alsbrainblog

[alsbrainblog]

The Neuroscience of Happiness

What is happiness and how can we boost it?

It’s easy to think of happiness as just a positive emotion that involves feeling ‘good’ and content. However, a happy person doesn’t walk around feeling like this 24/7; they still experience life’s ups and downs - they just deal with them better and foster an overall positive lifestyle.

The World Happiness Report 2015 (1) has a chapter on the ‘Neuroscience of Happiness’, written by R. Davidson and B. Schuyler, that emphasises four aspects of well-being, noting how they each play an important role in the notion of happiness. These consist of 1. Sustained positive emotion, 2. Recovery from negative emotion, 3. Empathy, altruism and pro-social behaviour, and 4. Mindwandering and mindfulness. I’m going to talk through each of these briefly.

1. Sustained positive emotion

The ventral striatum is a nucleus of neurons within the brain, and has been showed to activate when we think ‘happy thoughts’ such as winning the lottery, or when we see a photo of our child. Examining both healthy control subjects and depressed patients, Heller et al. (2) found that positive images caused the ventral striatum in both groups to activate to a similar degree. However, when this activation was measured over a longer period of time, differences between the groups began to appear. Specifically, healthy subjects showed sustained nucleus activation as the experiment progressed whereas depressed patients did not.

As a follow-up, they then found that antidepressant treatment went hand-in-hand with both sustained ventral striatum activation and an increase in reports of positive feelings in depressed patients (3). Prettyyy cool.

It was also found that people with greater sustained activation of the ventral striatum (and the dorsolateral prefrontal region) had lower levels of the body’s stress hormone, cortisol, suggesting less activation of stress responses (4). It seems to be that measuring the sustained activity of these brain areas can predict our psychological well-being and cortisol levels to an impressive degree.

So, sustaining the happy feeling is our first important factor. Next up...

2. Recovery from negative emotion

AKA resilience, AKA “the maintenance of high levels of well-being in the face of adversity”.

One way of measuring emotional recovery is observing the brain’s activation following the presentation of a negative emotional stimulus. The logic here is that slow, prolonged activity reflects a “continuation of the emotional response when it ceases to be relevant” (1)- therefore, fast recovery following a negative stimulus should reflect better well-being.

The happiness report considers the brain’s amygdala a central node for resilience due to the piles of evidence implicating its role in fear and anxiety. Therefore monitoring amygdala activity is sensible for assessing resilience.

Participants viewed emotional images, and then were sometimes subjected to loud bursts of sound - the level of ‘startle’ they exhibited was used as a measure of sustained emotional arousal. Remove the negative image and the ‘startle’ diminishes faster for some people than others. Those people who recover better (faster) following negative events show higher scores on the Purpose in Life subscale. (5)

The report even suggests that opportunities that provide moderate levels of adversity may help us learn emotional regulatory strategies to help us recover from the really bad events that knock us down. So, y’know, maybe there’s another reason to stand up for yourself if someone cuts in front of you in a queue... you’re training your brain to be more resilient. 

3. Empathy, altruism, and pro-social behaviour

What about our social relationships? It’s well known that happy people have fulfilling, supportive social connections. Social isolation has shown to activate the physical pain regions of the brain (6), buying gifts for people feels good, and pro-social behaviour can activate feedback loops of increased wellbeing and even more pro-social behaviour and so on.(7)

Empathy has shown to manifest itself in the emotional centres of the brain, seeing someone hurt often makes you experience similar feelings in similar brain areas (8). Research has shown that if you feel more connected to someone (even if they just support the same team as you) you’re empathetic reaction to their experiences is stronger. (9)

Our good friend, the ventral striatum (a ‘happiness’ centre for the brain), activates when we receive money and  when we donate it to charity. In fact, evidence shows that it is even more active when giving than receiving! It make sense that those who find giving to charity intrinsically rewarding (via the ventral striatum) are more likely to engage in donating. (10)

Our other good friend, the amygdala (fear and emotion centre), has shown to have both increased volume and bigger response to faces of people in fear (i.e. representing sensitivity to the suffering of others) in individuals who are classed as “extraordinary altruists” and might, say, donate a kidney to a stranger. (11)

If we can train ourselves to be to show more empathy (sharing the feelings of others), compassion (concern and desire to help others), and recognise/be mindful of our own emotions, the evidence suggests that, not only do we get better at understanding people’s feelings, but we also become happier people ourselves.

Going back to our favourite wordy brain regions, the ventral striatum and dorsolateral prefrontal cortex, research has shown that stronger increases in connectivity between these two brain areas predicts more helping behaviour. All about training that brain!

4. Mindwandering and mindfulness

Using a smartphone app, Killingsworth & Gilbert (12) sampled more than 2000 people to see how often their minds ‘wandered’ from the activities they were engaged in and how happy/unhappy they were in that moment. They found that, in general, people were less happy when their minds wander from the task at hand. In fact, one experiment showed that some college students would rather suffer electric shocks than sit in a room alone for 6-15 minutes. Imagine that, some of us hate being left to our own thoughts so much, we’d rather be electrocuted... is our own company really that unpleasant? (13)

In the absence of a task, our brain’s ‘default mode network’ becomes active, coinciding with the feeling of mindwandering (14). We can counter the negative feelings that this brings using mindfulness - a technique that’s all the rage on meditation apps.

