What is a headache?

We all know the feeling after a long stressful day, when the tensions of the past few 415px Tension headache 150x150 What is a headache?hours begin to amass in your temples, perhaps starting as a dull throb before advancing in waves to a deep pounding ache. The headache is a common malady, but what mechanisms lay behind these debilitating pains and which aspects of your life may be triggering them?

The question of why and how we experience headaches is significantly harder to answer than you might imagine. Particularly since the term ‘headache’ is in itself non-specific, being a broad term used to describe a range of common head pains, each of which may stem from a different underlying cause. Interestingly, however, one thing we do know is that the pain you experience during a headache does not originate from the brain itself. Indeed, the brain lacks pain receptors (nociceptors), therefore does not have the capacity to feel pain.

543px Gray507 150x150 What is a headache?But then where does the pain of a headache come from? The pain we experience during an everyday headache originates in pain-sensitive structures surrounding the skull. These include; the extracranial arteries, veins, cranial and spinal nerves, neck and pericranial muscles – all of which express pain receptors and are therefore susceptible to these sensations.

It is possible to pin down a number of simple lifestyle factors which commonly contribute to the development of headaches. These include; emotional disturbances, stress and mental tension, certain types of food, alcohol, cigarette smoke, exercise and even the way you wear your hair – hair-dos (including the tight ponytail, braids, headbands and even tight hats) can strain the connective tissue that lies across the scalp and cause headaches. So simply letting your hair down can relieve this pressure and thus the pain of the headache.

A number of the factors which lead to headaches (including certain foods, cigarette smoke and alcohol) involve the blood vessels which lie around the brain. For example, inhaling nicotine from cigarette smoke causes narrowing of blood vessels around the skull. Narrowing of these vessels can often induce extremely painful headaches. Changes in blood pressure also explain hangover and exercise headaches and why, for some people, certain foods can act as headache triggers.

6708719835 b2f15fc2e3 150x150 What is a headache?The episodic tension headache (the type you may get after a long day at work) is the most commonly occurring type of headache. However despite the extensive research into the cause of migraines, this common type of headache remains one of the least investigated. As relief can normally be sought through over-the counter painkillers, most sufferers will not consult a doctor. The mechanisms underlying what specifically causes these headaches remains elusive, however, a number of theories regarding their pathophysiology have been proposed:

It appears that the occurrence of headaches are commonly linked to general problems of the musculoskeletal system. Skeletal muscle constitutes the largest muscle mass of the body, controlling movement, breathing, facial expressions and numerous other normal physiological functions. Each individual skeletal muscle is composed of hundreds of cells, arranged in muscle fibres. Each muscle fibre is connected to the nervous system via interactions with a single branch (an axon) of a nerve cell.

Each fibre of a muscle can relax or contract in response to signals sent from the brain via these nerves. These muscle fibres also contain sensory receptors which can feedback the health of the muscle to the brain. This helps tell you when the muscle is tired or overstretched for example. Abnormal activity in these nerves, perhaps as a consequence of injury, stress or poor posture, can therefore result in the relay of pain signals to the brain. For example, bad posture places abnormal pressure on the muscles of the neck which can result in heightened tension and the subsequent development of ‘tension headaches’.

Interestingly, tension headaches can also be induced by activation of so-called ‘trigger points’. A trigger point is defined as ‘a hypersensitive area of the body, associated with taut bands within a skeletal muscle’. Pressure or compression on these localized trigger points can cause the referral of pain along linked nerves to a nearby area. So, the presence of active trigger points in your head, neck and shoulder muscles can refer pain that will be subsequently experienced as a headache.

A number of studies have confirmed this, identifying an increased number of trigger points in the muscles of the head in patients prone to headaches, compared with patients who do not regularly experience headaches. What causes these trigger points to develop in the first place still remains unclear, however, some have speculated that they may be associated with past muscular injuries, fatigue, diet and even as a result of chronic repetitive strain, such as persistent typing.

5621720708 3e3b9c45c1 150x150 What is a headache?Infrequent headaches, while menacing, are nothing compared to their chronic cousins. Infrequent headaches can become chronic as a result of changes that originate in the brain and spinal cord. This involves so called ‘second-order’ nerve cells which act as connectors between peripheral organs (e.g. the skin and muscles) and nerve cells in the spinal cord and brain.

