Book Review: Spark, by John J. Ratey

This book explains the brain chemistry behind something most people have always known: exercise makes us feel better. But Ratey goes on to show how exercise can help us learn and fight against mental problems such as depression and anxiety. One of the most important premises of the book is that there is a relationship between movement and brain development and brain health. 

Here are some notes that I took:

Chapter One

In Naperville, Illinois. a high school began focusing on fitness more than sports. Students wore heart rate monitors when they exercised. There was a noticable improvement in learning.

Study from Virginia Tech showed that more time for study did not increase grades. Chap 1

The brain can be built up. It has a “plasticity.” Exercise fosters this quality. 

Thoughts and behavior are controlled by the interactions of the neurons. The brain is not “hard-wired.” Rather it is constantly being rewired.

Synapse – junction between brain cells. An electrical signal shoots down the axon (outgoing branch). A chemical neuro transmitter carries the signal across the gap. The dentrite receives the chemical signal and turns the signal back into electricity. If the electrical charge is high enough, it will fire a signal along its axon to another neuron. Eighty percent of signals are carried out by two neuro transmitters. Glutamate stirs up activity. Gama Amino Buteric Acid (GABA) clamps down on activity. When neurons fire together often, they become bound together. 

The following neuro-transmitters control brain activity.

Seratonin – The policeman of the brain, influences mood and aggressiveness. Seretonin drugs (Prozac) help control runaway brain activity such as depression or obsessive compulsiveness.

Norepinephrine – Controls attention, perception, motivation, arousal,

Dopamine – Learns rewards, satisfaction, attention, and movement. Ridelin affects dopamine

Most drugs work with one or more of these neuro-transmitters.

Exercise elevates serotonin and dopamine. Exercise balances neuro-transmitters. Keeping your brain in balance can change your life.

Brain Derived Neurotropic Factor BDNF – a neuro-trophin, actually builds the brain infrastructure. It nourishes neurons like fertilizer.
When we hear a new word, a group of neurons fire and “bind” together. The more that same group fires and interacts, the more bound the group becomes. This is what causes us to remember the word.

Synaptic Plasticity – BDNF sprinkled on neurons in a petri dish automatically sprouted new dendrons. BDNF also helps with the over all function of the neuron. It also works against natural cell death. It is a crucial biological link between thought, emotions and movement.

Sea Squirt – simple spinal cord and brain. After it is born it swims around until it finally attaches to something. When it does this, it eats its brain. It lives the rest of its life much more like a plant. Rodolpho Lenas says: “That which we call thinking is the evolutionary internalization of movement.”

Hippocampus – serves as a way station that bundles up a series of neuron connections related to something we have learned. When we learn a new word the prefrontal cortex lights up as well as the hippocampus.

Article in Nature – exercise increases BDNF. 

Carl Cottman: exercise sparks the molecule BDNF that affects learning. Chap 2

BDNF molecules increased in mice that exercise. Chap 2

BDNF helps neurons to sprout new branches which helped with learning. Chap 2

A Harvard study showed that less sensory stimulation reduced the brain. A cat with one eye sewn shut also showed a reduction in part of its brain. Chap 2

We were told that brain cells do not grow back. But this is not true. Advanced imaging tools showed this in cancer patients. Chap 2

Exercise does three things: 1. Improves alertness, attention and motivation , 2. Encourages nerve cells to bind to one another, essential for learning new information, 3. It stimulates production of new nerve cells from stem cells in the hippocampus.

Blood flow goes away from the brain during intense exercise. It flows back after exercise, and that is a good time for learning.

Exercise produces healthier, bushier and more connected neurons throughout the brain. Chap 2

Running rats were compared to rats who were required to do acrobatic maneuvers (running on a rail, etc.). The acrobatic rats had a 35% increase of BDNF in the cerebellum. 
The more complex the movements, the more complex the synaptic connections.

When our brain creates complex synaptic connections, they can be coopted for learning. A student who learns piano will find it easier to learn mathematics because the prefrontal cortex uses the synaptic connections created during the effort to learn piano to learn mathematics. Chap 2

This applies to yoga, ballet and things like that. Chap 2 

Stress is a threat to the body’s equilibrium. Getting out of a chair is stressful. Every thing we do when we move, learn, etc. is a form of stress. The emotions that we feel when we have stress due to a job loss, for example, are the result of many neurons firing. The difference is a matter of degree. Chap 2

Exercise controls the emotional feelings of stress. Neurons get broken down and built up just like muscles. Stressing them makes them more resilient. Stress and recovery. Chap 2

