Parkinson’s disease is a brain condition where cells that produce a neurotransmitter called dopamine are lost in a particular area of our brain. Once 80% of these cells are lost those symptoms that we associate with Parkinson’s disease such as movement disorder and tremor become more apparent.
It’s also a common disorder affecting 2% of those over the age of 65 and 4-5% of those aged 85 years and older.

What hasn’t been known though, is what causes these special brain cells to die. Treatment for Parkinson’s has been targeted at replacing the dopamine that the brain can no longer adequately produce, but this does not address what has caused the loss of these brain cells in the first place.

Researchers have now discovered that a particular brain toxin, which occurs naturally in the brain, may be the missing link.

The brain toxin concerned is called DOPAL. It causes another brain protein, found throughout the brain, called alpha-synuclein, to form clumps. This clumping leads to more DOPAL being produced and this is then linked to causing dopamine producing cells to die.

Hopefully this will provide another small piece in the giant neuroscience jigsaw to help us understand better what causes Parkinson’s disease.

Ref:
W. Michael Panneton, V. B. Kumar, Qi Gan, William J. Burke, James E. Galvin. The Neurotoxicity of DOPAL: Behavioral and Stereological Evidence for Its Role in Parkinson Disease Pathogenesis. PLoS ONE, 2010; 5 (12): e15251 DOI: 10.1371/journal.pone.0015251

Dopamine is a brain neurotransmitter that is associated with a number of important brain functions including motor control, emotions, feelings of pleasure and reward.

Like the story of “Goldilocks and the three bears” it’s important to have the amount of dopamine in our brain that’s “just right”.

Too little and the effects are seen in the condition of Parkinson’s disease where the cells that produce dopamine are lost.

Too much and the effects can be associated with schizophrenia, psychosis and ADHD.

When we experience something that we enjoy or feel rewarded by, such as enjoying good food, having sex or listening to music we love, our brain releases dopamine. Our brain is then primed so that when that experience reoccurs, a greater dopamine response is triggered and we are more likely to seek out that reward because it makes us feel good.

In ADHD kids (and adults) have difficulty focussing on tasks and demonstrate more impulsive behaviour.
They are also more likely to be at greater risk x 2-3 of developing addictions to drugs such as marijuana and cocaine and alcohol as adolescents and adults.

The link is thought to be dopamine. Addictive behaviour and ADHD are both associated with a disruption in dopamine transport in the brain. Other research from New Zealand indicates that the presence of a conduct disorder in those with ADHD increases the risk of addictive behaviour developing in later life.

This opens up the question as to what can parents do to help guard their children against this. At the moment parental vigilance, guidance and having frank and open discussions with their kids remains vital. Talking to your kids about how to make good choices and making them aware that they may be at increased risk and need to take care. If you already have concerns, then seeing a cognitive behavioural therapist would certainly be worthwhile. Tackling a potential problem early is crucial.

If you have a child with ADHD, what have you found useful to make him or her more aware that they are at greater risk of addiction should they experiment with drugs or alcohol?

Refs:

Steve S. Lee, Kathryn L. Humphreys, Kate Flory, Rebecca Liu, Kerrie Glass. Prospective Association of Childhood Attention-deficit/hyperactivity Disorder (ADHD) and Substance Use and Abuse/Dependence: A Meta-Analytic Review☆. Clinical Psychology Review, 2011; DOI: 10.1016/j.cpr.2011.01.006

JAMA and Archives Journals (2007, August 8). ADHD Appears To Be Associated With Depressed Dopamine Activity In The Brain. ScienceDaily. Retrieved April 8, 2011, from http://www.sciencedaily.com¬ /releases/2007/08/070806164505.htm

Your eyes meet across the room and in that instant you have made that connection. It’s taken all of 1/5th of a second for “love at first sight”.

We talk about our heart and love, but really it’s our brain, which needs to take the credit.

When we fall in love there are 12 areas of our brain all working together, releasing a cocktail of potent love chemicals: dopamine, oxytocin, adrenaline and vaspopressin.