A number of studies have proposed that chronic tension headaches may be triggered by changes in the sensitivity of these second order nerves, particularly those in the spinal cord and an area of the brain known as the trigeminal nucleus. This process is known as ‘central sensitization’ and can alter pain thresholds and trigger nerve cell activity. It is hypothesized that, in the presence of persistent stress or pain signals from peripheral muscles (such as that brought about through regular bad posture), nerve cells can grow forming new connections and effective contacts to low-threshold nerves that do not normally signal for pain. Furthermore, increased sensitivity can be caused by the enhanced release of chemicals that facilitate nerve cell communication. This increase in the number of pain signalling nerves and their sensitivity to strain and tension results in enhanced pain sensitivity, lower pain thresholds and the development of chronic pain states.

Chronic pain states, may be a result of prolonged stress and musculoskeletal tension, alongside central changes in the brain and spinal cord. So, if regular headaches are wearing you down you might benefit from trying to reducing your stress levels, being aware of dietary triggers, improving your posture and trying exercises to relax your muscles.

Post by: Isabelle Abbey-Vital

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Michael Schumacher’s traumatic brain injury explained

Schumi di GP Kanada 2011 cropped Michael Schumachers traumatic brain injury explained

Photo by Mark McArdle

Seven times Formula 1 World Champion and holder of a huge number of driving records, Michael Schumacher is thought of as the greatest F1 driver of all time, a champion among champions. On 29th December last year on a ski slope in the French Alps, Schumacher fell and hit his head on a jagged rock. Witness reports claim that he lost consciousness for about a minute, but that ten minutes later, when the emergency helicopter arrived, he was conscious and alert. Over the next two hours, however, Schumacher’s condition deteriorated and since that day, he has had two head operations and has remained in intensive care under a medically-induced coma.

Epidurales Haematom Michael Schumachers traumatic brain injury explained

An epidural haemotoma caused by a fracture in the skull (indicated by the arrow). Image by Hellerhoff.

Traumatic brain injury, or TBI, is quite a vague medical term and simply describes any injury to the brain sustained by a trauma – that is, a serious whack to the head. TBI is the most common brain disorder in young people: while older people are at higher risk from degenerative diseases, young people are more likely to find themselves in car crashes, fights or…ski accidents.

The specific type of TBI that Schumacher is believed to have suffered is an epidural haemotoma (click here for a seriously gory video of a haemotoma clot removal – you have been warned). Between the brain and the skull are a number of protective layers; these are membranes which encapsulate the brain and spinal cord, all of which swim around in cerebrospinal fluid. An epidural haemotoma is a bleed between the tough outermost membrane, called the dura mater, and the skull. Technically this sort of bleed isn’t in the brain itself, but this injury seriously affects the brain due to one important factor: pressure.

Brain herniation types 2 Michael Schumachers traumatic brain injury explained

Six ways a brain squeezed by a bleed can go. Coning (indicated by number 6) is a last resort but compresses respiratory centres and can be fatal. Image by Rupert Millard.

Since the skull is an almost totally enclosed space, a bleed that grows too big in size could end up pushing, not just on the inside of the skull, but on the brain itself – squeezing it into an ever-decreasing volume. When put under pressure the only way the brain can physically go is down towards the spinal cord, but if this happens, the brainstem at the base of the brain may become compressed. This horrible scenario, known as ‘coning’, has a really high fatality rate, as the brainstem is needed to keep our heart pumping and lungs breathing. So keeping intracranial (in-skull) pressure low after TBI is key.

Doctors have reported that, as well as a haemotoma, Schumacher suffered contusion and oedema. Cerebral contusion is essentially bruising, as you might expect in other parts of the body: tiny blood vessels bleed when they have suffered a serious hit – in this case either from the rock itself, or from the other side of Schumacher’s skull in a ‘rebound’ type impact. Oedema, or swelling, may come as a result of the contusion – like when a bruised knee swells – and again would need to be curbed in order to prevent the pressure inside the skull from rising dangerously.

 Michael Schumachers traumatic brain injury explained

Illustration by Max Andrews.

So what have the doctors done to treat Michael Schumacher’s condition? Well, firstly, the surgeon Prof. Stephan Chabardes has reportedly performed two operations to remove blood clots from the haemotoma, as well as a craniectomy – removal of part of the skull – in order to relieve the intracranial pressure and prevent coning. Craniectomy has been used for some time to treat both TBI and stroke, but remains somewhat controversial, mainly because of the risks of further bleeds, infections, or herniation of brain tissue through the surgically-made hole in the skull.

The second main strategy in treating Michael Schumacher has been to keep him under an artificial or medically-induced coma. This involves sedating him with strong anaesthetic agents. Propofol, which quietens brain activity by boosting inhibitory GABAA (‘off’) receptor activity and by blocking sodium (‘on’) ion channels in neurons, or barbiturates, which also enhance GABAA receptors, but block excitatory glutamate (‘on’) channels could be used to keep him sedated and to ‘slow’ his brain down. Slowing is achieved through a net reduction in excitatory activity within the brain. Thus, the medically-induced coma not only stops the patient being conscious, through what no doubt would be a painful experience, but also limits the amount of activity-related blood flow, curbs swelling and prevents what’s known as excitotoxicity.

