Many people feel helpless when they, or someone they know suffers brain damage, either from injury, a stroke or a degenerative disease such as Alzheimer's or Parkinson's.
As people live longer, the prevalence of degenerative brain disorders is increasing.
However, the brain has a remarkable ability to adapt and adjust to situations - that's why we learn things, says Prof Cliff Abraham, director of the Brain Health and Repair Research Centre of the University of Otago.
Although some parts of the damaged brain may never be recovered, there's a growing awareness that the brain can arm itself against future damage and also repair itself, at least to some extent, after damage, he says.
There's a lot of information available about keeping our hearts and bodies healthy, but there is not so much about keeping our brains healthy. Fortunately, what's good for the body is good for the brain.
"It may seem obvious but people don't always connect the two. Good diet, physical and mental exercise, keeping weight under control and enough sleep are good for the brain, but smoking, illegal drugs and too much alcohol can affect normal brain function and impair the response to damage," he said.
The brain is vitally dependent on the blood supply for oxygen and glucose, and can't survive for more than a few minutes without these. Anything that disrupts the blood supply, such as heart or arterial disease, affects how the brain functions and how it reacts to damage.
Physical exercise stimulates the production in the brain of chemicals and proteins, including anti-stress proteins and proteins that stop cell death, which help improve function and protect against damage. Thinking and mental exercise also tune up the brain, stimulating the growth of fibres and making it fitter by increasing the connections or the efficiency of the connections, Prof Abraham says.
A stimulating environment and social interaction can also help keep the brain healthy and active. Studies show animals with a rich and stimulating environment grow bigger brains than those whose environments are extremely limited, he says.
"The mind is an output of the brain, so anything that affects the mind is going to have a physical basis. Not everyone will necessarily agree with that statement, but that is a researcher's point of view.
"It's taken as a given by us that if you get people to think or behave in a certain kind of way it reflects the brain being driven to operate in that kind of way," Prof Abraham said.
Like many bodily functions, stress is good in small quantities, but not in large amounts, as it can have an effect in the brain. It releases the hormone cortisol for which there are many receptors. Activating these can impede the function of neurons, can lead to psychiatric disorders like depression, probably to cell death, and interacts badly with other things such as ageing, he says.
Memory can be severely impaired under stress. People forget a lot of things, but some can be remembered only too well and lead to post-traumatic stress disorder.
It's still controversial what happens in the brain during ageing. It seems to become less efficient in some of the things it does. The production of helpful proteins which arm its defence system goes down so it reacts worse to a event, injury or disease than perhaps it would have when it was younger. However, there didn't seem to be as much brain-cell loss as some people speculated, until late-stage dementia, Prof Abraham said.
"We know that people can age and stay mentally sharp for a long period of time, so it's not a given that everything turns to custard when you turn 65, thank goodness!"
Researchers have discovered that even in adulthood, the brain continues to make new neurons - cells in the nervous system and brain that process and transmit information by electrochemical signalling.
"It only happens in small, select areas of the brain, but there's a lot of hope that the stem cells still dividing in the nervous system give the potential that these can be tapped and harnessed in a way that will be useful for recovery from disease or damage. While it's still a long way off, it's clear the capacity is there, and depending on the severity of the disorder and so on, there may be optimism for research projects along those lines," Prof Abraham said.
• Getting your brain trim, taut and terrific
Exercise the body
Physical exercise has a protective effect on the brain and its mental processes, and may even help prevent dementia. Regular exercise promotes cardiovascular health, boosts levels of brain-protective chemicals and reduces stress. Aim for at least 30 minutes exercise a day.
Adequate sleep
Sleep recharges the brain and allows the body to rest and heal. While we sleep our brain consolidates memories. Inadequate sleep affects the way our brain cells function and can raise the risk of stroke and depression. About seven to nine hours a night is ideal.
Manage stress
High levels of chronic stress are not only bad for blood pressure, cholesterol, and other physical ailments, but it also wears away at brain fitness and overall memory performance. We can't entirely eliminate stress from our lives, but we can minimise it to improve brain health and memory ability.
Balanced diet
Our brains need a well-balanced, low cholesterol, low saturated fat diet. Studies have shown that foods rich in omega-3 are good for the brain so include fish in your diet. Enjoy caffeine and alcohol in moderation and as a general rule, good nutrition for the body is good nutrition for the brain.
Make safety a priority
Wear seatbelts, sports safety helmets and other protection.
Stay socially connected
Maintaining friends and social networks can help keep our brains healthy as we age. Living life to the fullest and having fun is an easy prescription to follow.
Mental workout
Use it or lose it! Keeping the brain active seems to increase its vitality and may build its reserves of brain cells and connections. You could even generate new brain cells. Stay curious and involved and commit to lifelong learning to keep those brain cells working.
• Be aware
Brain Awareness Week (March 14-22) is an international effort promoted by neuroscience organisations to promote public awareness about brain and mind disorders and the benefits of brain research.
The Neurological Foundation and University of Otago have a free public open day to raise awareness about neurological disorders and research on Saturday, March 21, from 11am to 4pm at the St David St lecture theatres on the corner of St David and Castle streets. Agencies such as the Stroke Foundation, Alzheimer's New Zealand and The Parkinsonism Society of New Zealand, will offer help and information.
• Public lectures
11am-noon: Prof Cliff Abraham - The past, present and future of Alzheimer's disease therapies.
noon-1pm: Assoc Prof Brian Hyland - Electric shocks and coffee: surprising directions in the treatment of Parkinson's disease.
2pm-3pm: Prof Gareth Jones - The place of stem cells in the treatment of neurological diseases: Are there cures around the corner?
3pm-4pm: Prof Harlene Hayne - My Brain Made Me Do It!
