.

  • Written by Jenny Graves, Distinguished Professor of Genetics, La Trobe University
Male and female brains are different at every level. Science is continuing to uncover how these differences affect health and disease. From shutterstock.com

Parkinson’s disease, a debilitating neurodegenerative disease common in elderly people, is twice as prevalent in men than women.

A new study published this month suggests the sex gene (SRY on the male-specific Y chromosome) plays a role in the loss of dopamine-making neurons that underlies this disease.

As well as providing a spectacular example of how genes act differently in male and female brains, this discovery may lead to a new treatment option for men suffering from Parkinson’s disease.


Read more: Not just about sex: throughout our bodies, thousands of genes act differently in men and women


Sex and disease

Many diseases are more common in one sex than the other. For example, multiple sclerosis and other immune disorders are more common in women than men. Parkinson’s disease, and several mental health conditions such as schizophrenia and autism, are more common in men than women.

Treatments, too, may be differently effective in men and women because of differences in expression of genes important for drug metabolism.

The bases of these sex differences are often unclear. Is it a hormonal difference that makes men and women differently susceptible to diseases, and differently amenable to treatment? For instance, the sex difference in Parkinson’s disease was previously attributed solely to the protective effect of the hormone oestrogen in female brains.

But as well as hormonal differences, we now have reason to believe genes on sex chromosomes may directly affect the brain.

Parkinson’s disease

Parkinson’s disease is a growing problem, particularly with an ageing population. Nearly one in 300 Australians live with Parkinson’s disease. It usually appears in later life as problems in starting and maintaining voluntary movements, and may be accompanied by severe tremor.


Read more: What causes Parkinson's disease? What we know, don't know and suspect


Parkinson’s disease is caused by a loss of neurons responsible for making dopamine, a hormone and neurotransmitter that sends messages to other nerve cells. Symptoms appear when 70% of these dopamine-synthesising cells have been depleted. We don’t understand how these neurons are lost, but expect the effect of loss on motor function is due to the curtailed dopamine production.

Parkinson’s disease is progressive and incurable, but the symptoms may be ameliorated and delayed by medications that boost dopamine or substitute for it.

A lack of the neurotransmitter dopamine is known to be associated with Parkinson’s disease. From shutterstock.com

SRY and Parkinson’s disease

In humans and other mammals, females have two X chromosomes (XX), and males a single X and a male-specific Y chromosome (XY). SRY is the master gene on the Y chromosome that determines the male sex of a baby in the embryo.

But research has found SRY seems to be active in other parts of the body, too. In mice and rats, SRY is active in the brain, and in humans it’s expressed in several tissues and organs, including the brain.


Read more: What makes you a man or a woman? Geneticist Jenny Graves explains


SRY has been found to be expressed at abnormally high levels in the brains of mice and rats mutated to have symptoms of Parkinson’s disease, and in animals where the disease was induced by chemical treatment.

Previous work showed overactivity of the SRY gene destroys neurons that synthesise dopamine. We’re not entirely sure how this happens, but given the link between dopamine production and Parkinson’s disease, it might partly explain why Parkinson’s disease affects males more commonly than females.

This new study now shows that interfering with SRY expression in the brains of rodents with Parkinson’s disease ameliorates the severity of symptoms. Vince Harley and Joohyung Lee from the Hudson Institute in Melbourne found that quashing SRY action prevented or mitigated the reduced mobility of male animals with Parkinson’s disease.

For every woman who has Parkinson’s disease, two men have it. From shutterstock.com

So, suppressing the activity of SRY in neurons of Parkinson’s disease patients could ameliorate their symptoms.

This sort of a cure may be many years away, but it would have a huge impact on the quality of life of thousands of men in Australia living with Parkinson’s disease.

Sex and the brain

Male and female brains really are different at every level; molecular, cellular, and behavioural. For 60 years this has been attributed to sex hormones. But we’re beginning to find that genes may also have direct effects.

A recent analysis of the activity of most of the 20,000-odd genes in the bodies of hundreds of men and women showed that more than one-third were expressed much more highly in one sex than the other. This sex bias was not limited to sex organs, but was obvious at many other sites, including the brain.

The effect of SRY in the brain is a strong demonstration that male and female brains are genetically different in health and disease, and a reminder we must take account of sex differences in diagnosing and treating disease in men and women.


