Drugs, Addiction and the Brain

alcohol-addiction-brain-scan

I will be giving a talk on drugs, addiction and the brain for alcohol and drug awareness week  which is scheduled to take place November 17th – 21st 2014.

This talk will explain how the brain basically works and how and where drugs such as heroin, cocaine, alcohol and cannabis work in the brain. The concept of “reward” which is the property that is characteristic of many addictive drugs will also be discussed. The talk will be useful for those interested in learning about the diverse effects of drugs of abuse on the brain.

Details: Wednesday 19th November 7-9 pm at the Absolute Hotel, Limerick– Abbey Suite 3. Free Admission.

Weekly Neuroscience Update

neuronal-heat-maps-in-brain

Scientists at CSHL have developed a new mathematical model that makes predictions about where different types are neurons are located throughout the brain. Here are “heat maps” of the brain, made using the mathematical model to predict the distribution of different neurons. Each row represents one neuronal type, and different sections of the brain are shown in each column. Color indicates the likelihood of a particular neuronal type appearing in that area of the brain (white, most likely; black, least). Credit Mitra et al.

A new mathematical model uses gene expression data to predict where neurons are located throughout the brain.

Researchers have studied the acquisition and development of language in babies on the basis of the temporary coordination of gestures and speech. The results are the first in showing how and when they acquire the pattern of coordination between the two elements which allows them to communicate very early on.

The problems people with autism have with memory formation, higher-level thinking and social interactions may be partially attributable to the activity of receptors inside brain cells, researchers have learned.

A new study documents the brain activity underlying our strong tendency to infer a structure of context and rules when learning new tasks (even when a structure isn’t valid). The findings, which revealed individual differences, shows how we try to apply task knowledge to similar situations and could inform future research on learning disabilities.

Researchers have discovered impaired neuronal activity in the parts of the brain associated with anticipatory functioning among occasional 18- to 24-year-old users of stimulant drugs, such as cocaine, amphetamines and prescription drugs such as Adderall.

Why do some teenagers start smoking or experimenting with drugs — while others don’t? In the largest imaging study of the human brain ever conducted — involving 1,896 14-year-olds — scientists have discovered a number of previously unknown networks that go a long way toward an answer.

New research shows that, contrary to what was previously assumed, suppressing unwanted memories reduces their influence on behaviour, and sheds light on how this process happens in the brain.

For our brain, animate and inanimate objects belong to different categories and any information about them is stored and processed by different networks. A study shows that there is also another category that is functionally distinct from the others, namely, the category of “social” groups.

A new technique provides a method to noninvasively measure human neural networks in order to characterize how they form.

Education significantly improves mental functioning in seniors even four decades after finishing school, shows a new study. The study shows that people who attended school for longer periods performed better in terms of cognitive functioning than those who did not.

 

Top ten blog posts of 2013

Top-10-ListThese were the most popular blog posts on Inside the Brain ranked according to most page views in 2013.

Does Addiction Exist?

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

Understanding ADHD and Learning Disability

Understanding ADHD and Learning Disability Part V: Diagnosing ADHD

Could there an evolutionary advantage in having ADHD?

What can mirror neurons teach us about consciousness, mental health and well-being?

Inside The Musical Brain

This Is Your Brain On Poetry

Why Parkinson’s Disease Has Robbed Linda Ronstadt Of Her Singing Voice

How Did Tolerance Kill Cory Monteith?

Weekly Neuroscience Update

Overly connected: Many pairs of brain regions — including those involved in sensory processing, emotion and motivation — are more tightly synchronized in children with autism (right) than in controls (left).

Overly connected: Many pairs of brain regions — including those involved in sensory processing, emotion and motivation — are more tightly synchronized in children with autism (right) than in controls (left).

Three studies published over the past two months have found significant evidence that children and adolescents with autism have brains that are overly connected compared with the brains of controls. The findings complicate the theory that autism is fundamentally characterized by weakly connected brain regions. Meanwhile new findings suggest the oxytocin receptor, a gene known to influence mother-infant bonding and pair bonding in monogamous species, also plays a special role in the ability to remember faces. This research has important implications for disorders in which social information processing is disrupted, including autism spectrum disorder. In addition, the finding may lead to new strategies for improving social cognition in several psychiatric disorders.

Researchers are gaining a better understanding of the neurochemical basis of addiction with a new technology called optogenetics.

We know that getting even a measly extra hour of sleep a night can have major benefits for us–like more memories, less anxiety, and happier genes. But scientists have tested another hypothesis for why we need to spend so much time horizontal: Sleep cleans our brains.

Scientists have pinpointed a specific part of the brain where Alzheimer’s begins and traced how the disease spreads.

