Most people take motion sensing for granted. Our eyes pick up on something moving and our brains are sent a signal to let us know something has occurred in our space-time continuum. Despite the simplicity of the task, the mechanisms allowing us this ability are incredibly complex. They have been studied for over fifty years and the neural circuitry underlying motion detection is probably the best described circuitry in the brain. Yet, researchers have not discovered all the answers.
It’s one of the guarantees of life: stress. At its core, it’s a perception of a physical or psychological threat and is designed to help us survive. But the triggers are varied and as such, there is no single way to deal with the impending sensation of harm.
For years, researchers have studied the stress spectrum and identified numerous behavioural changes. Most are relatively simple to understand such as heightened awareness, risk avoidance, and the fight or flight response.
Post-traumatic stress disorder (PTSD) is a scourge for anyone who suffers from it. The symptoms are heartbreaking – nightmares, flashbacks, poor sleep quality, irritability, and a lack of concentration. Some will feel disconnected from reality as they perceive being trapped in a mental cage from which they cannot break free.
In the playground, a popular game for kids of all ages is “Freeze.” The concept is rather simple. A leader tells the participants they are free to move around until everyone is told to freeze in place. Those who don’t suddenly stop are notified they are out and the game continues. It’s a great way to learn how to deal with environmental stimuli and also how to better control locomotor abilities. But most of all, it’s a great deal of fun.
Imagine repairing injured spinal cords or brains. Many may relegate this idea to the realms of science fiction yet researchers around the world continue to strive for this goal. They have developed and tested ways to rebuild the damage nervous system and bring back proper function. Some have even shown success in the lab.
Death is a normal part of the life cycle for cells. They form, grow, perform their expected duties and then, after a while, face a predictable fate. When the time comes, the cell undergoes a programmed process, known as apoptosis http://www.ncbi.nlm.nih.gov/books/NBK26873/ to break down many of the internal components and pave the way for the final end.
People usually find it easier to see things when they are big and bright, but there are occasionally exceptions. One example concerns moving objects: when they are small, we can identify their direction of motion easily. But this becomes much more difficult for larger objects. This phenomenon is known as spatial suppression http://www.nature.com/nature/journal/v424/n6946/full/nature01800.html.
Of all the neurodegenerative diseases, Alzheimer’s disease (AD) stands as the most common worldwide. While the onset is complex in nature, a hallmark sign of illness is the accumulation of a particular peptide in the brain, known as amyloid beta (Aβ) (http://www.jci.org/articles/view/25100). When present, the molecule can aggregate to form plaques and also interact with cells in the brain leading to altered signalling and function.