It has been one of the most discussed and intriguing topics -the quest to control neural circuitry as a precursor to decoding the operations of the human brain and manipulating its diseased state. Electrophysiology has created a gateway to control this circuitry with high precision. However, it is not practical to apply these techniques to living systems because these techniques are invasive and lack the spatial resolution necessary to properly address various neural cell components, cell assemblies or even tissues. Here we describe a new instrument that has the potential to replace the conventional patch clamping technique, the workhorse of neural physiology. A Digital Light Processing system from Texas Instruments and an Olympus IX71 inverted microscope were combined to achieve neuronal control at a subcellular spatial resolution. Accompanying these two technologies can be almost any light source, and for these experiments a pair of pulsed light sources that produced two pulse trains at different wavelengths tuned to activate or inactivate selectively the ChR2 and NpHR channels that were cloned to express light sensitive versions in neurons. Fura- 2 ratiometric fluorescent dye would be used to read-out calcium activity. The Pulsed light sources and a filter wheel are under computer control using a National Instruments digital control board and a CCD camera used to acquire real time cellular responses to the spatially controlled pulsed light channel activation would be controlled and synchronized using NI LabVIEW software. This will provide for a millisecond precision temporal control of neural circuitry. Thus this technology could provide researchers with an optical tool to control the neural circuitry both spatially and temporally with high precision.
[1]
Larry J. Hornbeck,et al.
Digital Light Processing for high-brightness high-resolution applications
,
1997,
Electronic Imaging.
[2]
Feng Zhang,et al.
Channelrhodopsin-2 and optical control of excitable cells
,
2006,
Nature Methods.
[3]
K. Deisseroth,et al.
Millisecond-timescale, genetically targeted optical control of neural activity
,
2005,
Nature Neuroscience.
[4]
H. Chiel,et al.
Fast noninvasive activation and inhibition of neural and network activity by vertebrate rhodopsin and green algae channelrhodopsin.
,
2005,
Proceedings of the National Academy of Sciences of the United States of America.
[5]
E. Isacoff,et al.
Light-activated ion channels for remote control of neuronal firing
,
2004,
Nature Neuroscience.
[6]
G. Feng,et al.
Next-Generation Optical Technologies for Illuminating Genetically Targeted Brain Circuits
,
2006,
The Journal of Neuroscience.
[7]
Karl Deisseroth,et al.
Excitation-Neurogenesis Coupling in Adult Neural Stem/Progenitor Cells
,
2004,
Neuron.
[8]
E. Bamberg,et al.
Channelrhodopsin-2, a directly light-gated cation-selective membrane channel
,
2003,
Proceedings of the National Academy of Sciences of the United States of America.