1 research outputs found
Outan: An On-Head System for Driving micro-LED Arrays Implanted in Freely Moving Mice
In the intact brain, neural activity can be recorded using sensing electrodes
and manipulated using light stimulation. Silicon probes with integrated
electrodes and micro-LEDs enable the detection and control of neural activity
using a single implanted device. Miniaturized solutions for recordings from
small freely moving animals are commercially available, but stimulation is
driven by large, stationary current sources. We designed and fabricated a
current source chip and integrated it into a headstage PCB that weighs 1.37 g.
The proposed system provides 10-bit resolution current control for 32 channels,
driving micro-LEDs with up to 4.6 V and sourcing up to 0.9 mA at a refresh rate
of 5 kHz per channel. When calibrated against a micro-LED probe, the system
allows linear control of light output power, up to 10 micro-W per micro-LED. To
demonstrate the capabilities of the system, synthetic sequences of neural
spiking activity were produced by driving multiple micro-LEDs implanted in the
hippocampal CA1 area of a freely moving mouse. The high spatial, temporal, and
amplitude resolution of the system provides a rich variety of stimulation
patterns. Combined with commercially available sampling headstages, the system
provides an easy to use back-end, fully utilizing the bi-directional potential
of integrated opto-electronic arrays.Comment: 11 pages, 9 figure