optogenetics tagged posts

Image illustrating the concept of the sleep homeostat. Credit: Centre for Neural Circuits and Behaviour/ University of Oxford

Oxford University researchers have discovered what causes a switch to flip in our brains and wake us up. Sleep is governed by 2 systems – the circadian clock and the sleep homeostat. While the circadian clock is quite well understood, very little is known about the sleep homeostat. Professor Gero Miesenböck explained: ‘The circadian clock allows us to anticipate predictable changes in our environment that are caused by the Earth’s rotation. As such, it makes sure we do our sleeping when it hurts us least, but it doesn’t speak to the mystery of why we need to sleep in the first place.

‘That explanation will likely come from understanding the second controller – slee...

All-optical system for control of wave dynamics in biological media.

Team first to use optogenetics to control excitation waves in heart cells.
We depend on electrical waves to regulate the rhythm of our heartbeat. When those signals go awry, the result is a potentially fatal arrhythmia.
For heart patients there are currently 2 options to keep these waves in check: electrical devices (pacemakers or defibrillators) or drugs (eg beta blockers). However, these methods are relatively crude: they can stop or start waves but cannot provide fine control over the wave speed and direction

Dr Gil Bub, from Oxford University explained: ‘When there is scar tissue in the heart or fibrosis, this can cause part of the wave to slow down...

A breakthrough study shows that fat tissue is innervated and that direct stimulation of neurons in fat is sufficient to induce fat breakdown. These results set up the stage for developing novel anti-obesity therapies. Fat tissue constitutes 20 – 25% of human body weight being an energy store in the form of triglycerides. 20 yrs ago Jeffrey Friedman and colleagues identified the hormone leptin, which is produced by fat cells in amounts that are proportional to the amount of fat, and informs the brain about how much fat is available in the body. Leptin functions as an “adipostat” neuro-endocrine signal that preserves body’s fat mass in a relatively narrow range of variation...