Pts bar graph by severity Michael Schumachers traumatic brain injury explained

Risk of post-trauma seizures after TBI by the severity of the initial injury. Graph by Delldot (wiki).

Excitotoxicity can occur after TBI, stroke or in patients with epilepsy. It is a term used to describe what happens when brain cells run out of energy or become overloaded with excitatory inputs. In this state cells become overexcited and die, either immediately, or after a delay. Seizures, which can cause excitotoxic cell death, are fairly common after severe TBI and are thought to drive brain damage after the original injury. Seizures after TBI can be worsened by swelling and higher temperatures, so it is likely that Schumacher has been kept a few degrees cooler than his normal body temperature to limit this risk.

 Michael Schumachers traumatic brain injury explained

Data as interpreted from Laureys S, Owen AM, Schiff ND (2004). “Brain function in coma, vegetative state, and related disorders”. The Lancet Neurology 3 (9): 537–546. Graph by Shin Andy Chung.

If he is still in a medically-induced coma, or is gradually being weaned off the anaesthetic agents, Schumacher may be undergoing physical therapy to move his limbs and joints to prevent muscle wastage, or contracture, which is irreversible muscle shortening. If his condition improves and he is able to move, his limbs will need re-strengthening.

Some conflicting reports suggest that doctors treating Michael Schumacher may have started removing him from his coma. If they are doing this, the full extent of their patient’s rehabilitation needs won’t become clear for some time. While I obviously hope the driving legend makes a full and speedy recovery, it is hugely unlikely that his brain will completely recover all its previous functions. The brain is such a delicate organ and Schumacher’s tragic case only highlights its fragility.

 Michael Schumachers traumatic brain injury explained

Hugo Lloris in 2012. Photo by Stanislav Vedmid.

Schumacher’s injuries also raise the debate on the guidelines of treating head injuries in sports. Last November, Tottenham’s Hugo Lloris lost consciousness after a hit to his head during a football match, but after waking up was allowed to return to the pitch to finish the game. Lucid intervals, such as the one reported shortly after Schumacher’s fall, can be deceptive and players of contact sports should always be given immediate medical attention after losing consciousness. It’s no news that the cumulative effects on the brain of losing consciousness multiple times – as many boxers do on a regular basis – are to be avoided at all costs.

Every year in the USA, 1.7 million TBIs – more than double the number of heart attacks – contribute to almost a third of all accidental deaths as well as varying levels of lasting disability. While we hold our fingers crossed for Michael Schumacher’s successful rehabilitation, we must also think of the other thousands of people, and their families dealing with the long-term aftermath of serious brain injuries around the world.

 Post by Natasha Bray

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Playing at a better future: Could video games improve your life?

954632422 bdaace0ea6 m Playing at a better future: Could video games improve your life?Your brain is plastic. No, not like the picture to the right but in the sense that everything which makes us who we are (our thoughts, beliefs and understanding of the world around us) can be subject to change. This change may come from our interactions with the world, as we learn to adapt and live in a changing environment, or the change may come from within, as we make conscious decisions to view the world differently. This natural plasticity helped our ancestors adapt when their environments changed and undoubtedly played an important role in their continued survival. However, a recent media storm has grown around the way brains, especially teenage brains, may be altered in response to societies’ increasing use of technology. This interest has raised concerns surrounding the impact technology, such as social media and video games, could have on the growing brain.

5292485408 47104b91b6 199x300 Playing at a better future: Could video games improve your life?Video games in particular may be thought to bring together a ‘perfect storm’ of attributes primed to alter your brain. Specifically, they provide us with challenges that stretch our abilities but that are also matched to the our current gaming level; thus, are always achievable. This type of challenge makes us feel particularly good, since we feel as though we have earned our own rewards (such as in-game experience points or unlocking a new level of game play) through what we perceive to be hard work. Thus, we feel a sense of accomplishment and our brains are thought to undergo changes which reinforce certain game-related behaviours.

A number of scientific studies have explored the negative effects gaming can have on the developing brain. And, there have been a range of reactive articles exploring the notion of a dystopian future where a generation of emotionally blunted sociopathic adults cruise around heartlessly re-enacting crimes from games such as Grand Theft Auto. However, it is important to understand that many diverse activities lead to changes in brain structure and function and that these changes are not always negative. Indeed, some studies are now beginning to highlight the positive effects games have on development and how games may be designed to improve mental function.

