Grandma Bluedoor lived in Doncaster near the Town Fields in a small bungalow with – you’ve guessed – a blue front door. She called it Persian Blue, hinting at Arabian Nights giddy with cedarwood and incense. But Doncaster was no Samarkand and the flapping market day stalls outside the Black Bull were far from the Kasbah. On wintery Tuesday mornings, while my mother had her hair ‘done’ in town, a procedure lasting the best part of two hours, Grandma Bluedoor painted me and my sister. Sometimes we would play cards or talk by the gas fire in the living room, its quiet reassuring hiss filling any pauses. Other days I would just listen as she spoke of her childhood in Blackpool and Wigan. Or of the war, recalling the drone of bombers flying over her house at night on their way to Liverpool. The distant thunder of explosions and the terrible chimney red glow over the horizon as the docks took their nightly pounding. Like all artists, she could paint with words as well as brushes, chalks or pastels. Sometimes we painted together. She said I had a talent and encouraged my stumbling efforts at still life – wavy fruitbowls full of livid, misshapen apples and bananas like neon hockey sticks. But often she would paint, as I sat for long hours at the window in the ‘front parlour’ wistfully listening to my friends playing football outside. My grandmother bought my patience with promises of Lemon Sherbets, Love Hearts and Spangles.

All this art was wasted on me. Although comfortably the best artist in my class, I merely went through the motions, greeting each new assignment with petulant disinterest. Each term my school report gave me an A-, the A a grudging acknowledgement of ability, but qualified by a minus that spoke accusingly of squandered talent. I was used to As. In fact, I was pretty good at most subjects. Except science.  So, with the kind of perverse logic common to adolescents, I became a scientist.

Art was for sissies. And girls. I threw my paintset in the bin with its little watercolour pots of Burnt Sienna, Vermilion, and Prussian Blue. Some sort of statement.

But, like Father Brown’s unknowing penitent, caught with an unseen hook and a long invisible line, I would one day be brought to shore with ‘a twitch upon the thread’.

I left science in 2003, three years before I was diagnosed with PD but already showing symptoms if I had only recognised them for what they were. But that’s another story for another day. For a year I was out of work, a shuffling aimless figure filling my day in that Bermuda Triangle of coffee shop, library and post office.

On my way to the library one crisp autumn morning, my attention was drawn to a flyer advertising courses in stained glass art and design. I called the number, unsure what to say.  A week later I was standiing at an easel, holding a paintbrush in my hand for the first time in 40 years. It felt like coming home.

It is sometimes said that artists are born not made, that you cannot create artists and it is useless to do so. That we are products of our nature not our nurture, the fruits of a great chromosomal waltz. The genetic blueprint that gives us blue eyes or brown hair is the same design that makes us scientists or artists, orchestra conductors or bus conductors. Our brains are wired at birth, like enormous telephone exchanges. Scary huh?

But imagine that it was not so, that we could create artists or maybe unmask latent talent, somehow fan the flickering embers of creativity.

OK, let’s go further. Imagine that we knew the particular pathways through the brain responsible for creativity. The nerve bundles that made Gustav Klimt a painter, Alan Ginsberg a poet or Miles Davis a musician.

Sound far fetched? Well try this for size. Imagine that we could reduce creativity to a single molecule, one neurotransmitter that fans the flickering flame of creation. One card from the shuffled deck.

What if you could take a pill to boost creativity, to inspire you, to move those brushes over the canvas, to make the words flow onto the page or the notes float in the air?

What if I told you that I had taken those tablets, popped those very pills this morning?

Am I a junkie?  Is this science fiction?

No. Er, that’s no to both questions. There is just such a ‘creativity pathway’, its neurotransmitter is known and there are drugs that enhance its function. Bingo!

The nerve bundle in question is the mesolimbic pathway, a great trunk of neurones that passes like a motorway from the ventral tegmental area to the busy termini of the limbic forebrain – the nucleus accumbens, the olfactory tubercle and the frontal cortex. This powerhouse of creativity is fuelled by – cue the drum roll – dopamine. That’s right, our old and much missed friend, the same dopamine that is so conspicuously AWOL from the corpus striatum.

Some of the drugs we take – the dopamine agonists – can affect this mesoliimbic pathway. In the same way that they boost dopamine function in the striatum, they also increase traffic on the ‘creativity highway’. The drugs have no sat nav. They are just as likely to find their way to the limbic forebrain as the striatum.

So what happens when you unleash a horde of dopamine agonists on an unsuspecting mesolimbic pathway? The same agonists welcomed like prodigal sons in the empty striatum, are given a more cautious reception in the bustling limbic forebrain. In the striatum, dopamine agonists are all pleases and thankyous while in the nucleus accumbens, they are storytelling  braggards, flirting with your wife and daughter while drinking your best whisky. In the striatum, dopamine agonists fill a void. In the limbic system they muscle in and further excite already busy synapses.

Many people with Parkinson’s (I am doing my best to be politically correct this week) find that their drugs open up vistas of creativity. The drugs that unlock frozen limbs also lubricate ossified imaginations. Ideas run riot. Painting, poetry, sculpture  – you name it. All down to busier mesolimbic synapses.

And this remarkable surge of creativity is acknowledged in the annual Mervyn Peake Awards, at the World Parkinson’s Congress, and in countless art groups up and down the country. Art and Parkinson’s are like peaches and cream. We paint, we draw, we stitch, write, photograph and sculpt. And it’s all down to those mesolimbic dopamine synapses, crackling and fizzing with activity.

But there is a price. In Parkinson’s there’s always a price. This same mesolimbic pathway is the one responsible for shopping, gambling and other darker behaviour. Too much dopamine and our creative urges spill over into chaos. Enthusiasm becomes anarchy. It’s a fine balance. We would all like to be Van Gogh, the painter of starry nights and sunflowers. Few would want to become the later Van Gogh staring threateningly back at us with bandaged head and missing ear. That’s the thing with dopamine – you can have too much of a good thing.

My eldest, Catherine, has plenty of dopamine. Her Art GCSE year was a riot of collage, paint, ink, gouache and paste and, for a year, Catherine’s bedroom was awash with painting paraphernalia. Our cleaner despaired. I snapped.

“Catherine, your bedroom is a disgrace. Clean it now”.

“I can’t – it hasn’t been marked yet”

“Marked? Your bedroom marked?”

“But it’s not a bedroom. It’s a mixed media installation”

Thank you Tracey Emin.