News & Events

HEPL / KIPAC Seminar

Friday February 7, 2014

Keith Mathieson

Institute of Photonics
University of Strathclyde, Scotland, UK

Micron-scale LED Probes for In Vivo Spatiotemporal Optogenetic Activation of Neural Circuits

Abstract: Many interesting regions of the brain lie deep below the surface making it challenging to deliver light in a spatially precise fashion needed in some optogenetic studies. Adaptive optics, waveguides and fibres are possible solutions, but suffer from drawbacks such as limited light penetration and scalability issues.

Our solution is to microfabricate cellular-scale LEDs on a minimally invasive probe allowing the delivery of light to deep areas of the brain with high spatiotemporal accuracy. These probes can be narrow (80 mm) and thin (50 mm). Each LED can be as small as 10 mm in diameter and provide an irradiance up to ~500mW/mm2 at the surface.

We have studied the light output of these devices, the volume of tissue illuminated and the thermal characteristics of the probes. We show that the microLED devices can operate at pulse widths and frequencies relevant to optogenetic studies without increasing the temperature of nearby neurons by more than 0.5oC. The probes have been tested during in vivo experiments and were shown to drive spiking activity in ChR2-expressing neurons in the neocortex of transgenic mice.

Time: 3:00 – 3:45pm

Location: Physics/Astrophysics Bldg., Kistler Conference Room 102/103 (Map)

(Light refreshments available 2:45pm; Presentation begins3:00pm)

Open to All