Alright, bear with me as I explain this vague concept: mindfulness involves looking inward and simply paying attention to your body and mind in a non-judgemental way. Just observing, reflecting, and breathing. People often focus on their breathing, and just have a moment to themselves without the noisy buzz of the outside of the world distracting them. Some people do it by staring at a single small object and focusing on its features, or taking note of the different background sounds they can hear. It’s a refreshing task, just taking a pause from life, detaching oneself, and has shown to decrease activity in the ‘default mode’ regions and improve well-being. Furthermore, counting our breaths (a form of mindfulness) has shown to reduce our level of distraction from stimuli in experimental research. (15)

Summary

That was a lot, I realise, but according to The World Happiness Report these are the big four constituents of happiness and well-being. Individuals who can better sustain positive feelings, ‘bounce back’ from negative experiences, engage in altruism and empathy (nobody regrets taking part in community-driven projects and charitable actions!), and improve their mindfulness show elevated well-being.

Remember that you can train these skills, and subsequently the brain regions and connections that they relate to, to become a healthier, happier individual! However, I’ve written this whole blog post and even I struggle to practice mindfulness and could definitely carry out more altruistic actions - but remember self-improvement and the pursuit of happiness is a gradual process that we work towards step by step.

Stay happy, my friends.

Al 

(1) Davidson, R. J., & Schuyler, B. S. (2015). Neuroscience of happiness. World happiness report, 88-105.

(2) Heller, A. S., Johnstone, T., Shackman, A. J., Light, S. N., Peterson, M. J., Kolden, G. G., … Davidson, R. J. (2009). Reduced capacity to sustain positive emotion in major depression reflects diminished maintenance of fronto-striatal brain activation. Proceedings of the National Academy of Sciences, 106(52), 22445–50. doi:10.1073/pnas.0910651106

(3) Heller, A. S., van Reekum, C. M., Schaefer, S. M., Lapate, R. C., Radler, B. T., Ryff, C. D., & Davidson, R. J. (2013). Sustained ventral striatal activity predicts eudaimonic well-being and cortisol output. Psychological Science, 24(11), 2191–2200.

(4) Heller, A. S., Johnstone, T., Light, S. N., Peterson, M. J., Kolden, G. G., Kalin, N. H., & Davidson, R. J. (2013). Relationships between changes in sustained fronto-striatal connectivity and positive affect in major depression resulting from antidepressant treatment. American Journal of Psychiatry, 170(2), 197–206. doi:10.1176/appi.ajp.2012.12010014

(5) Schaefer, S. M., Morozink Boylan, J., van Reekum, C. M., Lapate, R. C., Norris, C. J., Ryff, C. D., & Davidson, R. J. (2013). Purpose in life predicts better emotional recovery from negative stimuli. PloS One, 8(11), e80329. doi:10.1371/journal. pone.0080329

(6) Eisenberger, N. I. (2012). The pain of social disconnection: Examining the shared neural underpinnings of physical and social pain. Nature Reviews Neuroscience, 13(6), 421–34. doi:10.1038/nrn3231

(7) Aknin, L. B., Dunn, E. W., & Norton, M. I. (2011). Happiness runs in a circular motion: Evidence for a positive feedback loop between prosocial spending and happiness. Journal of Happiness Studies, 13(2), 347–355. doi:10.1007/s10902-011- 9267-5

(8) Lamm, C., Decety, J., & Singer, T. (2011). Meta-analytic evidence for common and distinct neural networks associated with directly experienced pain and empathy for pain. NeuroImage, 54(3), 2492–502. doi:10.1016/j.neuroimage.2010.10.014

(9) Hein, G., Silani, G., Preuschoff, K., Batson, C. D., & Singer, T. (2010). Neural responses to ingroup and outgroup members’ suffering predict individual differences in costly helping. Neuron, 68(1), 149–60. doi:10.1016/j.neuron.2010.09.003

(10) Moll, J., Krueger, F., Zahn, R., Pardini, M., de Oliveira-Souza, R., & Grafman, J. (2006). Human fronto-mesolimbic networks guide decisions about charitable donation. Proceedings of the National Academy of Sciences, 103(42), 15623–8. doi:10.1073/pnas.0604475103

(11) Marsh, A., Stoycos, S. A., Brethel-Haurwitz, K. M., Robinson, P., VanMeter, J. W., & Cardinale, E. M. (2014). Neural and cognitive characteristics of extraordinary altruists. Proceedings of the National Academy of Sciences. doi:10.1073/ pnas.1408440111

(12) Killingsworth, M. A., & Gilbert, D. T. (2010). A wandering mind is an unhappy mind. Science, 330(6006), 932. doi:10.1126/science.1192439

(13) Wilson, T. D., Reinhard, D., Westgate, E. C., Gilbert, D. T., Ellerbeck, N., Hahn, C., … Shaked, A. (2014). Just think: The challenges of the disengaged mind. Science, 345(6192), 75–7. doi:10.1126/science.1250830

(14) Callard, F., Smallwood, J., Golchert, J., & Margulies, D. S. (2013). The era of the wandering mind? Twenty-first century research on self-generated mental activity. Frontiers in Psychology, 4(December), 891. doi:10.3389/fpsyg.2013.00891

(15) Anderson, B. A., Laurent, P. A., & Yantis, S. (2011). Value-driven attentional capture. Proceedings of the National Academy of Sciences, 108(25), 10367–71. doi:10.1073/pnas.1104047108

[alsbrainblog]

Dementia

For this blog post I’m going to talk about one of the most difficult topics in neuroscience: dementia. Characterised mainly by long-term degradation in memory and cognition, dementia is exhibited by approximately 50 million people worldwide and this number will continue to grow as more people live longer lives.