Read more: Differences between men and women are more than the sum of their genes


Jenny Graves receives research grants from the Australian Research Council

Authors: Jenny Graves, Distinguished Professor of Genetics, La Trobe University

Read more http://theconversation.com/the-sex-gene-sry-and-parkinsons-disease-how-genes-act-differently-in-male-and-female-brains-121764

Better pay and more challenge: here's how to get our top students to become teachers

Relative to other careers, bright students who were surveyed didn't see teaching as coming with career challenges. www.shutterstock.comAustralia’s young high achievers are turning their backs o...

Peter Goss, School Education Program Director, Grattan Institute - avatar Peter Goss, School Education Program Director, Grattan Institute

Does anyone have a pad? TV is finally dismantling the period taboo

New attitudes show periods might finally be coming of age. July Prokopiv/ShutterstockLast week, menstrual pad brand Libra launched their Blood Normal commercial in Australia, running it during prime ...

Lara Owen, PhD Candidate, Monash University - avatar Lara Owen, PhD Candidate, Monash University

How doctors convinced the world the planet was worth fighting for

International Physicians for the Prevention of Nuclear War, which won the Nobel Peace Prize in 1985, is one example of doctors' involvement on the political stage. Wellcome Images/Wikimedia CommonsLas...

James Dunk, Research Fellow, University of Sydney - avatar James Dunk, Research Fellow, University of Sydney

After 2 festival deaths, the NSW government rushed through a new drug homicide crime. But it may do more harm than good

The first of its kind in Australia, the offence of 'drug supply causing death' carries a maximum 20 year sentence. ShutterstockAs the state election loomed last year, the NSW government rushed through...

Elyse Methven, Lecturer in Law, University of Technology Sydney - avatar Elyse Methven, Lecturer in Law, University of Technology Sydney

Voter turnout at New Zealand local elections keeps falling, but paying people to vote could backfire

Rather than encouraging people to become better citizens, rewards and fines can actually reduce peoples’ natural tendencies to do the right thing by others. from www.shutterstock.com, CC BY-NDLa...

Julia Talbot-Jones, Lecturer, Victoria University of Wellington - avatar Julia Talbot-Jones, Lecturer, Victoria University of Wellington

The digital human: the cyber version of humanity's quest for immortality

If it were possible to download the neural networks of a human brain, could we preserve a computer simulation of that person? from www.shutterstock.com, CC BY-NDImmortality has been a topic of discuss...

David Evans Bailey, PhD Researcher in Virtual Reality, Auckland University of Technology - avatar David Evans Bailey, PhD Researcher in Virtual Reality, Auckland University of Technology

Three ways to fix the problems caused by rezoning inner-city industrial land for mixed-use apartments

Show Works, based in the Melbourne suburb of Preston, makes dance floors, dance equipment and theatre scenery. Andrew Warren, used with permission, Author providedSince 2000, planning authorities in A...

Carl Grodach, Professor and Director of Urban Planning & Design, Monash University - avatar Carl Grodach, Professor and Director of Urban Planning & Design, Monash University

Interesting Ways to Have Fun Without Leaving Your House

Having fun isn’t synonymous to going out. This is what a lot of people should know if they’re looking to do fun things without leaving the comfort of their homes. The truth is that spending time...

News Company - avatar News Company

Become Independent and Install a Solar Power System in your Property

We are certainly living in a very exciting time, and when you consider the technological advances we have witnessed in the last 50 years, it really is amazing. In the 1960s, the Internet emerged and...

News Company - avatar News Company

The Amazon is on fire – here are 5 things you need to know

Huge fires are raging across multiple regions of the Amazon Basin. Guaira Maia/ISARecord fires are raging in Brazil’s Amazon rainforest, with more than 2,500 fires currently burning. They are ...

Danilo Ignacio de Urzedo, PhD candidate, University of Sydney - avatar Danilo Ignacio de Urzedo, PhD candidate, University of Sydney

It's not just athletes who get Achilles tendon pain, but exercising is the answer

Basketball fans around the world were recently sickened by the footage of NBA star Kevin Durant’s Achilles tendon rupturing during a game. But while many think it’s only elite athletes...

Sean Docking, Post-doctoral researcher, La Trobe University - avatar Sean Docking, Post-doctoral researcher, La Trobe University

Australia's energy woes will not be solved by reinforcing a monopoly

Australia's energy market has a logjam, Sean Davis/Flickr, CC BY-NC-SAThe possibility of blackouts affecting half of Victoria has attracted plenty of attention to a document once read only by industry...