In limited doses, stress causes brain cells to over compensate. Neuro scientists call this Stress Innoculation. Challenges allow us to strive and grow and learn. Stress is a necessity. Chap 2

The amygdala assigns intensity to incoming information. Any strong emotional state can stimulate the amygdala. The emigdyla connects to many parts of the brain. The emigdyla triggers hormones such as adrenelin. The amygdala can also tell the brain to remember certain sensory experiences. Because of this we can actually set off the stress response simply by imagining a stressful situation. We can think ourselves into a frenzy. But mind affects the body. But the body can also affect the mind. Chap 2

Stress Response: Epinephrine causes the body to focus and increases blood pressure. Endorphins are released to blunt pain. Less important biological functions stop. The digestive system shuts down. The mouth stops producing syliva. The bladder muscles relax (causing you to pee your pants?) Your muscles and your brain get stiff. All this causes us to freeze. Chap 2

Norepinephrine and dopamine also causes us to focus. This is why these drugs are used to help students who can’t focus. Epinephrine causes the production of glucose which is the fuel for the brain. Cortisal also causes the production of glucose. It also triggers the process by which used energy is replaced by stimulating the production of fat. This is why marathon runners sometimes have a little belly fat despite all their training. Chap 2
Procrastination leads to stress. Stress unleashes the stress response which includes norepinephrine and dopamine to cause us to focus. After this they can sit down and do the work. 

Chapter Three

Paleolithic Rhythm: As hunter/gatherers we had periods of intense stress.
Our output of energy per unit of body mass is less than 38% of our Stone Age anscestors. (How would he know this?) Even if we eat the number of calories the government recommends and exercise 30 minutes a day, we would expend half the energy for which our genes are encoded (We are designed to burn more energy.). Paleolithic man walked 5-10 miles on an average day. There is a mismatch between our lifestyle and our genes. Chap 3

We watch too much news. This heaps on the stress. But we think we can handle it. Then we try to relieve it with food or alcohol. Chap 3

Stressful events trigger stress responses that include the production of glucose. This is why we are often hungry when stressed. Chap 3

Isolating rats increased stress hormones. It is stressful to be shunned or isolated. Adding physical activity causes us to become more socially active. It boosts our social lives. Chap 3

Mice and rats that were fed less lived up to 40% longer than others. 

Brain Derived Neurotropic Factor - BDNF - is a big focus of brain scientists. Exercise increases this growth factor and others. Chap 3

Antioxidants often have toxins. They induce a little stress. Broccoli does this. Broccoli does not have enough antioxidants to have a positive effect. The toxins cause mild stress which challenges the cells by producing unwanted waste. Chap 3

2004. Joshua B Folks. Univ of Southern Mississippi. Students with anxiety were put into two groups. One group did mild exercise. The other did more demanding exercise. Rigorous showed more benefit. The theory is that we become more comfortable with a higher heart rate and respiration rate and do not consider it noxious. Chap 3

Anxiety is fear. Fear is the memory of danger. The amygdala tags sense experiences associated with danger and burns them into memory. But the prefrontal cortex tells the amygdala to back off. If this doesn't happen, we can become overwhelmed by too many “fears.” Chap 3

Classical musicians sometimes take beta blockers to keep them from sweating and becoming too tense. chap 3

Chapter Four

For many years doctors thought that exercise made anxiety worse. However many studies showed the opposite. Andreus Brooks showed that people with anxiety improved with exercise that was gradually increased. They did as well as another group that took clomipramine. The author recommends both. This is particularly important with children. Kids with anxiety are more likely to develop depression later in life. He also recommended exercising with another person. This affects serotonin. Rigorous exercise for at least 15 minutes per day. Exercise may not be able to replace medication. The more you engage with the world, the more you can cope with the anxiety. Talk therapy is also important. Chap 4

Depression is identified by a psychological test and then trial and error with drugs. What is the biological cause of depression? Monoamine neuro transmitters: norepinephrine, dopamine, serotonin. Monoamine Hypothesis: Depression is caused by a deficit in these three neuro transmitters. 

Wiki: norepinephrine
The general function of norepinephrine is to mobilize the brain and body for action. Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in the so-called fight-or-flight response. In the brain, norepinephrine increases arousal and alertness, promotes vigilance, enhances formation and retrieval of memory, and focuses attention; it also increases restlessness and anxiety. In the rest of the body, norepinephrine increases heart rate and blood pressure, triggers the release of glucose from energy stores, increases blood flow to skeletal muscle, reduces blood flow to the gastrointestinal system, and promotes voiding of the bladder and large intestine.