There are many types of dementia, including alcohol-induced persisting dementia, dementia due to head trauma or HIV, Parkinson’s disease, and Huntington’s disease. However, the most common type is Alzheimer’s – which makes up more than half of all cases. 

First diagnosed in 1906, this form of dementia is named after Alois Alzheimer who described a patient in her fifties suffering from an unknown mental illness. Upon her death, an autopsy revealed dense deposits outside the nerve cells of her brain (known as neuritic plaques), and twisted strands of fibre (known as neurofibrillary tangles) inside these cells. As you may guess, these signs of Alzheimer’s are difficult to measure in a living person, and so a definitive diagnosis of the disease is still only possible post-autopsy. While the patient is alive, the only way to assume Alzheimer’s is to rule out the more easily-diagnosable forms of dementia (a method that is surprisingly effective, leading to correct diagnoses more than 90% of the time).

Those suffering from Alzheimer’s will usually progress from memory issues such as forgetting a person’s name or the placement of a familiar object, to disorientation in familiar places, forgetting conversations they recently had, to the most heartbreaking symptoms such as delusional beliefs and forgetting family members. I can remember my own grandma reaching this stage and it’s incredibly difficult for a family to witness.

Another form of dementia I want to talk about is vascular dementia – that which is caused by problems with the blood supply to the brain. A vast network of small blood vessels supply energy to and remove waste from the brain and so, if a stroke (i.e. blockage or bleeding out) were to prevent these vital processes from occurring, it follows that the brain will suffer. The symptoms of this type of dementia are very similar to other dementias, mainly including cognitive decline and memory impairment that are severe enough to interfere with daily life. The usual suspects are the major risk factors here: including high blood pressure, high cholesterol, smoking and old age. So, y’know, try and live healthy lives to maintain a healthy brain.

So what progress is being made? Well, we can inform people how to live lives that reduce the risk of dementia; work is being carried out to find dementia symptoms sooner, so treatment and care can be proactive rather than reactive; and promising therapies are always being discovered to help combat it. State-of-the-art technology (such as magnetic resonance imaging, or MRI, scanners) will better allow us to scan a living person’s brain to find signs of reduced blood flow or shrinkage of relevant brain regions. Useful drugs, such as acetylcholinesterase inhibitors, can be used to reduce the degradation of memory and cognition in Alzheimer’s patients; however, these drugs can’t stop the progression of disease, and that is why it is so important that we find a more effective cure soon.

It’s a tough area to talk about, because it feels like we are fighting an uphill battle against all these diseases that seem to want to strip us of our memories, personalities, and dignity towards the end of our lives. However, be reassured that a whole lot of funding is being poured into curing dementia, and that this research is being carried out by some of the brightest minds we have to offer.

Thanks for reading,

Al

[alsbrainblog]

Music on the Brain

I’ve written about sex and written about drugs, so now I think it’s time to look into rock and roll. 

Music is basically just patterns of vibrations that pass from the source to the air to your ears to your brain. The inner parts of your ears contain clever machinery to make sure the vibrations in the air are communicated to your brain accurately: the eardrum vibrates, causing the tiny bones within to vibrate at the same frequency, amplifying the pattern so that the tiny, pitch-specific hairs along the spiral-shaped cochlear are tickled such that the auditory nerve passes on the correct information to the brain. Viola! You can hear sounds, voices and music.

Sound

Ok, so if we’re listening to a song with lyrics, then it makes sense that the language areas of our brain become active. Wernicke’s area, heavily linked to the understanding of spoken and written language, and Broca’s area, associated with speech production and comprehension, will both ‘switch on’. Primarily, Wernicke’s to understand the lyrics and Broca’s to sing along with them.

Vision

Music stimulates the visual cortex, also. Closing your eyes and listening to music will very likely conjure up images and/or colours in your mind. Research has shown that it doesn’t matter what your background or culture is, we all associate bright colours with ‘happy’ music and dark colours with ‘sad’ music.

Body

Our favourite (or soon to be favourite) songs can trigger all the signs of emotional arousal in our bodies: dilated pupils, increase in blood pressure and heart rate, even blood is redirected to the muscles in our legs (possibly explaining toe-tapping to good tunes). Music seems to arouse our most basic biological wiring – just like food and sex. Neurons in your motor cortex can be triggered by music, leading people to get down and boogie. The cerebellum, a part of our brains heavily associated with movement, becomes active also in trying to guess what the music will do next.

Pleasure and prediction

A team of researchers in Montreal discovered that music triggers the release of dopamine in the pleasure-associated areas of the brain. This appears to be the same sense of bliss we feel from sex and drugs such as cocaine – all three provide a sense of happiness by activating these cells. More surprisingly, they found that our brains try to predict the arrival of our favourite part(s) of a song.