Scientists have zapped an electrical current to people’s brains to erase distressing memories, part of an ambitious quest to better treat ailments such as mental trauma, psychiatric disorders and drug addiction.

Finally this week, many people can recall reading at least one cherished story that they say changed their life. Now researchers at Emory University have detected what may be biological traces related to this feeling: Actual changes in the brain that linger, at least for a few days, after reading a novel.

Does Addiction Exist?

Addiction (1)American actor and addiction-awareness activist Matthew Perry and journalist Peter Hitchens traded blows in a televised interview last week,  with the latter questioning the reality of drug addiction. Hitchens questions how Perry has suffered in his ‘battle with addiction’ and for his motives in supporting special courts for people who buy and use illegal drugs.  Hitchens has gone further to question if in fact ‘addiction’ actually exists at all.  Not surprisingly this has resulted in one hell of a row.

Over the past two decades I have visited high schools and colleges to talk on how addictive drugs affect the brain and to explain the many theories about why certain people become addicted.

What is an addictive drug?

All addictive drugs release the neurotransmitter dopamine in the brain and this is thought to contribute to their addictive properties. Dopamine is carried in a nerve pathway called the reward pathway which controls the brain’s reward and pleasure centers. The reward pathway does this by regulating emotional responses that enable us not only to see rewards but also to take action to move toward them.  Addictive drugs hijack the reward pathway by causing it to release dopamine and this leads to the compulsive behavior including the loss of control in limiting intake found in addiction.

Are some drugs more addictive than others?

Yes. The type of drug taken is important as some drugs are more addictive than others.  This is because drugs differ in their ability to release dopamine in the reward pathway.  How a drug is taken is also very important. Nicotine is very addictive because it is smoked.  Smoking is the quickest way to get a substance into the brain and this makes it more addictive.

Don’t forget the buzz

The initial use of addictive drugs such as cocaine, heroin, alcohol and marijuana is often driven by the immediate euphoria – the buzz – that accompanies it and because their brains are so rich in dopamine this is of great importance to adolescents and young adults.  In this way drug addiction is predominantly a disease of the young.

Why do people take addictive drugs?

People dabble in addictive drugs for all sorts of reasons  – availability, affluence, to rebel, to seek attention, for a sense of adventure, naivety, the pressure to conform  or just plain boredom.

Who becomes an addict?

Addiction is complex and there are as many reasons why someone becomes addicted as there are addicts. This situation is not helped by the fact that we cannot yet predict who will become addicted, or how to cure it.

Addiction is a three-legged stool

The problem is that not everyone who takes addictive drugs becomes addicted. In fact, most drug users can with a little effort, drop their habit.  In order to explain who becomes addicted it is best to think of addiction as a three-legged stool and just as a stool needs all three legs in place- all three legs must also be in place for addiction to take hold. The three legs of addiction are

  • Biological.  For instance, children of alcoholics are four times more likely to become addicted to drink, even if they’re brought up away from their natural parents.
  • Psychological.  For instance, chronic, inescapable stress including the stress of boredom contributes to addictive behavior.
  • Social.  For instance, the availability of a drug is important – it’s harder to become an alcoholic in Saudi Arabia where the sale of alcohol is forbidden.

Hitchens is right – addiction doesn’t exist – that is, until you become an addict.

So, in one way Hitchens is right- addiction doesn’t exist – that is, until you become an addict. Then it controls your every waking and sleeping moment, it can destroy your life and those of your loved ones, shatter talent and ambition, wreck communities and economies.

Drug taking as a way of coping

The row between Perry and Hitchens over the nature of addiction might not be in vain if it opens up a debate on how we as a society deal with stress. We all know of, or have heard of someone suffering from chronic addiction and we are led to surmise that alcohol and drug taking is their way of coping.  In this we are not alone. As the world economy continues on its downward slide, and unemployment and financial worries beset us, are we going to turn more and more to these quick fixes to handle our dis-stress?

Probably the most important lesson to be taken from this row is the realization that the stresses of life and how we manage them IS the difference between life and death. I look forward to developing this theme in greater detail including drug-free tips on how to avoid worry and stress in future posts, but in the meantime, I salute both Perry and Hitchens for bringing addiction back into the spotlight.

Weekly Neuroscience Update

3D-printed model of a neuron (credit: Yale University)

3D-printed model of a neuron (credit: Yale University)

A Yale neuroscientist  has created the first 3D-printed neuron.

Studies released today suggest promising new treatments for nicotine and heroin addiction, and further our understanding of pathological gambling and heroin abuse in those suffering chronic pain. This new knowledge, released at Neuroscience 2013, the annual meeting of the Society for Neuroscience (SFN) and the world’s largest source of emerging news about brain science and health, may one day lead to non-pharmaceutical interventions and therapies to treat addiction. Also presented at SFN, new studies revealing links between social status and specific brain structures and activity, particularly in the context of social stress.