2305701220 0fc3d01183 m Playing at a better future: Could video games improve your life?Interestingly, game developers and scientists are now coming together in the hope of tackling depression, a major cause of disability, especially amongst young adults (up to a quarter of young people will have experienced a depressive disorder by the age of 19). Sadly, shortages in trained councillors and the reluctance of some young people to seek traditional help means that fewer than a fifth of young people with depressive disorders will actually receive treatment.

A research group, lead by professor Sally Merry at the University of Auckland, have developed a role playing game (SPARX), based around the principles of cognitive behavioural therapy (CBT), which aims to help young people cope with depressive disorders. SPARX is an interactive first person role playing game which allows the user to design a playable character, who is then charged with restoring ‘balance’ to a fantasy world dominated by GNATs (Gloomy Negative Automatic Thoughts). The game leads the screen shot 2012 05 07 at 19.53.51.0 cinema 640.0 300x300 Playing at a better future: Could video games improve your life?player through a range of interactive levels where they learn different CBT techniques aimed at interrupting and readdressing negative thought patterns. At the beginning and end of each level the user interacts with a ‘guide’ who explains the purpose of the in-game activities, provides education, gauges the players mood and sets them real-life challenges (equivalent to homework). Players’ progress is monitored throughout and young people who are not seen to improve are prompted to seek further help from their referring clinicians (a trailer of SPARX is available at www.sparx.org.nz).

Studies suggest that SPARX significantly reduces depression, hopelessness and anxiety in young gamers and that the game is at least as good as traditional CBT. Game designers have also worked hard to make sure the game is engaging for young people; and this seems to have worked: 60% of players completed the whole game while 86% completed at least 4 levels and the majority of young people stated that they would recommend the game to their friends. This is a pretty impressive statistic, since teenage gamers are notoriously hard to please and a self help fantasy RPG certainly sounds like the kind of thing teens would dismiss as being ‘lame’. The success of this intervention suggests that such games could be a great way to treat patients who do not have access to therapy or who may be reluctant to engage with conventional therapeutic methods.

Ultimately the world of gaming is huge and only getting larger. It is currently estimated that by the age of 21 the average young gamer will have spent around 10,000 hours gaming; this is almost equivalent to the time they will have spent in school! With young adults investing so much of their free time in the gaming world, it’s about time we set about understanding the influence games have on development and perhaps, as SPARX has done, start putting these games to work for us. Just think, if we could harness the pleasure gamers feel when working towards gaming-related goals, we could use this medium not only to educate but perhaps also to encourage people to ‘play’ at the biggest puzzle game around – scientific research. The future seems full of amazing possibilities, so put your game face on and join the fun!

Post by: Sarah Fox

 

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First patients enrolled on study aimed to improve outcome following brain injury.

Formed from around 80-90 billion neurons and with a consistency so soft you could cut

trauma 150x150 First patients enrolled on study aimed to improve outcome following brain injury.

A head CT image taken years after a traumatic brain injury, showing an empty space marked by the arrow were the damage occurred.

it with a table knife, the brain is a delicate vulnerable organ. Unfortunately, despite its hard outer shell (the skull), the brain is still susceptible to many forms of damage, both external and internal. Two common forms of brain damage are subarachnoid haemorrhage (SAH – a type of stroke caused by bleeding in and around the brain) and traumatic brain injury (TBI – occurring when an external force causes injury to the brain, i.e. hitting your head). It is not always possible to prevent this type of injury, however, scientists from Edge Therapeutics, Inc are currently working hard to develop life-saving hospital products capable of improving the outcome of patients following SAH and TBI.

Edge Therapeutics are currently enrolling patients on Phase I/II clinical trials for their pipeline drug EG-1962. Despite its inaccessible name, EG-1962 is designed to perform a unique and possibly life-saving function. The drug is designed to treat a state known as delayed cerebral ischemia (DCI). DCI is a complication and major cause of death and disability which occurs in patients within the first two weeks following brain injury. As the name suggests, DCI causes cellular damage through ischaemia (restriction of blood flow to the tissue). This ischaemia can result from a number of mechanisms stemming from the site of brain injury, including cerebral vasospasm (a narrowing of vessels carrying blood), cortical spreading ischaemia (decreased blood flow caused by mass activation of large populations of brain cells) and microthrombembolism (a blockage of blood flow around small, trauma-induced blood clots).

blood 150x150 First patients enrolled on study aimed to improve outcome following brain injury.

Cerebral angiogram showing the blood vessels in a brain.

EG-1962, also referred to as nimodipine microparticles, is a novel preparation of the FDA-approved drug nimodipine. This preparation encapsulates nimodipine in a biodegradable coating which can be injected directly at the site of injury, releasing nimodipine steadily over a period of 21 days. This new system is thought to be an improvement on the current method of oral delivery, which is more likely to cause nasty side effects (such as low blood pressure and lung complications) and less likely to supply sufficient drug to areas where it is needed.