 Why are our brains (or more specifically, these dopamine neurons) so interested in the part of the song before we get chills down our spine? Perhaps it is because we crave unpredictability – we don’t get as excited when we know what’s coming. Do you know the main theme from the Fellowship of the Ring? That really great bit of music that plays when the Fellowship is finally complete, or something awesome is occurring? Well that is played sparingly in the films, to keep us wanting more. If it was played constantly we’d get a bit ‘meh’.

Musicians are known for making our brains beg for the chords that we love best, saving them for the big climax. Our brains try to predict the song, but don’t always succeed; this keeps us listening, waiting for the pattern to be completed and thus gain our ‘reward’.

If we hear a song too many times in a short space of time, it stops having the same effect on us. Music can be an addiction, similar to drugs (although much less destructive), as they both trigger the brain’s reward system. The ‘high’ isn’t as great if the song is listened to over and over, so we move onto another song to feed our hunger for variety and unpredictability.

Memory

I don’t mean to name-drop here, but it’s going to happen anyway. Me and my friend drove a campervan through Yosemite National Park a few years ago, and we were listening to “England” by the National as we drove (great song, you should check it out). Now, every time I hear that song I remember looking out of the windows at the trees rising way up above us, the mountains, lakes and blue sky, and it makes me very bloody happy. Music can tap into our brain’s memory systems to associate itself as part of our stored memories. Due to the interconnectivity of the brain, if you hear a certain song it can then trigger memories associated with that song. Interestingly, the memory of music is one of the last to be affected by the devastating Alzheimer’s disease, and so people with severe memory loss of their own lives can remember every line of their favourite songs.

Music is a very big topic, and there is a lot to cover here (as is always the case with neuroscience topics). For instance, did you know that five month-old babies can react to happy songs, and by nine months they can be affected by sad songs? However, I hope this voyage into how the brain processes music has been interesting and insightful!

Thanks for reading,

Al

[alsbrainblog]

Marijuana and Memory

I mentioned in a previous post that marijuana affects our brains the way it does because the chemical THC within the drug just happens to be very similar to the neurotransmitter formed within our own brains called anandamide. By smoking weed, the user introduces this ‘anandamide-lookalike’ into their brain and triggers the cannabinoid receptors that provide pleasure usually gained by anandamide (as well as other side effects).

Many cannabinoid receptors are found in your hippocampus, a crucial brain area that regulates memory and sleep. It follows that smoking weed will introduce THC to your brain that then triggers these receptors and affects these brain functions. Research has found (Terranova et al., 1996) that blocking these receptors enhances memory function in rodents, telling us that the drug-related THC and the naturally-occurring anandamide help prevent the formation of some short-term memories by activating these receptors! 

Image source: www.quantamagazine.org

Why would the body produce a natural chemical to prevent memory formation? The answer appears to lie in the hippocampus’ other main function: sleep. When rats were given this cannabinoid receptor-blocker (known generally as an antagonist), their memory function improved at the cost of a good night’s sleep . Rats (and humans!) need an adequate sleep cycle to function properly, so good ol’ anandamide seems to be there to cut down on memory-formation so that our brains can rest properly while we sleep.

While anandamide is carefully released by the brain to keep the things ticking over smoothly, the THC introduced via smoking weed is more like a bull in a china shop, creating imbalances in the brain - leading to the symptoms felt when ‘high’. Anandamide may limit the short-term memory formation to allow for a better night’s sleep, but THC (and therefore weed) actually tends to block this formation while the user is awake!

Isn’t neuroscience cool?

-Al

[alsbrainblog]

Let’s Talk About Sex

A look at the horny side of the brain

What I find so interesting about neuroscience is how it applies to every aspect of our lives. It isn’t some swirling magical force that makes you do the things you do, it’s the hormones and transmitters in your body and brain. So I decided to look into the neuroscience of sex and sexual desire, because it’s a pretty damn interesting topic to learn about.

For easier reading, I’ve split the topic up into the desire for sex, the pleasure felt during sex, and the post-sex satisfaction...

1. Desire

The neurotransmitter dopamine is sent from the brainstem to many brain areas associated with reward. This happens with food and it happens with sex: those two most primitive desires. Cocaine-users often crave sex due to the build up of dopamine in their brains after taking the drug and thus its effects are amplified.

While it is rather difficult to monitor neurotransmitter levels inside a working human brain, it is feasible to do so with a rodent brain (using very tiny catheters). So: you have Mr. Rat in the test chamber, and a sexually-receptive Mrs. Rat in there with him; however, a barrier separates the two. The anticipation of sex involves the reward centres of his brain being flooded by dopamine. Removing the barrier and letting the sex commence will then cause dopamine levels to decrease rapidly.

Interestingly, if Mr. Rat spies a new female rat, his dopamine levels and arousal will increase once more. Lots of sex with lots of females is DNA’s greedy, narrow-minded way of getting passed on as much as possible.

The emotion centre of the brain, the amygdala, helps us in our approach to desirable things (such as food and sex). If you are aroused by your partner, your amygdala would be flooded with dopamine, providing the urge to get you to act on that arousal and have sex. Once the sex has begun, the amygala settles down as the desire has been achieved. So much complex brain activity for something that comes so naturally! 

Fun Fact!