The author was doing research on the medicinal approach. He saw an article from Norway about treating depression with exercise. In the 1970s there was running craze. Running increased endorphins. These are stress hormones that helps ignore pain. However endorphins produced by exercise cannot pass into the brain. But there some endorphins that are produced in the brain. Chap 4

Mind, brain and body all work together. Chap 4

Study of 8,000 beginning in 1965 showed that those who exercise had less depression. Dutch and Finnish studies showed similar results. There is an inverse relationship between exercise and depression. Chap 4

Prozac was one of the first drugs known to affect Seratonin. Chap 4

Selective Seratonin Reuptake Inhibitors (SSRIs). It prevented recycling of Seratonin. It squelched negativity and boosted self esteem. It doesn't work for everyone. Side affects: Lack of sex desire. Muzzling sexual desire can affect our overall passion for life. It can be difficult to withdraw from them. Chap 4

Exercise elevates levels of Norepinephrine. It wakes up the brain. It boosts Dopamine which improves mood and feelings of wellness. It jumps stars the attention system. Seratonin is affected by exercise and affects mood, self-control and self-esteem. It affects the hipocampus and learning. Chap 4

SMILE - Standard, Medical, Intervention, and Long-term Exercise Study 1999 James Bloomenthal - Exercise pitted against Certyline (Zoloft) Three Groups: 1. Used Zoloft 2. Exercised 3. Did Both. 

The exercise group did walking or jogging at 75% of their maximum heart rate for 30 minutes with 10 minute warmup and 10 minute cooldown three times a week. Results: All three groups showed a drop in depression. Conclusion: Exercise is as effective as medication. 

One third of depressed people achieve full remission with anti-depressants. One third feel better but have problems with fatigue. They have the shadows of depression. Chap 4

Norepinephrine, Dopamine, and Seratonin are neurotrasmitters. They can only do so much if the actual structure (good connections) of the neurons is decreased. Depression has shown to decrease neuron developement and adaptation in the hippocampus and prefrontal cortex. Depression affects learning at the cellular level. 

2005, Genome Biology, Alexandar Nikolesku see depression as a survival instinct. In an environment void of hope, the body conserves resources. Keep still and stay out of harm’s way. 

Chapter Five

The best kind of behavioral therapy is just to do something, go outside, go for a walk, do something. Exercise reprograms the prefrontal cortex. 

Even people who have a negative attitude toward exercise report a positive feeling immediately after exercise. 

It is good to exercise that in a setting that promotes social interaction. 

Medruca Trivetti and Andrea Dunn - Five Groups - Calories burned per body weight per week - At the end of three months the group that did high intensity exercise (1400 calories/week in 3-5 sessions or 8cal/lb) cut their depression in half. The low exercise group that burned 560 calories/week or 3 cal/lb showed results that were only a little better than those who did no exercise. 

Public health recommendation for exercise level is 30 minutes per day at moderate intensity. 

Multiply your body weight by 8 to figure out how many calories you need to burn a week (3-6 workouts) to be in the high intensity category.

Victims of depression often have sleep disturbance… Sleep inertia… Either trouble getting going or stopping. The key is to get moving and to do it everyday. 

Omega 3 Supplements are proven to help depression. 

Loosen up brainlock and go take a walk.

Move the body and the brain will have to follow. Trick the brain into coming out of hibernation.

Chapter Six - Hyperactivity

ADHD - First defined in the Third Edition of the DSM of 1980.
Hyperactivity is found more often in boys.
These kids need to be moving. They tend to do well in sports.
In adults it can show up in road rage. They often struggle with impatience. Inattention or distractability is the constant in ADHD.

Movement and attention share overlapping pathways.

2006 Arthur Kramer University of Illinois, MRI scans showed that walking 3 days a week for six months increased the volume of the prefrontal cortex in older adults. Also improvement in working memory.

Exercise increases levels of norepinephrine and dopamine. 

The best approach is to exercise in the morning, and then to take the medication an hour later. Exercise can lower the amount of medication needed. 

Arrange your day to keep things focused. Try to keep moving the ball forward rather than allowing it to ricochet off the walls. 

Many ADHD people are using coaches to help them with this.

Chapter Seven - Addiction

Sex increases dopamine levels 50-100%. Cocaine sends dopamine skyrocketing 300-800% beyond normal levels. It’s not just about pleasure. Dopamine is the key factor in the reward system. Dopamine is involved in wanting but not in liking. One of the functions of the prefrontal cortex is to decide between risk and reward. Cocaine is known to diminish the prefrontal cortex. The prefrontal corex is not fully developed until in the twenties. Drug use before than can leave a person with an under developed prefrontal cortex.