The role of emotional brain processing during sleep in depression.

ACCESSIBLE SUMMARY: • Explores current research illuminating the physiological mechanisms contributing the relationship of sleep dysfunction and depression. • Investigates the crucial role of sleep in the affective modulation of brain functioning. • Describes the relationship between emotional brain processing during rapid eye movement and depression. • Points to the use of multi-therapeutic approaches for treatment with emphasis on positive behavioural imagery therapies. ABSTRACT: This review synthesizes some of the most current investigative research to illuminate the physiological mechanisms contributing to the relationship between sleep dysfunction and depression. Major depression has consistently been linked to sleep abnormalities and insomnia is a robust risk factor in the initiating and development of depression. Recent neurobiological findings indicate the crucial role of sleep in the affective modulation of brain functioning. Studies have demonstrated that sleep in major depression is characterized by a reduction in slow wave sleep, interruptions in sleep continuity, longer periods of rapid eye movement (REM) sleep including a shortening of REM latency (i.e. the time between sleep onset and the occurrence of the first REM period), as well as an increase in REM density. The failure of sleep dependant emotional brain processing in REM sleep that seems to occur in depression, support the development and fostering of clinical depression. How depression likely interplays with these sleep processes points to the use of multi-therapeutic approaches for treatment with emphasis on positive behavioural imagery therapies.

A nanoscale Ti∕GaAs metal-semiconductor hybrid sensor for room temperature light detection.

We report an individually addressable Ti∕GaAs metal-semiconductor hybrid optical nanosensor with positive photoresistance and a sensitivity that increases as the device dimensions shrink. The underlying physics relates to the crossover from ballistic to diffusive transport of the photoinduced carriers and the geometric enhancement of the effect associated with a Schottky-barrier-coupled parallel metal shunt layer. For a 250 nm device under 633 nm illumination we observe a specific detectivity of D(*)=5.06×10(11) cm √Hz∕W with a dynamic response of 40 dB.