Research has been carried out showing male Rhesus monkeys actually enjoy porn (i.e. photos of female monkeys’ bums), as demonstrated by their willingness to forego tasty juice to stare at the photos. No judgement here, monkeys, no judgement here.

He’s got booty on the brain     (inothernews.com)

2. Pleasure

Here we are: the climax, the orgasm, the payoff, the reward. Many interesting things happen in your brain before and during an orgasm.  To clarify, studying brains during orgasm is difficult, because who is really in the mood when they’re hooked up to imaging equipment? 

To begin with, back to the idea of pleasure and reward:  the nucleus accumbens is involved in our sense of pleasure, and the ventral tegmental area (VTA) is highly influential in the brain’s reward pathway - so it is no surprise that these areas become more active during an orgasm. Biology needs to keep us eager to procreate, and orgasms are a pretty good method for this.

The anterior cingulate, the ventromedial prefrontal cortex, the parahippocampal gyrus, and the poles of the temporal lobes: these words may sound like scientific gibberish, but these areas of the brain show a decrease in activity when we orgasm. What’s interesting is that the anterior cingulate is involved in monitoring mistakes, the ventromedial prefrontal cortex in thinking about ourselves and what we fear, the parahippocampal gyrus in representing the environment around us, and the poles of the temporal lobes in the organisation of our knowledge of the world.

When we orgasm, all these brain areas show a drop in neural activity, indicating that the intense pleasure we feel is also coupled with a transcendent experience that takes us away the worries of life and even blurs the boundaries between our body and the environment around us.  In other words, sex can take our mind away from the blob of flesh, bone, and worrying brain that we consist of, and into nothing but unthinking, temporary bliss.

3. Satiation

Orgasms tend to lead to an emotionally-satisfied state, where you lie there and feel content for a little while. It is likely we can thank prolactin, oxytocin, and beta-endorphins released in the brain for this feeling. 

Prolactin counteracts the effect of dopamine and decreases the levels of the sex hormones (oestrogen and testosterone). This is most notable in men, who experience a refractory period after sex where they feel little sexual desire whatsoever. Guess what! Drugs that inhibit prolactin are being researched as we speak so that men can keep on riding that sex train as determinedly as women.

Oxytocin, the ‘trust’ hormone that is released to form bonds between people, acts as the ‘cuddling’ hormone here. When you and your partner lie in bed together, post-orgasm, and share a lovely cuddle, you can thank the recently-released oxytocin flooding your brains. 

The beta-endorphins lower bodily stress, helping you relax and feel euphoric. Sex is well-known for being a stress-reliever!

Pillow talk

I hope this has been an insightful wander through the brain of a sexually-active person. It may be a slightly taboo topic, but sexual desires are completely natural and understanding the brain’s wiring behind these desires is fascinating - and I hope you agree!

Thanks for reading

-Al

[alsbrainblog]

Let’s Appreciate... The Basal Ganglia

What is it?

A group of brain cell clusters (AKA nuclei, AAKA ganglia) in your forebrain that dabble in voluntary motor movements, emotion, cognition, learning, and routine behaviours. However, there is still much to learn about its function.

Here they are: the basal ganglia (purple bits). Don’t worry about all their scary names

Image source: Wikimedia

What’s so important about it?

The ��Action Selection Hypothesis”. So, your cortex (the most ‘advanced’ part of your brain) provides the basal ganglia (BG for short) some potential actions to carry out at a given time, the BG then acts as the selector of the best action. Over time, your basal ganglia will be trained to pick the actions that have been most rewarding in the past.

What happens if it is damaged?

Many behavioural disorders such as Tourette syndrome and obsessive-compulsive disorder (OCD), and movement disorders such as Parkinson’s disease can occur with neurological damage to the BG - highlighting its importance within our brains.

Let’s look at Parkinson’s for a second... 

one of the symptoms of the disease is a lack of action selection: sufferers tend to show a lack of emotion or facial movement that may be due to the breakdown of the BG’s action selection abilities

another symptom is the significant tremor: most likely due to the severe decrease of dopamine within the BG that interferes with its ability to control motor areas of the brain to allow for smooth movements

What has it done specifically for me in the last 20 minutes?

Hopefully this is quite clear by now! In theory, your cortex ‘suggested’ to your BG that you move your mouse/click on my blog/scratch your nose and your BG gave these actions the all clear. Who knows how many potential actions were axed?

Your BG was involved in the eye movements you used to look around the screen, as well as regulating the focus of your short-term memory (for example, do you look at the clock and make note of the time or does it slip your mind, meaning you have to glance again in a second?) and the routine grinding of your teeth that you do without realising.

In summary, the basal ganglia is a complex beast, and I hope I’ve managed to explain its role within the brain in a simple manner. However, it still holds a fair amount of mystery within the field, and it spans across a wide variety of overlapping brain functions just to make things extra confusing for us!

[alsbrainblog]

Let’s Talk About Drugs

Specifically, I’m going to talk about psychoactive drugs - those that change the way your brain functions and alter your behaviour, mood and/or perception. These drugs are popular due to the fact that taking them often results in a pleasant change in mood/consciousness (a ‘high’) and therefore reinforces the use of the drug - and the danger lies in taking the drug repeatedly despite any negative consequences.