E. Francois Aldrich, M.D. (an Associate Professor of Neurosurgery at the University of Maryland and the Chief of Cerebrovascular Surgery) stated that he hopes the study will help select on optimal dose of EG-1962, which could potentially prevent DCI, therefore improving the lives of a number of patients suffering from various forms of brain injury.

The current study, dubbed NEWTON (Nimodipine microparticles to Enhance recovery While reducing TOxicity after subarachNoid hemorrhage), will enrol up to 96 patients in approximately 20 centres internationally. This study aims to ensure EG-1962 is safe; to discover the most safely effective dose; and to assess whether EG-1962 offers a significant improvement over oral nimodipine. Results are expected in the first half of this year and Dr. R. Loch Macdonald, Chief Scientific Officer at Edge Therapeutics, hopes that these findings will lead to further advances in the clinical development of the drug.

Although a significant number of drugs undergoing Phase I/II trials will fail to progress any further, it is hoped that this treatment or similar preparations may soon be available to reduce the damage caused by DCI.

Post by: Sarah Fox

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Science in 2014: What will the future hold?

The new year is usually reserved for looking back and reflecting over what has just gone. But it’s also a good time to look forward into the upcoming year and think about what it may bring.

Science is no exception to this. 2013 has been a remarkable year; we had our first taste of lab-grown meat, the Curiosity Rover found water on Mars and Richard III turned up in a car park. But what will 2014 bring to the world of science?

The Rosetta Spacecraft will hopefully tell us more about comets and the origins of the universe

comet Science in 2014: What will the future hold?

The Rosetta Spacecraft was launched in 2004 and has been on a 10 year journey towards the comet 67P/Churyumov-Gerasimenko. The spacecraft, which has been in a state of hibernation since July 2011, will wake up on January 20th 2014. It is hoped that Rosetta will begin mapping the comet in August and eventually land a probe on its surface in November, then Rosetta will travel with the comet towards the Sun until December 2015. It is hoped that the information gathered from Rosetta will help to better understand the role comets play in the origins of the universe.

Better diagnostic techniques for cancer

syringe 150x150 Science in 2014: What will the future hold?

Last year, laboratory supply giants Qiagen teamed up with the company Exosome Diagnostics to develop a less invasive test for cancer and other diseases, which may one day replace standard tissue biopsies. This technology makes use of tiny spheres of fat called exosomes. Exosomes are formed inside cells, before being released into the body where they travel in fluids such as spinal fluid, urine and blood. The inside of these exosomes can contain many bits of information about the cells they were released from, including genetic material such as RNA and DNA. It is hoped that 2014 will see the implementation of technologies which harvest exosomes from body fluid and use the information they contain for early diagnosis and development of new treatment strategies.

Increased research into three-parent embryos

embryo 300x214 Science in 2014: What will the future hold?

Last year, I reported that the Human Fertilisation and Embryology Authority (HFEA) ethics committee were debating whether to allow research into three parent embryos in the UK. The committee found that there was widespread support for the technique and so approved the proposal. This means that the UK is the first country to approve the use of an IVF technique using the DNA from a mother, father and mitochondrial donor. Parliament are now producing draft regulations and the legislation should hopefully be put into place by the end of this year. This means that 2014 could be the start of a journey which may ultimately lead to the eradication of certain inherited diseases from family lines.

Laboratory-grown organs becoming closer to reality

petri dishes 214x300 Science in 2014: What will the future hold?

The last few years have seen a big increase in the number of organs successfully grown in the lab and this technology is now providing real benefits for patients as lab-grown organs, including windpipes and bladders, are being used as transplants.

The ability to grow complex organs, such as a liver or pancreas, would be a huge leap forward which could revolutionise transplantation techniques and help cure diseases such as diabetes. In 2013 it was reported that scientists were able to produce tiny livers and mini brains outside of the body. This amazing technology may one day provide the answer to our shortage of transplant donors, while lab-grown organs derived from a patient’s own stem cells may also eliminate the problem of transplant rejection. Although, it is unlikely the coming year will see the development of fully functioning complex lab-grown organs, these techniques have come forward in leaps and bounds and, hopefully, 2014 will bring us another step closer to growing complex organs outside the body.

Of course, this is just the tip of the iceberg. One of the most exciting things about science is that it isn’t always clear what the future holds. We have very little idea really what will be discovered in 2014; I’m looking forward to watching the stories unfold and the discoveries roll in.

