Project: High Precision Spatial and Temporal control of neural circuitry using a semi-automated, multi-wavelength submicron system

Champion: Sandhya Mitnala

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 lacks the spatial resolution necessary to properly address various neural cell components, cell assemblies or even tissues. We have foreseen that the nanopatterning system has the capability to replace the conventional patch clamping technique, the workhorse of neural physiology. This system could be used to achieve neuronal control at a sub-cellular 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 for calcium activity read-out. The dimension of temporal control was added to the system using Labview software and a digital control board by National Instruments to synchronize and control the various components of the system. Thus this technology could provide researchers with an optical tool to control the neural circuitry both spatially and temporally with high precision.

Figure 1: ChR2 channels tagged to mCherry fluorescent dye

Figure 2: NpHR channels tagged to EYFP fluorescent dye