Bruce Mountain, Director, Victoria Energy Policy Centre, Victoria University - avatar Bruce Mountain, Director, Victoria Energy Policy Centre, Victoria University

Tim Fischer had his blind spots, but he was an unsung champion of an Asian-facing Australia

Amid the tributes to former deputy prime minister Tim Fischer and the stories of his authenticity, courage and quirky interests – like trains and military history – what has struck me most...

Tim Harcourt, J.W. Nevile Fellow in Economics and host of The Airport Economist, UNSW - avatar Tim Harcourt, J.W. Nevile Fellow in Economics and host of The Airport Economist, UNSW

VIDEO: Michelle Grattan on Tim Fischer's legacy - and Scott Morrison's first year

Michelle Grattan talks about the sad news of the passing of former Deputy Prime Minister Tim Fischer with University of Canberra Vice-Chancellor Professor Deep Saini. They also discuss Scott Morrison&...

Michelle Grattan, Professorial Fellow, University of Canberra - avatar Michelle Grattan, Professorial Fellow, University of Canberra

Catastrophic Queensland floods killed 600,000 cattle and devastated native species

In February, about 600,000 cattle were killed by catastrophic flooding across north Queensland’s Carpentaria Gulf plains. The flood waters rose suddenly, forming a wall of water up to 70km wi...

Gabriel Crowley, Adjunct Principal Research Fellow, James Cook University - avatar Gabriel Crowley, Adjunct Principal Research Fellow, James Cook University

Four home traps that contribute to the gender pay gap

KPMG says Australia's gender pay gap declined from $3.05 an hour in 2014 to $2.43 in 2017. www.shutterstock.comAustralia’s gender pay gap is diminishing, says a new report, but some contributors...

Emma Willamson, Adjunct Senior Research Fellow, Monash University - avatar Emma Willamson, Adjunct Senior Research Fellow, Monash University

Australia wants to install military technology in Antarctica – here's why that's allowed

Technology, such as satellite systems, can be used for both military and scientific purposes. ShutterstockThis week, the ABC revealed that the Australian Defence Force wants to roll out military tech...

Tony Press, Adjunct Professor, Institute for Marine and Antarctic Studies, University of Tasmania - avatar Tony Press, Adjunct Professor, Institute for Marine and Antarctic Studies, University of Tasmania

Why some feminists oppose allowing people to choose their sex on birth certificates

Legislation in Victoria would allow people to change the sex on their birth certificates with just a declaration, not sex reassignment surgery. ShutterstockA bill currently before the Victorian parlia...

Holly Lawford-Smith, Senior Lecturer in Political Philosophy, University of Melbourne - avatar Holly Lawford-Smith, Senior Lecturer in Political Philosophy, University of Melbourne

Plants are going extinct up to 350 times faster than the historical norm

Plant extinctions have skyrocketed, driven in large part by land clearing and climate change. Graphic Node/Unsplash, CC BY-SAEarth is seeing an unprecedented loss of species, which some ecologists are...

Jaco Le Roux, Associate Professor, Macquarie University - avatar Jaco Le Roux, Associate Professor, Macquarie University

Sick and Tired of Your Dead End Job? Try Teaching!

Tired of the same old grind at the office? Want an opportunity to impact lives both in your community and around the world? Do you love to travel and have new experiences? Teaching English is the perfect job for you! All you need is a willingness to ...

News Company - avatar News Company

The Impact of an Aging Population in Australia

There’s an issue on the horizon that Australia needs to prepare for. The portion of elderly citizens that make up the country’s overall population is increasing, and we might not have the infrastructure in place to support this. Australians h...

News Company - avatar News Company

LifeStyle

Interesting Ways to Have Fun Without Leaving Your House

Having fun isn’t synonymous to going out. This is what a lot of people should know if they’re ...

A Guide for Tenants

The cost of purchasing a home has been increasing, and the size of deposits needed, make buying pr...

Top ways for men to look after their skin

According to Jack Simmons, from Aboutmen, more and more men are taking pride in their appearance a...

Top 10 Caravan Storage Tips & Tricks

Taking caravan trips is a popular Aussie pastime, but if you have spent more than a few days in ...