Post by: Louise Walker

What do you think 2014 will hold for scientific discovery? Please let us know in the comments below

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Flashes of brilliance in the brain – the best neuroscience images of 2013

Pretty pictures and popular neuroscience go hand-in-hand. People love to see the contours of their brain on an MRI and journalists are drawn to a brain flashing away with activity. There have been some fantastic images from neuroscience in 2013. Here are my favourites, one for each month starting way back in January 2013.

Disclaimer – We own no rights to any of the images on this page. All images are credited to the original authors and copyright holders. The MRC’s Biomedical Picture of the Day has been used as inspiration for some of the images.

January – New eyes for blindness

Blindness is a major challenge to the neuroscience field. Untreatable blindness is often caused by a degeneration of the light-sensitive cells of the retina. Here, researchers from University College London, UK have injected new photoreceptor cells into the retina of mice with retinal degeneration restoring normal responses to light!

Retina Repair transplant Flashes of brilliance in the brain – the best neuroscience images of 2013

Host retina cells are shown in blue, injected new photoreceptive cells are shown in green. The top left is a healthy mouse. The next three images show three different types of genetic blindness models in mice – all show integration of the injected cells. From Barber et al. PNAS 110(1): 354-359

February – Pathfinding connections in the brain

This year there has been a burst of activity in the ‘connectomics’ field. Mapping the connections of the brain is the next big challenge of neuroscience and the main topic of the Human Brain Project in Europe and the BRAIN initiative in the US.

Here, researchers from the École Normale Supérieure in Paris, France looked at how neurons find their way from the thalamus in the middle of the brain to the outermost folds of the cortex. 

Pathfinding Flashes of brilliance in the brain – the best neuroscience images of 2013

These figures show neurons in green making their way from the thalamus (Th) to the cortex (NCx). From: Deck et al. Neuron 77: 472-484.

 

March – Whole brain activity

Seemingly a burning campfire, this is actually a brain flashing with activity. In one of the most impressive images of neuroscience in 2013, researchers from Howard Hughes Medical Institute’s Janelia Farm campus in the US used calcium imaging (see July) to view the activity of a whole brain.

Zebrafish Flashes of brilliance in the brain – the best neuroscience images of 2013

The brain of a zebrafish larvae – imaged by light-sheet microscopy. From Ahrens et al. Nature Methods 10: 413-420.

One of the biggest challenges of neuroscience is working out how everything links up together. The most accurate measurements we currently have can only take into account a handful of cells at once. The brilliance of this technique, utilising see-through zebrafish larvae, is that they were able to image more than 80% of the neurons of the brain at once. This can tell you how large populations of cells interact, allowing different regions to work together.

For more info see this article by Mo Costandi in the Guardian.

 

April – See-through brains

Another amazing technical feat designed to view how the brain links together, in April we were brought CLARITY. By dissolving the opaque fat of a brain whilst keeping the structure intact, researchers led by Karl Deisseroth at Stanford University, California were able to image a whole mouse brain.

CLARITY Flashes of brilliance in the brain – the best neuroscience images of 2013

The hippocampus of a mouse, visualised with CLARITY. Excitatory cells are green, inhibitory cells are red, and support cells called astrocytes are blue. From Chung et al. Nature 497: 332-337.

The images from this technique are truly breath-taking. Using this technology, researchers could look in detail at the structure of the brain, giving valuable information of the wiring of different regions. They even imaged part of a post-mortem human brain from an autistic patient, finding evidence of structural defects normally associated with Down’s syndrome.

For more info, see this article in New Scientist.

 

May – Brainbow 3.0

‘Brainbow’ is a transgenic system designed to label different types of cells in many different colours. Prime material for pretty pictures. Take a look at these:

Brainbow Flashes of brilliance in the brain – the best neuroscience images of 2013

Multicoloured neurons. b shows the hippocampus, c and d show the cortex. From: Cai et al. Nature Methods 10: 540-547.

 

June – Controlling a helicopter with your mind

In June, researchers from the University of Minnesota, USA showed that one could fly a helicopter with their mind! Watch below as the subject guides a helicopter using an EEG skullcap.

July – Better calcium sensors

More calcium imaging now. Calcium imaging works by engineering chemicals that will fluoresce when they encounter calcium. When nerve cells are active, millions of calcium ions flow into the cell at once, therefore a flash of fluorescent light can be seen. Here, researchers from Howard Hughes Medical Institute’s Janelia Farm campus in the US have been working on better, more sensitive calcium sensors. Using these you can colour code neurons based on what they respond to.

Calcium sensor Flashes of brilliance in the brain – the best neuroscience images of 2013

Neurons colour-coded by their response properties. From Chen et al. Nature 499: 295-300.