A new study has found that people experiencing a depressive episode process information about themselves differently than people who are not depressed.

To flexibly deal with our ever-changing world, we need to learn from both the negative and positive consequences of our behaviour. In other words, from punishment and reward. Hanneke den Ouden from the Donders Institute in Nijmegen demonstrated that serotonin and dopamine related genes influence how we base our choices on past punishments or rewards. This influence depends on which gene variant you inherited from your parents. These results were published in Neuron on November 20.

Brain scans reveal that people with fibromyalgia are not as able to prepare for pain as healthy people, and they are less likely to respond to the promise of pain relief.

Scientists have used RNA interference (RNAi) technology to reveal dozens of genes which may represent new therapeutic targets for treating Parkinson’s disease. The findings also may be relevant to several diseases caused by damage to mitochondria, the biological power plants found in cells throughout the body.

Playing a fast-paced strategy video games can help the brain to become more agile and improve strategic thinking, according to new research.

While young children sleep, connections between the left and the right hemispheres of their brain strengthen, which may help brain functions mature, according to a new study by the University of Colorado Boulder.  And in another sleep study, a team of sleep researchers  has confirmed the mechanism that enables the brain to consolidate memory and found that a commonly prescribed sleep aid enhances the process. Those discoveries could lead to new sleep therapies that will improve memory for aging adults and those with dementia, Alzheimer’s and schizophrenia.

Weekly Neuroscience Update

To study how nerve cells respond to injuries in their branches, Washington University researcher Valeria Cavalli grows them in “spots” like the one shown above. Cavalli recently identified a chain reaction that enables repair of these branches when they are cut. Credit Yongcheol Cho/Washington University at St. Louis.

To study how nerve cells respond to injuries in their branches, Washington University researcher Valeria Cavalli grows them in “spots” like the one shown above. Cavalli recently identified a chain reaction that enables repair of these branches when they are cut. Credit Yongcheol Cho/Washington University at St. Louis.

Researchers have identified a chain reaction that triggers the regrowth of some damaged nerve cell branches, a discovery that one day may help improve treatments for nerve injuries that can cause loss of sensation or paralysis.

Groundbreaking research nearly two decades ago linking a mother’s educational background to her children’s literacy and cognitive abilities stands out among decades of social science studies demonstrating the adverse effects of poverty. Now new research has taken that finding in a neuroscientific direction: linking poor processing of auditory information in the adolescent brain to a lower maternal educational background.

A review of new research says there is growing evidence to support the idea that the brain plays a key role in normal glucose regulation and the development of type 2 diabetes.

University of Queensland (UQ) scientists have made a fundamental breakthrough into how the brain decodes the visual world.

Cocaine addicts may become trapped in drug binges not because they are always seeking euphoric highs but rather to avoid emotional lows, says a study in Psychopharmacology.

Researchers have developed a therapeutic at-home gaming program for stroke patients who experience motor weakness affecting 80 percent of survivors.

Learning a musical instrument as a child gives the brain a boost that lasts long into adult life, say scientists.

The birth of new neurons depend upon activation of an important molecular pathway in stem cells, a new Yale School of Medicine study shows.

Researchers have taken a major step towards understanding the causes of Alzheimer’s disease with the largest study yet into the genetics of the disorder.

Light enhances brain activity during a cognitive task even in some people who are totally blind, according to a new study.

Scientists have discovered biological mechanisms that may link Parkinson’s disease to Alzheimer’s disease, according to a study published in the journal Acta Neuropathologica.

 

How Did Tolerance Kill Cory Monteith?

Corey M

I was saddened this week to read of the coroner’s verdict on the death of Cory Monteith.  The 31-year-old talented actor and performer had been plagued by substance abuse problems long before his Hollywood days and had voluntarily checked himself into rehab in March where he completed a 30-day program.

Heroin and alcohol – a potentially lethal mix

Over the past two decades I have visited high schools and colleges to talk on how addictive drugs including heroin and alcohol affect the brain and it still amazes me how little the general public understand how these potentially lethal drugs work.

The post mortem showed the Cory’s death was due to a combination of heroin and alcohol intake. Both heroin and alcohol have similar effects on the brain. They both elevate mood, lower heart rate and put your brain into a sleepy inattentive state.  Heroin and alcohol are what’s called narcotics (i.e. sleep inducers) and sometimes called nervous system depressants – not to be confused with a depressed mood but relating as to how these drugs act to silence (i.e. depress) activity in the nervous system.  It is no coincidence then that a street name for heroin is dope. Once in the brain, heroin is converted to morphine by enzymes and the morphine binds to opiate receptors in certain areas of the brain. Alcohol in contrast, acts in a less specific way by making neurons ‘leaky’.  Both drugs are highly addictive and to make matters worse, at high enough doses they  both can act as anaesthetics – drugs that switch off important nervous functions in the brain stem – like for instance, respiration (breathing) and it was the combined effect of both of these drugs  in slowing and eventually stopping breathing which was why Cory died.