Image credit: Popular Science

This post isn’t a moral lecture on your health, but a look into the mechanisms of how different drugs affect your brain. To put it simply, psychoactive drugs alter the levels of neurotransmitters (chemical messengers between neurons) in your brain. So, firstly, let’s look at how alcohol makes us feel ‘drunk’:

Alcohol

The excitatory neurotransmitter dopamine is increased in the reward centre of your brain, causing the feeling of pleasure we experience when drinking (and keeps us coming back for more)

The inhibitory neurotransmitter GABA is increased in your brain, leading to sluggish movements and slurred speech (sound familiar?)

The excitatory neurotransmitter glutamate is suppressed, also slowing down your brain. People tend to feel their inhibitions disappear when drinking, leading to increased confidence and stupid decision-making

Blackouts can occur, where the brain doesn’t even create and store new short-term memories. You may have no recollection of the events you were a part of thanks to all that wine you drank...

Cocaine

Cocaine is one hell of a blocker. It blocks the reuptake of three types of neurotransmitters in the brain, and therefore leaves them to build up in our synapses and amplify their normal effects:

As with alcohol, cocaine induces a feeling of pleasure due to the increase in dopamine - leading to dependency

The build up of serotonin causes feelings of confidence and a happy ‘buzz’

The build up of noradrenaline leads to the wired, energetic behaviour of cocaine users -as this neurotransmitter exists to mobilise the brain and body for action in times of stress or danger

Cannabis

The neurotransmitter anandamide (from ananda, the Sanskrit word for “bliss”) activates cannabinoid receptors in the brain, which affect memory, coordination, learning and problem-solving; then cannabis comes along...

Cannabis users introduce tetrahydrocannabinol (THC) into the brain, which mimics the actions of anandamide. THC binds to the cannabinoids in your:

memory centre (the hippocampus) and interfere with short-term memory recollection

emotion centre (the amygdala) and interfere with emotional control

hypothalamus (hormonal gland for controlling hunger, thirst, temperature etc.) and can lead to a case of the ‘munchies’

cerebellum and basal ganglia to affect your motor coordination

So there we have it. Drugs have a very real, concrete chemical basis in how they make our brains feel the way they do when they are used. It’s fascinating to think chemicals formed in various plants have the exact structures needed to slot into various receptors in your brain and lead to a whole range of sensory, mood and perception alterations.

[alsbrainblog]

The Morris Water Maze

Okay, time to talk about one of my favourite neuroscience studies. Seriously, I repeat this little neuro-anecdote often.

From the pages of the Flickr user http://flickr.com/photos/jepoirrier/139971105/in/set-72057594105461945/ 

Conceived by Richard G. Morris (when he was at the University of St Andrews because it’s the best ;)) in 1981, the maze is less of a maze and more a tank of liquid in which a rodent is placed. It does get more exciting, I promise. Rodents would rather be on land than swim; so, by placing a platform below the surface of the water, the rodent is incentivised to swim until it finds the platform and remains there. Utilising spatial memory within the brain’s hippocampus, the rodent will locate the platform with increasing speed each time it is placed in the water.

http://brainmadesimple.com The human hippocampus. Be aware that this isn’t a rodent brain, I just want to make this blog relevant to its readers haha

Right then. One protocol is to place the rodent in the water, record the time taken to find the platform, and repeat this throughout the day. As I mentioned, in a normal rodent, the time taken will decrease. On day two, the platform is moved, but the rodent soon learns where and heads straight for its location in the following trials. This is repeated over x days, observing how the first trial of each day takes longer due to the rodent having to relearn the platform’s location. However... lesion the poor rodent’s hippocampus and it will not learn the new location each day. Interestingly, if we block certain receptors (called NDMA receptors) on the synapses crucial for memory then long term memory is kaput but short term is not -i.e. the rodent is still able to remember the platform’s location recently after finding it once before, but if you make it wait a while in between then it will have forgotten.

To put this in perspective, and to summarise why I find this so fascinating, a simple drug that happens to block a minuscule receptor in our memory system can lead to an inability to learn new things in the long term. Here, specifically, in the spatial memory of rats.

www.hellobio.com

I find it rather cool that this little drug here can have such profound effects. Next time I’ll talk about how different drugs such as alcohol and nicotine meddle with our synapses to alter our behaviour.

[alsbrainblog]

One of the difficulties in understanding the brain is that it is like nothing so much as a lump of porridge

Richard Gregory

[alsbrainblog]

Case Study: Charles Whitman

In the first of a selection of case studies I intend to cover, I’d like to talk about the fascinating account of Charles Whitman. However, like many neurological case studies, it’s not pretty.

Now infamously known as the “Texas Tower Sniper”,a 25-year-old Whitman began his killing spree on August 1st, 1966, by murdering his wife and mother in their homes. Following this, he shot dead three people in the tower at the University of Texas, before reaching the observation deck on the 28th floor of the tower and sing a sniper rifle to kill people below at random. Going beyond the simple notion of an ‘evil mind’, what would drive a man to commit such an awful act?

During the investigation afterwards, officers found Whitman’s suicide note that contained the following words:

“I do not quite understand what it is that compels me to type this letter. Perhaps it is to leave some vague reason for the actions I have recently performed. I do not really understand myself these days. I am supposed to be an average reasonable and intelligent young man. However, lately (I cannot recall when it started) I have been a victim of many unusual and irrational thoughts.”