They were also able to record a video of the electrical activity in dendritic spines, the tiny arborisations of nerve cells – see here.

 

August – Using electron microscopy to connect the brain

Drosophila are wonderful little flies with nervous systems simple enough to get your head around, but complicated enough to be applicable to our own.

Drosophila EM Flashes of brilliance in the brain – the best neuroscience images of 2013

An electron micrograph, colour coded for each individual neuron. From: Takemura et al. Nature 500: 175-181.

Here, researchers from Janelia Farm (again!) have performed electron microscopy on drosophila brains to connect up neurons across multiple sections. An algorithm colour codes them to line up the same neuron in different sections in what looks like a work by Picasso.

 

September – Astrocytes to the rescue

Astrocytes are support cells in the brain which become highly active following brain injury. Here, researchers from Instituto Cajal, CSIC in Madrid, Spain were interested in the different characteristics astrocytes take on when a brain is injured. The injury site can be seen as a dark sphere. Astrocytes with different characteristics have been stained in different colours. For example, the turquoise-coloured astrocytes can be seen forming a protective net around the injury site.

Astrocyte Flashes of brilliance in the brain – the best neuroscience images of 2013

The injury site (dark sphere) can be seen surrounded by multi-coloured astrocytes. From: Martín-López et al. PLoS ONE 8(9) .

 

October – Preserved human skulls

Not strictly neuroscience but these images need to be included. Published in October 2013, The New Cruelty (commissioned by True Entertainment), photographed a series of preserved human skulls.

NewCruelty Flashes of brilliance in the brain – the best neuroscience images of 2013

A preserved human skull. From the New Cruelty exhibition, commissioned by True Entertainment.

 

November – Brain Computing

Part of the vision of the Human Brain Project and the BRAIN initiative is to marry anatomy of the brain with computer models to try to produce a working computer model of the brain. This image represents BrainCAT, a software designed to integrate information from different types of brain scan to gain added information about the functionality of the brain.

BrainCAT Flashes of brilliance in the brain – the best neuroscience images of 2013

This image shows BrainCAT linking functional MRI data (blue and turquoise shapes) with connectivity data (diffusion tensor imaging – green lines). From: Marques et al. Front. Hum. Neurosci. 7: 794.

 

December – Men Are from Mars, Women Are from Venus.

The last month of the year gave us preposterous headlines of ‘proof’ that “Men and women’s brains are ‘wired differently’”. This finally proved why women are from Venus and men are from Mars; why men ‘are better at map reading’ and women are more ‘emotionally intelligent’…. These exaggerated headlines have been kept in check recently on this blog but there’s no denying that the research paper did show some lovely images of male and female brain connections.

MaleFemaleConnections Flashes of brilliance in the brain – the best neuroscience images of 2013

The top shows the most interconnected male regions, the bottom shows the most interconnected female regions. From: Ingalhalikar et al. PNAS (online publication before print).

So that’s it. 2013 was a year of flashing brains, dodgy connections and overegged hype. Let’s hope there’s even more to come in 2014.

Post by Oliver Freeman @ojfreeman

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Battle of the brain’s sex differences…or not really?

Why some people are surprised at the very idea of there being differences between male and female brains I don’t understand. But, what really confuses me is when journalists misinterpret research findings and overextrapolate speculative comments to fit cliched gender stereotypes.

65464 web 300x225 Battle of the brains sex differences...or not really?

“Brain networks show increased connectivity from front to back and within one hemisphere in males (upper) and left to right in females (lower).”
Credit: Ragini Verma, Ph.D., Proceedings of National Academy of Sciences, from press release.

Whenever I ask my (less sciencey) friends what they’d like to read on The Brain Bank, there is a perennially raised topic. At least one, usually single, hopeful will ask desperately for a guide on how men and women’s brains differ – and why they might work in different ways, scientifically speaking. Efforts to crack the mental codes of the opposite sex started as far back as Aristotle, who claimed that women were “more mischievous,  … more easily moved to tears[,] more apt to scold and to strike[,] … more void of shame or self-respect,…of more retentive memory” (History of Animals).

 Battle of the brains sex differences...or not really?

White matter tracts, as imaged using diffusion tensor imaging. Author: Xavier Gigandet et al., source here.

Earlier this month, a research paper from the University of Pennsylvania used a fancy imaging technique called diffusion tensor imaging (DTI) to solve the mystery behind the different ways guys and gals think. DTI basically gives you a picture of where the white matter tracts – the wiring between different brain areas – lie between various processing parts of the brain.

The technique works by looking at how water travels within the brain: water ‘prefers’ moving along bundles of fibres, such as white matter tracts. In this way, DTI examines the strength of ‘connectivity’ between various parts of the brain.

