Identification of a Spinal Circuit for Light

In this paper, the researchers mapped out the neural circuitry and found that the key to integrating sensory information with the necessary corresponding motor function is a group of sensory neurons on the spinal cord that connect with the RORα neurons that bridge to the brain’s motor region. Together, it serves as a “mini-brain” that facilitates balance under difficult circumstances.

"We think these neurons are responsible for combining all of this information to tell the feet how to move," lead author Steeve Bourane added. "If you stand on a slippery surface for a long time, you'll notice your calf muscles get stiff, but you may not have noticed you were using them. Your body is on autopilot, constantly making subtle corrections while freeing you to attend to other higher-level tasks.”

Disabling this circuitry in mice revealed that while they could still walk under normal conditions, when the terrain got more difficult, they were incapable of making the small foot adjustments in order to maintain balance and walk smoothly. Getting a better understanding of this pathway and other mechanisms the brain uses to process sensory information could lead to improved therapies for those affected by spinal cord disease or trauma.

http://www.cell.com/cell/abstract/S0092-8674(15)00012-4 http://www.cell.com/cell/abstract/S0092-8674(15)00012-4

World Health Organisation Worried Regarding Huge Rise in Hearing Loss

Being told that you are at risk of hearing loss might not make for easy listening but according to the World Health Organization, around 1.1 billion teenagers and young adults face this risk due to exposure to unsafe levels of sound.

World Health Organisation (WHO), recommend restricting the use of personal audio devices to less than one hour per day. Exposure to high levels of recreational noise from personal audio devices and loud entertainment venues are to blame for this risk, the WHO state, in a report released in the run up to International Ear Care Day on March 3rd.

"As they go about their daily lives doing what they enjoy, more and more young people are placing themselves at risk of hearing loss http://www.medicalnewstoday.com/articles/249285.php," states Dr. Etienne Krug, WHO director for the Department for Management of Noncommunicable Diseases, Disability, Violence and Injury Prevention.

"They should be aware that once you lose your hearing, it won't come back. Taking simple preventive actions will allow people to continue to enjoy themselves without putting their hearing at risk."

Across the world, around 360 million people - over 5% of the world's population - have moderate to profound hearing loss. A wide range of factors can lead to hearing loss, including genetic conditions, specific infectious diseases, drug use, aging and environmental noise. WHO estimate that around half of all instances of hearing loss are avoidable.

Individuals are said to have hearing loss if they are unable to hear as well as someone with normal hearing - hearing thresholds of 25 dB or better in both ears. Disabling hearing loss is defined as having hearing loss greater than 40 dB in the better hearing ear for adults and 30 dB for children.

WHO analyzed a number of studies from middle- and high-income countries that indicated around half of people aged 12-35 years are exposed to unsafe levels of sound from personal audio devices, including smartphones. Around 40% of this age group are also exposed to potentially damaging levels of sound in venues such as night clubs, bars and at sporting events.

Unsafe levels of sound are described as exposure to sound that is 85 dB or over for 8 hours, or 100 dB or over for just 15 minutes.

WHO recommend 'simple preventive actions' The amount of damage that is done depends on multiple factors - the duration of exposure to the sound, how intense or loud the sound is and how frequently exposure to unsafe levels of sound occurs. Temporary hearing loss or tinnitus http://www.medicalnewstoday.com/articles/156286.php can occur due to loud sounds, but too much exposure can result in more serious and permanent damage.

A number of measures are recommended by WHO to protect people from avoidable hearing damage. Employers and governments have a role to play in protecting teenagers and young adults from hearing loss.

Venues where noise levels can typically reach levels of 100 dB such as concert venues should reduce the duration of time these levels occur for or reduce the volume altogether. WHO state that the highest permissible level of noise exposure in the workplace is 85 dB for up to a maximum of 8 hours per day.

The provision of protective ear plugs and "chill out" rooms can also make a difference to patrons of these venues. WHO also call for governments to develop and enforce legislation concerning recreational noise levels, as well as raising awareness of the risks surrounding hearing loss through public information campaigns.

Teenagers and young adults can do many things to help themselves too; measures as simple as keeping the volume of personal audio devices down to safe levels. Wearing ear plugs when visiting an environment with loud sound levels is important, as is limiting the amount of time spent engaging in activities with potentially unsafe sound levels.

Hearing loss can have a significant impact on everyday life, with WHO reporting that it can lead to loneliness, isolation and frustration. By taking a few simple precautions, thousands of teenagers and young adults can protect themselves and avoid the risk of it ever affecting their lives.

Previously, Medical News Today reported on a mouse study suggesting that noise-induced hearing loss could be prevented with a vitamin supplement http://www.medicalnewstoday.com/articles/286408.php that protects the nerves that stimulate the cochlea.

Written by James McIntosh http://www.medicalnewstoday.com/authors/james-mcintosh