The professor softly circles a small section of the pork chop-sized sample of brain in front of me.

“This is the hippocampus,” she says. “It is where your father made his memories.”

Those memories include the poetic prose from the King James Bible, a thousand pictures of a conflict-free Afghanistan and fond memories of Oxford’s Dragon School.

Standing in this lab in Oxford, “fixing” chemicals gently wafting into my nostrils, all my professionalism drains away and tears prick my eyes.

Nicolas John Owen died in March this year, aged 70, after a 40-year battle against the debilitating symptoms of multiple sclerosis.

Before he died he agreed to donate his brain to science and a few months later, after my initial grief had subsided, I asked the Thomas Willis Oxford Brain Collection – the centre where it was stored – whether I could visit their laboratory and see them at work.

Not many people know their brains can be of use after their death and I wanted to give the centre some much-needed publicity. But as soon as I set eyes on father’s brain, I feel guilty, as if I’m somehow intruding on his personality.

It’s an understandable reaction. The brain is unlike any other organ. You look at a heart and know it pumps blood round the body. A kidney works as a filter. But a brain is the physiological embodiment of the soul.

Functionally, it helps our body to move and feel physical pain, but it’s also what moves and pains us emotionally. Multiple sclerosis – which affects around 85,000 people in Britain – damages myelin, the protective sheath surrounding nerve fibres, and leads to the body’s immune system attacking itself.

My father’s first symptoms – temporary paralysis and numbness – presented themselves when he was still in his early 30s but, newly married and with a baby on the way (me), he refused to let MS spoil the party.

He was a salesman for Pergamon Press, a publishing house that specialised in scientific books and journals. The job took him to Africa, the Middle East and Athens, where we lived for a while in the mid-1970s. Postcards sent to me while he was abroad are a testament to the great enthusiasm he had for his work and the deep love he felt for his family.

It was only in the ’80s, when we were back in Britain, living in Buckingham, that MS began to take its toll. Sudden attacks of tremoring and spasticity would suspend his movements, leaving him angry and frustrated. He hated giving MS recognition, rarely mentioning it by name. Instead, when his legs let him down, he’d refer to “this damn thing” and slap his thigh, or attempt humour with comments about how “the mind is willing but the body ain’t”.

He was a man of big emotions. He cried during films like Goodbye, Mr Chips, he worshipped God soulfully and thoughtfully, he belly-laughed at The Goon Show and Hancock’s Half Hour, and he lapped up knowledge.

Don’t get me wrong: there were moments when my father was the bane of my life. I was once severely reprimanded for calling him a “crippled idiot” at a large Boxing Day family gathering. I was an embarrassed teenager, frustrated by the wobbly results of his unrelenting determination to beat MS. My father just chuckled and later used the term as a fond nickname for himself.

But he couldn’t stave off the disease forever. In the ’90s, MS finally stopped him walking and over the next decade, he started to lose function throughout his body.

He suffered the humiliation of incontinence, the frustration of not being able to read a book when his arms became weak and dysfunctional and, finally, deep depression when he could no longer hold himself up in a wheelchair and became resigned to a bed.

For someone who was once so erudite and active, he must have been living hell on earth, bar my mother’s constant loving attention and the regular thunderous visits from his grandchildren.

His decline was all the more poignant for me because I found out, just before my university final exams, that I had multiple sclerosis too.

An MRI scan confirmed that I had the disease, albeit the less serious relapsing-remitting kind.

If anything, having a dad who I’d watched decline has fortified me. I will not be beaten. I have had no symptoms since that initial episode in 1995, and it amuses me when people first discover I have the disease – so stunned are their reactions.

About 12 years ago, I was conducting a series of interviews at Oxford’s Radcliffe Infirmary, in my capacity as a journalist for the Oxford Mail. The organ retention scandal at Alder Hey Children’s Hospital in Liverpool was in the news and the doctors I spoke to told me they were concerned that the bad publicity would significantly reduce donor numbers. Brains, they said, were particularly valuable; those ravaged by MS especially so.

I repeated this to my father. The doctors had told me the brains of family members would help inform research into the genetic causes of MS, so we both decided to donate.

The Thomas Willis brain bank – one of 14 across Britain – has about 5,000 examples of this most mysterious and enigmatic of human organs, but it needs more to continue its vital work into numerous neurological diseases and illnesses, including MS, Alzheimer’s and Parkinson’s. As a family, we feel immensely proud of my father’s contribution to this cause.

In the laboratory, Emeritus Professor of Neuropathology Margaret Esiri explains why the brain is so vital. “We can’t look at the brain during life, except through imaging,” she says. “But you can’t get down to the molecular level using imaging, so the only chance we get is after a person has died.”

Studying the molecular structure of brain tissue, comparing and contrasting that of MS sufferers and others and researching its genetic make-up is helping scientists discover what causes this distressing illness. Pinpointing certain molecular behaviour can also direct researchers towards possible treatments.

The research would benefit, in particular, from more samples from young people, as well as controls – brains from people free from neurological conditions. Although there are 16 million people on the NHS Organ Donor Register, the brain is not one of the organs listed.

“There’s a sense of immediate altruism attached to [conventional] organ donation,” says Prof Esiri. “Someone else is being helped directly. Brain donation is a more distant form of altruism.”

Relatives of those who do donate their brains draw immense comfort from knowing that the organ is being used to help research.

It’s fair to say my father took a relaxed approach to academic study, and he came to regret it. I know he would be proud that his brain has finally been put to work within the colleges of Oxford University.

Maybe others would be too.