-based medications. The shortage was resolved by November 2012. Currently, between 4 and 6 million children in the United States take one of these medications, which reduce hyperactivity and impulsivity, help improve the ability to focus, and even improve physical coordination. In fact, medications are so effective in helping people with ADHD that a recent shortage wreaked havoc for many families

Drug action

Nonetheless, there is concern about giving children a drug that is potentially addictive. Methylphenidate, the active ingredients in Ritalin®, acts like a weak form of cocaine to increase dopamine and noradrenaline levels but tend to do it all over the brain sometimes resulting in unwanted side-effects such as nervousness, drowsiness, insomnia, suspicion and paranoia. Concerta®is a slow release of methylphenidate while Daytranta® delivers the drug via a skin patch, similar to those used for nicotine replacement therapy.Adderall® is a mixture of amphetamine salts which also increase dopamine and noradrenaline levels but has a higher potential for abuse than Ritalin®.

Controversy

In addition, there is a worry that ADHD may be over-diagnosed, leading to the diagnosis and treatment of high-energy children who have difficulty in the classroom, but are medically normal. For this reason the effectiveness of treatments should be re-evaluated in each person on a regular basis to determine if the current treatment continues to be optimal. There are some reports that daily intake of fish oil can be helpful.

Related Reading

Part 1: Understanding ADHD and Learning Disability

Part 2: Understanding ADHD and Learning Disability

Part 3: Understanding ADHD and Learning Disability

Part 4: Understanding ADHD and Learning Disability

Part 5: Understanding ADHD and Learning Disability

 

 

Understanding ADHD and Learning Disability Part V: Diagnosing ADHD

This is the fifth installment in a series on understanding Attention Deficit/Hyperactivity Disorder (ADHD).  

Diagnosing ADHD – it’s harder than you think.

Currently there is no diagnostic test for ADHD. Diagnosis requires a clinical interview, parent and teacher ratings for children, and self and other ratings for adults. In addition, it is estimated that two-thirds of children diagnosed with ADHD have additional learning disorders or other mental health or neurodevelopmental conditions.   This makes it all the more important that the diagnosis is made in a multi-disciplinary environment, where the child or adult is assessed by a medical doctor, counsellor, clinical psychologist and if necessary by a psychiatrist. This is important because problems with attention can be triggered by many other conditions; in particular, adults may have attention issues along with other disorders such as depression.

….and there’s more…

Other factors have been found to affect diagnosis of ADHD. For example, the youngest children in a class are much more likely to be diagnosed as having ADHD compared to their older counterparts in the same year. This is because these children may behave more hyperactively, not because they have ADHD, but because they are younger and developmentally behind their classmates. In fact, it is estimated that about 20% of children given a diagnosis of ADHD are misdiagnosed because of the month they were born with children born in December (the youngest in class) 39% more likely to be diagnosed with ADHD than those born in January (the oldest in class).

Journal reference: http://www.ncbi.nlm.nih.gov/pubmed/22392937

Part 1: Understanding ADHD and Learning Disability

Part 2: Understanding ADHD and Learning Disability

Part 3: Understanding ADHD and Learning Disability

Part 4: Understanding ADHD and Learning Disability

 

 

 

Could there an evolutionary advantage in having ADHD?

Ariaal Elder

Ariaal Elder. The Ariaal are northern Kenyan pastoralists.

This is the fourth in a series on understanding Attention Deficit/Hyperactivity Disorder (ADHD). Today I want to examine if there is in fact an evolutionary advantage in having ADHD.

ADHD is strongly genetic and the genes involved regulate the levels of two neurotransmitters called dopamine and noradrenaline (noradrenaline is called norepinephrine in North America) – chemicals which act as messengers between nerve cells.

Hyperactivity has long been part of the human condition and some ADHD – linked genes are more common in nomadic populations and those with more of a history of migration. In fact,the health status of nomadic men such as those from the Ariaal people in northern Kenya was higher if they had an ADHD – linked gene. However, recently settled Ariaal men seemed to have slightly worse health.

ADHD – ‘the don’t fence me in’ gene

In nomadic Ariaal society,  those with ADHD may be better in tasks involving risk, competition, and/or unpredictable behavior (i.e. exploring new areas, finding new food sources, etc.). For instance, an Ariaal person killing a lion is highly respected and in these situations, ADHD would have been beneficial to the society as a whole even while severely detrimental to the individual.In addition, women in general are more attracted to males who are risk takers, thereby promoting ADHD in the gene pool. This might help explain why ADHD-linked genes have survived to the present day but are more suited to a previous nomadic, risk-taking lifestyle.