Can’t stop thinking about the love of your life? Well that’s because your executive suite, where we use our conscious and intellectual thought, is highly activated to engage our thoughts of metaphors, body image and mental representation.

There is a difference too between the deep unconditional love between a parent and child where some common areas but also the middle part of our brain is activated.
In passionate love we use more of the reward system part of our brain as well as the executive suite, which is why thinking about the one we love makes us feel so good. Apparently it’s the same euphoria as using cocaine.

And what about when you’re not sure of the other’s affections? If you know someone likes you, you are likely to find them attractive too; more so than if you thought they only liked you a bit. But what makes someone really attractive is when there is that hint of uncertainty, that “je ne sais quoi” of possibility. So playing your cards close to your chest and not letting on how you really feel can really pique someone’s interest. Or maybe of course, he’s just not that into you.

Refs:
1. Stephanie Ortigue, Francesco Bianchi-Demicheli, Nisa Patel, Chris Frum, James W. Lewis. Neuroimaging of Love: fMRI Meta-Analysis Evidence toward New Perspectives in Sexual Medicine. The Journal of Sexual Medicine, 2010; DOI: 10.1111/j.1743-6109.2010.01999.x
2. E. R. Whitchurch, T. D. Wilson, D. T. Gilbert. “He Loves Me, He Loves Me Not . . . “: Uncertainty Can Increase Romantic Attraction. Psychological Science, 2010; 22 (2): 172 DOI: 10.1177/0956797610393745

Got a favourite song or piece of music?
Something that makes you feel really good every time you hear it?

The music I love makes me want to crank the volume up to max and dance around the room, ( out of sight of the neighbours preferably) and even just thinking about my favourites produces a greater sense of well being.

That “feel good” experience or “chill” comes from a surge in dopamine being released in our brain. This is the neurotransmitter associated with “reward” associated with other pleasurable activities such as eating and sex.

And yes, the anticipation of hearing that favourite piece does produce dopamine release in the same way as when you actually listen to it.

That intense emotional response to music produces physiological change: an increase in heart and breathing rate, change in skin conductance and temperature. The more pleasurable the musical experience, the greater the physiological response.

Researchers from McGill University have used a combination of PET and fMRI scans to show that dopamine release is greater for pleasurable music rather than neutral music.

Why this is of importance is that dopamine is a neurotransmitter for establishing and reinforcing behaviours that enhances our ability in evolutionary terms to survive.

Using this combination of scanning techniques enabled the researchers to demonstrate how different systems of the brain can link to work together. Firstly the experience or anticipation involving the cognitive and motor systems and secondly the emotional component involving the limbic part of the brain. It was also the first time they were able to show a tangible and measurable response of dopamine release to an abstract reward.

So, next time you are set to enjoy an all time favourite song or classical piece, crank it up, sing along and savour the accompanying surge of dopamine associated with it.

Ref:
1. Valorie N Salimpoor, Mitchel Benovoy, Kevin Larcher, Alain Dagher, Robert J Zatorre. Anatomically distinct dopamine release during anticipation and experience of peak emotion to music. Nature Neuroscience, 2011; DOI: 10.1038/nn.2726
2. Valorie N. Salimpoor, Mitchel Benovoy, Gregory Longo, Jeremy R. Cooperstock, Robert J. Zatorre. The Rewarding Aspects of Music Listening Are Related to Degree of Emotional Arousal. PLoS ONE, 2009; 4 (10): e7487 DOI: 10.1371/journal.pone.0007487

A little ray of sunshine for Parkinson’s disease may lie with Vitamin D.

Vitamin D is the vitamin we obtain through the action of ultraviolet light on our skin. Most of the vitamin D produced is then bound in the blood and only a tiny fraction remains free and able to bind to specific vitamin D receptors now known to be located in a number of target organs in the body including the brain.