Many addiction experts were not surprised

It is clear from reading newspaper reports that although Cory Monteith’s friends and loved ones are deeply shocked by the revelations of the inquest many addiction experts were not surprised.  Corey struggled with drugs since he was 13 – so long in fact that his chronic addiction was hardwired into his brain. Thus, 30 days in rehab was not enough time to get to the root cause of the addiction especially if there were any underlying psychiatric issues. Brain rewiring for chronic addiction usually takes between 90 and 120 days to be effective.  Alarm bells should also have rung after he was released from rehab when he went on vacation to Mexico.  A vacation was a huge post-rehab mistake as a structured, supportive environment is so important to grow, maintain and strengthen the new brain connections.

What is tolerance and how did it kill Cory?

Not everyone who takes heroin and alcohol together dies; so what is so special about Cory’s situation? Cory died because of a brain phenomenon called tolerance. When drugs such as heroin are used repeatedly over time, tolerance may develop.  Tolerance occurs when the person no longer responds to the drug in the way that person initially responded.  Stated another way, it takes a higher dose of the drug to achieve the same level of response achieved initially.  So for example, in the case of heroin, morphine and alcohol tolerance develops rapidly to the effects of the drug.  The development of tolerance is not addiction, although many drugs that produce tolerance also have addictive potential.  Tolerance to drugs can be produced by several different mechanisms, but in the case of heroin, morphine and alcohol tolerance develops at the level of biochemical reactions mainly within the liver whereby  enzymes adapt so that the drug can no longer cause changes in brain cell firing. Thus, the effect of a given dose of heroin, morphine and/or alcohol is diminished.

A decrease in tolerance after rehab put Cory’s brain at risk

During the 30 days in rehab Cory’s body gradually rid itself of drugs and tolerance also gradually faded. The reasons why Cory’s death occurred shortly after his release from rehab was because of a large decrease in tolerance that his body experienced after that period of abstinence. Thus, when Cory returned to using, he ran the risk of experiencing a far more extreme reaction to the same drug doses that he was once accustomed to using.

It is particularly sad that our memories of this genuinely loved and popular person may be tarnished by the revelation. I would urge people not to let this be the case, and to remember Corey for his talent and not the sordid nature of his death.

Drug taking as a way of coping

I do think however that Cory’s death might not be in vain if it opens up a debate on how we as a society deal with stress. We have heard that Cory had a history of chronic addiction and we are led to surmise that alcohol and drug taking was his way of coping. In this he is not alone. As the world economy continues on its downward slide, and unemployment and financial worries beset us, are we going to turn more and more to these quick fixes to handle our dis-stress?

Probably the most important lesson to be taken from Cory’s death is the realization that the stresses of life and how we manage them IS the difference between life and death. I look forward to developing this theme in greater detail including drug-free tips on how the avoid worry and stress in future posts, but in the meantime, my deepest sympathy goes to Cory’s loved ones at this difficult time.

Weekly Neuroscience Update

Getting a grip—literally— by clenching your right fist before remembering information and your left when you want to remember it can boost your recall, according to the latest study. This strange trick may work because clenching your hands activates the side of the brain that handles the function— in right-handed people, for instance, the left side of the brain is primarily responsible for encoding information and the right for recalling memory. (If you are left-handed, the opposite applies).

Mathematicians from Queen Mary, University of London will bring researchers one-step closer to understanding how the structure of the brain relates to its function in two recently published studies.

Greater adherence to a Mediterranean diet (MeD) is associated with a lower likelihood of incident cognitive impairment (ICI), especially among those without diabetes, according to a study published in the April 30 issue of Neurology.

The widespread belief that dopamine regulates pleasure could go down in history with the latest research results on the role of this neurotransmitter. Researchers have proved that it regulates motivation, causing individuals to initiate and persevere to obtain something either positive or negative.

Supposedly ‘primitive’ reflexes may involve more sophisticated brain function than previously thought, according to researchers at Imperial College London.

The production of a certain kind of brain cell that had been considered an impediment to healing may actually be needed to staunch bleeding and promote repair after a stroke or head trauma, researchers at Duke Medicine report.

For any addiction, external  cues and stress can trigger  cravings that are hard to resist, and the latest research points to an area of  the brain that might be responsible  for sabotaging recovery.