Like mother – like son

More recent research suggests that because ADHD is more common in mothers who are anxious or stressed that ADHD is a mechanism of priming the child with the necessary traits for a stressful or dangerous environment, such as increased impulsivity and explorative behaviour etc.

Journal reference: BMC Evolutionary Biology (DOI: 10.1186/1471-2148-8-173)

Part 1: Understanding ADHD and Learning Disability

Part 2: Understanding ADHD and Learning Disability

Part 3: Understanding ADHD and Learning Disability

 

 

 

What is ‘attention’ and where is it in the brain?

This is the third in a series on Understanding Attention Deficit/Hyperactivity Disorder (ADHD). Today we look closer at the nature of attentiveness and its location in the brain.

english_brainAttention is the ability of the brain to selectively concentrate on one aspect of the environment while ignoring other things. There are two types of attention in two separate regions of the brain. The prefrontal cortex (directly behind the forehead) is in charge of willful concentration; if you are studying for a test or writing a novel, the impetus and the orders come from there. But if there is a sudden, riveting event – the attack of a tiger or the scream of a child – it is the parietal cortex (behind the ear) that is activated. Scientists have learned that these two brain regions sustain concentration when the neurons emit pulses of electricity at specific rates – faster frequencies for the automatic processing of the parietal region, slower frequencies for the deliberate, intentional work of the prefrontal region.

ADHD medications increase activity in the prefrontal cortex and attention-related areas of the parietal cortex during challenging mental tasks; these are the same areas that the study I cited yesterday demonstrated to be underactive in ADHD brains. However, there may be different forms of ADHD and there is an urgent need to develop more effective drugs to regulate these two different frequencies in order to improve attention for specific forms of the disorder.

Part 1: Understanding ADHD and Learning Disability

Part 2: Understanding ADHD and Learning Disability

Understanding Attention Deficit/Hyperactivity Disorder (ADHD) Part 2

In part two of my latest series on attention deficit/hyperactivity disorder (ADHD) we take a closer look at the nature of the disorder.

These positron emission tomography (PET) scans show that patients with ADHD had lower levels of dopamine transporters in the nucleus accumbens, a part of the brain’s reward center, than control subjects.

What is attention deficit/hyperactivity disorder?

Do you remember a classmate who just could not sit still or another who just sat quietly in the corner, day dreaming and looking out the window but when called on by the teacher did not know what was going on? Today both of these children might be diagnosed with ADHD. Indeed some still argue that there is no such thing as ADHD – that it is an artificially conceived diagnosis to aid the selling of prescription drugs and that in previous times a child with ‘ADHD’ was no more than considered to be no more than ‘bored’,’ restless’ or ‘giddy’.

Prognosis

ADHD was first described more than 100 years ago and its symptoms include excessively inattentive, hyperactive, or impulsive behaviours. For instance, children with ADHD find it more difficult to focus and to complete their schoolwork. ADHD affects up to eight in one hundred children and in over half the cases, it continues to persist into adulthood.Although most individuals with ADHD do not outgrow the disorder, their symptoms often change as they grow older, with less hyperactivity as adults. Problems with attention tend to continue into adulthood. There is no cure for ADHD at this time.

Possible causes

Recent brain imaging studies have shown a reduction in the levels of the neurotransmitters dopamine and noradrenaline in at least some people with the disorder. Because the nerve circuits in the prefrontal brain regions, which are normally involved in attention, require high levels of dopamine and noradrenaline stimulation, reduced levels of these two neurotransmitters could potentially lead to the weakened regulation of attention and behavior observed in ADHD .Altered brain activity also has been observed in particular nerve circuits connecting the cortex (outer part), striatum (deeper parts), and cerebellum (back of the neck), particularly in the right brain hemisphere with a delay in cortical development seen in some children with ADHD.
In part three of this series,  I will explain more what neuroscientists mean by ‘attention’, where it is found in the brain and how it is affected in ADHD.

Other Sources:
http://www.webmd.com/add-adhd/guide/

Part 1: Understanding ADHD and Learning Disability