Not only that, but the area of the brain with the highest density of Vitamin D receptors is in the Substantia Nigra. This is where highly specialized cells produce Dopamine, the brain neurotransmitter vital for regulating our mood, concentration, motivation and voluntary movement.
In Parkinson’s disease many of these highly specialized cells die and the loss of Dopamine manifests itself in the form of tremor, rigidity of movement, slowness of gait and cognitive decline. Plus, thirty percent of people with Parkinson’s disease develop dementia.
It is the second most common neurodegenerative disease in Australia and remains one of the most poorly understood.

So where does Vitamin D fit in with Parkinson’s disease?

The answer to that is not yet certain, but a recently published study has linked having a higher level of Vitamin D with up to a 65% reduction in the risk of developing Parkinson’s.

These results were in a long prospective study by Paul Knekt in Finland. He showed that in a group of 3173 people aged 50 to 79, followed up over a 29 year period, those with a higher level of Vitamin D had a 65% lower risk of developing Parkinson’s compared to those with the lowest levels.

However it should be noted that all of the subjects in this study actually had lower levels of vitamin D than is recommended. This may reflect the fact that Finland is not a country associated with a lot of sun exposure for its residents. So the suggestion is that having a lower level of Vitamin D may be a predisposing factor to an increased risk of Parkinson’s disease. There is no suggestion that having a low level is in fact a cause. The study remains a starting point to determine whether giving Vitamin D as a supplement would be useful.

One of the problems recognized is that Vitamin D deficiency is widespread, even in a sunny country such as Australia. It has been reported that half to two thirds of teenagers and adults in the US have lower than desirable levels. Because it is very difficult to get sufficient Vitamin D through our diet, having adequate sun exposure is essential to help us achieve and maintain a healthy level.

How much time do we need in the sun?

Five to fifteen minutes of sunlight exposure to the face and upper arms, four to six times a week is thought to be sufficient to prevent deficiency.
Those particularly at risk of deficiency here in Australia include the elderly living in residential care and dark skinned women, especially those who are veiled. The use of sunscreen (essential to protect us from skin cancer) unfortunately prevents the synthesis of Vitamin D in the skin. Application of Factor 8 will prevent up to 95% of Vit D conversion, so a short exposure without sunscreen is recommended and outside the high-risk times of 10 am to 3 pm.

Can we get Vitamin D from our food?

We can derive a limited amount of Vitamin D from food sources. However in cases of deficiency taking a supplement would be recommended.

Vitamin D2 can be found in:

Fatty fish such as mackerel, salmon and herring
Fortified margarines
Cod liver oil
Liver
Eggs

The role of Vitamin D in the brain

The association of Vitamin D and Parkinson’s disease is intriguing and as yet not fully explained. It is believed that Vitamin D acts as a hormone rather than a vitamin, in addition to its role in bone metabolism.

Current thinking is that it may exert a neuroprotective effect through its antioxidant properties, calcium regulation of nerve cells, enhanced nerve conduction, detoxification and immunomodulation.

A UK study looked at Vitamin D levels of a group of 858 Italian men and women over the age of 65 years. Of those with dementia, 50% were vitamin D deficient. Moreover, those with the greatest deficiency had a 60% increased risk of suffering cognitive decline over the 6-year follow up period.

The role of Vitamin D relating to Alzheimer’s disease was looked at in a 2008 study where 100 people with Parkinson’s disease were compared to 100 subjects with Alzheimer’s disease and 100 healthy controls. Here the fraction of patients with the lowest levels of Vitamin D was most marked in the Parkinson’s group (23%) compared to the Alzheimer’s group (16%) and healthy group (10%) indicating support for the notion that Vitamin D plays a role in affording some neuroprotection.

Meanwhile it remains prudent to ensure that we obtain adequate sun exposure to keep our Vitamin D levels up. So go on, it’s time to enjoy some time in the sun.

References:
Emory University (2008, October 17). Lack Of Vitamin D Linked To Parkinson’s Disease.
Archives of Neurology [2010] 67 (7) : 808-811 (Knekt P, Kilkkinen A, Rissanen H, Marniemi J, Sääksjärvi K, Heliövaara M.)