Whitman also requested an autopsy and declared how much he loved the mother he was about to murder, as well as expressing deep frustration at his condition.

An autopsy was conducted and a ‘pecan-sized’ tumour was found in Whitman’s brain. Forensic investigators suggest that the tumour may have been pressing against Whitman’s amygdala - the emotional core of the brain - likely affecting his levels of fear, anxiety and/or aggression.

http://brainmadesimple.com

So there we have it, the case of Charles Whitman. It’s not a fun story - and it definitely does not have a happy ending - but it serves as a reminder that mental health needs proper treatment just like physical health, and showcases the stark reality that unavoidable alterations to the brain can turn people into completely different, and sometimes dangerous, versions of themselves.

[alsbrainblog]

I stumbled upon this video whilst at university. Although it looks silly at first glance, this man uses mnemonics to enable you to remember the major parts of the brain and what their functions are. It’s been years and I still remember more from this guy than half the textbooks I read.

Mnemonics are a great way to memorise things. They make the information more meaningful, more visual, and provide handy associations and cues - what’s not to love?

[alsbrainblog]

Let’s Appreciate... The Reticular Formation

What is it? 

A collection of neuron groups within your brainstem that plays a crucial role in your consciousness.

Image obtained from sketchclub.com, drawn by Cari

What’s so important about it?

The Reticular Formation is what keeps you behaviourally aroused and generally aware of your surroundings. You know it’s important because it’s in your brainstem, which is where some of the most crucial brain functions lie (such as your heartbeat and breathing, those minor things). 

It’s split into three columns:  1. one responsible for making serotonin to regulate your mood 2. one responsible for motor coordination 3. one responsible for exhalation

What happens if I damage it?

There is a good chance you’ll fall into a coma. Without a properly-functioning reticular formation to keep you conscious and aware... you’ll slip into a vegetable state. Not ideal. 

What has it done for me specifically in the past 20 minutes?

Perhaps you were sat at your desk, staring at your computer screen. You adjust your posture to get more comfortable, you breath, you cough gently, a new Youtube video thumbnail grabs your interest, you lean in a little closer and sit up a little straighter, happy to watch instead of doing boring work.

You can thank our good friend, the reticular formation, for these actions that add a little comfort and arousal (non-sexual, of course) into your days.

[alsbrainblog]

The fun side of your brain

Playing. We do it a lot as kids, usually less so as adults. You wouldn’t be crazy for asking: how does it help? What is the role of playful behaviour in body and brain development?

For starters, play tends to be behaviour with no useful end goal, just for recreational pleasure. It uses up precious energy, makes animals more vulnerable to predators, and can lead to injury. There must be decent evolutionary reasons why we do it, otherwise the playful animals would died out from rolling off cliffs and squeaking their way into predator talons.

Let’s start with the easy stuff: Fitness. If your puppies are having some rough and tumble, then they’re being active, working their muscles, burning fat, and improving cardiovascular fitness. Same goes for a game of frisbee down the park with your friends.

Second: Social skills. Playing together leads to cooperation, communication, sharing, empathy, the list goes on. Have you tried building a Lego set with somebody else? You’ll run the gamut of CEO, architect, builder, motivator, detective, and even wince when your friend steps on a piece. That’s teamwork right there.

Third: Academic prowess. Stevenson and Lee (1990) highlighted the link between the short breaks that Chinese and Japenese students are given every 50 minutes at school, and the high achievements of these country’s students. Studies on rats (Gorden et al, 2003, Huber et al, 2007, etc) have shown that allowing them to play with each other leads to increased production of a protein responsible for brain cell growth and maturation -especially when playtime includes exploration.

More: Language skills, problem-solving skills, creativity, hand-eye coordination, rule-based learning, emotional maturity... playing really seems to be helpful in so many ways. For instance, playing in sand pits and water pits as a child is extremely helpful in understanding physics and the way objects behave in different environments. 

Diamond et al (1964) raised one group of rats in boring old solitary confinement (poor things) and another group within fun, toy-filled colonies... and guess what? The fun rats were found to have thicker cerebral cortices (the outer layer of the brain responsible for attention, perception, thought, consciousness, memory -basically all of the higher functions) than the solitary rats. It’s hard to do a study like this on human children, but the results would likely be the same. 

Playing is very much a beneficial behaviour. Or perhaps I wrote this whole thing to justify my videogame addiction...

[alsbrainblog]

The nervous system is full of chemical synapses: connections between neurons that involve neurotransmitters being released from one neuron activating receptors on target neurons.

Some of these receptors are activated by the transmitter acetylcholine (ACh), and it is this molecule that happens to link memory, pain, and nicotine addiction within the nervous system. The fact that all three systems use the same neurotransmitter means that one drug currently being developed by Texas A&M scientists may:

help reduce cognitive decline in patients with neurodegenerative diseases (such as Alzheimer’s)

ease pain

help smokers give up cigarettes.

Now that’s what I call a triple threat.

How One Drug Could Affect Pain, Memory and Nicotine Addiction

Texas A&M researchers work to develop a drug to enhance the function of nicotinic acetylcholine receptors.

The research is in Journal of Biological Chemistry. (full open access)

[alsbrainblog]

Learning

I’m going to start with a fundamental aspect of our brains: learning. If our brains didn’t quietly restructure themselves based on our actions, we would react the same way to stimuli no matter how times we experienced them. This way lies extinction.