Researchers, led by Prof Ragini Verma, scanned the brains of 949 youths aged 8-22. They found that, in general, the connecting pathways within each half of the brain were stronger in guys, but that in girls, the wiring between the two halves was stronger. In other words, connectivity in girls tended to be more ‘left-right’, whereas in boys, ‘front-back’ connectivity was stronger.

The researchers also reported that the girls performed better on tests involving attention; word and face memory; and social cognition, whereas boys fared better on spatial processing and sensorimotor speed tasks.

 Battle of the brains sex differences...or not really?

NOT REALLY. Author: Miz Mura.

This paper and its associated press release rallied some…OK, a lot, of interest from the press. But then something strange happened. Something was lost in translation between the original paper and the resulting newspapers reports, claiming that ‘hardwired’ differences between men and women’s brains might explain ‘why men are better at map reading’ and women are more ‘emotionally intelligent’…

OH dear…

 Battle of the brains sex differences...or not really?

Seriously, NOT REALLY. Author: Miz Mura

…Then there was a knee-jerk reaction against the potentially neurosexist connotations of this ‘kind of science’, and not just because the research was published in PNAS (hehe). In my opinion, if a conclusion is based on valid and reliable science, you shouldn’t really argue unless you have definitely read the research. If, on the other hand, the offending ‘conclusions’ are the result of a bizarre ‘Chinese Whispers’ scenario where no one has actually read the original research, then no,  it’s probably not worth listening – but then, mistranslation isn’t based on science anyway…I digress.

While we all know that there are some obvious – and other more subtle – distinctions between men and women. This research article doesn’t actually claim to explain anything besides the physical connections between different parts of the brain. Just to clarify, here are some of the problems with treating this particular research paper as the Holy Grail of sex differences:-

1. There’s no saying whether there’s a big difference or not. The authors present (undeniably) a very striking diagram, with the statistically significant bits indicated in gender-relevant colours. However, just because a difference is statistically significant, doesn’t mean the effect of being male, or female is a big deal. In fact, as the study uses such a large sample (949 youths), even very small differences between male and female brains may prove significant.

2. Less wiring doesn’t necessarily mean lower ability. The authors don’t actually indicate anywhere in the paper that the ‘wiring’ is associated with men and women’s differing abilities on the tests – though Prof Verma has been quoted speculating on the possibility. Instead, the authors have pointed out the brain’s physical differences and then separately comment on behavioural differences without saying whether the two correlate.

If the hypothesis is that men or women with mega-strong connectivity left-to-right, or front-back are respectively better at, say, language, or football, you could easily find that out with a bunch of correlations. Not that correlation would imply causation anyway. In fact, the strengthening or weakening of physical connections could even suggest that women and men’s brains change to compensate for innate differences!

3. Size/proportions might matter. It’s pretty well-known that men have larger brains than women – the situation is pretty complicated though, as women reportedly have more grey matter, less white matter and a thicker cortex than men. However – please correct me if I’m wrong – the authors don’t correct for brain sizes (either front-back, left-right, total volume or any other measure), which could be very important. Especially considering the people being imaged are aged between 8 and 22, when brains grow a lot anyway. Not to mention that girls and boys grow at different rates too. Oh well.

 Battle of the brains sex differences...or not really?

Social media word clouds for females (top) and males (bottom). Size = strength of the correlation; color = relative frequency of usage. Underscores (_) connect words in phrases. Words and phrases in center; topics surround. Author: H. Andrew Schwartz et al.; Source. Apologies for the bad language!

4. There are many more potential mechanisms than meets the eye. Yes, it’s very possible that exposure to sex hormones could change the brain’s connectivity. But, there’s a whole host of other possible influences on a child going through puberty that can’t be ruled out, because the brain is notoriously/amazingly plastic. Environmental influences, influences that can’t ever be controlled for, such as parents, peers, teachers and the media – could just as easily alter the physical structures of the brain, or the brain’s abilities. In fact, hearing in the news that ‘men are better at map reading’ because it’s ‘hardwired’ in their brains is conceivably rather likely to make guys feel a bit more confident navigating, while discouraging women from taking that responsibility instead.

This piece of research is not the first and certainly won’t be the last to be accidentally misinterpreted or overhyped. Research into the differences between men and women will continue to fascinate us because, for whatever reasons – social, biological or otherwise – people of different sexes tend to look, sound and act differently. More seriously (and the authors of the paper explain the motivation of their research), sex differences are linked to brain disorders like autism and depression, so the differences between ‘Martians’ and ‘Venetians’ should be properly understood, and carefully reported.

For further examination of this topic, here’s another blog article and a BuzzFeed piece with a few more reasons why it should all be taken with a pinch of salt.

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