From birth, most organisms have a number of learning methods, based within the intricacies of our neurons and synapses, that allow us to become more energy-efficient, knowledgeable of our environments, and more capable of catching prey/avoiding predators, for example.

I promise not to get too technical, but I’m going to briefly run over the main types of learning. I find it enjoyable to pinpoint which types of learning apply to the different behaviours and skills I’ve picked up since I was born; give it a try...

(I’m not ashamed to admit that Wikipedia was my friend here)

Habituation

Imagine an adorable little lamb. It’s new to the world and pretty much everything startles it: a gust of wind, for example, and our lamb runs straight back to its mother, trembling. Imagine if it kept this up all its life. The energy wasted running in fear at the slightest thing; it really isn’t efficient.

(fanpop.com)

Enter habituation. This is a form of non-associative learning (simply put: a change in one’s response to a single repeated event, rather than associating separate events) and helps organisms shed some ‘useless’ reflexes they may possess. No longer will the lamb fear the wind. However, habituation will not occur when the threat is real: the lamb will still fear the wolf.

Sensitisation

Here’s another form of non-associative learning. Sensitisation is simply the reverse of habituation: the more we are exposed to a stimulus, the larger the neural response. Imagine you rub your arm, feels normal right? If you keep rubbing your arm extensively, you will start to sense pain in the area. Your peripheral nerves have warned your brain that this prolonged stimulation is painful via heightened response. Then you’d feel pretty stupid. Sensitisation can bring back a response that may have been habituated, if the circumstances change.

Classical Conditioning

Classical conditioning is fairly well-known due to Pavlov’s experiments with his dogs, and is a case of associative learning. In case you’re unfamiliar, the famous experiment involved Ivan Pavlov preparing his dogs’ dinner and observing their salivation (a natural response of a hungry dog who smells its dinner). Pavlov would eventually pair the smell of dinner with the ringing of a bell.

Food smell --> salivate                       (naturally)

Food smell + bell ring --> salivate      (simple enough)

Pavlov did this enough so that the dogs had been conditioned to associate the bell ring with their dinner. Just like my golden retrievers grew to associate the word “walkies!�� with their walks; if I had been a cruel child, I could have shouted that magic word and got them excited without walking them whatsoever. Here lies the crux of classical conditioning: once this association had been made, Pavlov rang the bell (unconditional stimulus) and watched the dogs salivate (unconditional reflex) without any sight or smell of food (conditional stimulus).

Bell ring --> salivate                           (what mind trickery is this?!)

This may sound cruel, but it isn’t a surprise coming from Pavlov’s lab. This interesting New Yorker article (http://www.newyorker.com/magazine/2014/11/24/drool)                             looks at Pavlov’s extreme experiments and how he used his dogs as machines to be tested and operated on, with little concern for their well-being. Anyway, that’s a topic for another time.

(comic by Mark Stivers)

Operant Conditioning

I find operant conditioning, another form of associative learning, easy to confuse with classical conditioning. However, this one is more straightforward. When a behaviour leads to a positive outcome, we are more likely to exhibit that behaviour again; if it leads to a negative outcome, we are less likely to. Easy.

Giving your dog a treat when he sits down for you? He’s more likely to obey you next time: that’s operant conditioning. Giving a mouse a small electric shock when she presses a button? She’s less likely to press that button again: that’s operant conditioning. Praising your kid when she uses a potty rather than a nappy? You get the idea.

Imprinting

The final form of learning that I’m going to talk about is imprinting: this is a fun one. The big example that comes to mind is the Austrian scientist, Konrad Lorenz, and his work with geese. Lorenz gave the term ‘imprinting’ to the behaviour shown by newly-hatched goslings (amongst other birds), where they mentally ‘latch on’ to and follow the first moving object they see once hatched. What should ideally be their mother, can easily be a human who was nearby during the hatching - and thus a person can be followed by a string of tiny goslings they assume is their primary caregiver.

Imprinting explains why we see ducklings follow their mothers so diligently, and occurs rapidly, allowing offspring to stay safe with their parent upon hatching. Biologists will often wear bird outfits when dealing with goslings, and feed them using puppets, so as to avoid them imprinting on humans. Isn’t that amazing? Also, the Italian hang-glider pilot, Angelo d’Arrigo used his hang-glider to cause threatened birds to imprint on him and subsquently be reintroduced to the wild. I’d say that was an uplifting story but the level of pun is too much, even for me.

(http://www.pbs.org)

There we have it. I hope I haven’t scared people off with such a long post, and I don’t think I’ve been too technical. I just find it fascinating to be able to trim the daunting topic of ‘learning’ down into these distinctive and definable methods that help humans and animals alike grow to be functioning, well-adapted adults (or mature sea anemones, I’m not picky).

[alsbrainblog]

Welcome

This is an introductory post on what I hope will be an active, engaging and thought-provoking blog. I recently had a realisation: I like writing, and I like talking about the brain...so why not start my own brain blog?

I’ll try to frequently write about the facts, experiments, and anecdotes that really make me appreciate how complex and brilliant the brain is, as well as the often severe consequences of a dysfunctional brain.

[alsbrainblog]

“If the brain were so simple we could understand it, we would be so simple we couldn’t.”

Lyall Watson