Download - Rapp OptoElectronic

Application Note
Rapp OptoElectronic UGA-40
User:
Dr Ole Paulsen & Michael Kohl
The Neuronal Oscillations Group
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
http://noggin.dpag.ox.ac.uk
System:
•UGA-40 scanning system
•DL-473 blue diode laser
Application:
Light stimulation in acute brain slices of Channelrhodopsin-2 (Boyden et al., 2005) transfected mice.
Channelrhodopsin-2 is a cation channel derived from algae that will open with millisecond precision upon
illumination with blue light (excitation maximum around 470 nm) and depolarise neuronal membranes.
This can be used to selectively activate neurons and neuronal fibres expressing this protein replacing the
need for extracellular electric stimulation.
In a pilot study, we used this channel in combination with the Rapp OptoElectronic UGA-40 system to map
excitatory inputs from the CA3 area into the CA1 area of the hippocampus in acute brain slices. We
injected a virus vector containing a cre-dependent Channelrhodopsin-2-YFP construct into the CA3 area
of CamKIIa-cre mice. CamKIIa positive cells (excitatory) in the CA3 area and their projections expressed
the Channelrhodopsin-2 after 10 days incubation. Panel A shows 23 illumination locations in the CA1 area,
set using the sequence stimulation function of the UGA-40 and an extracellular recording electrode placed
in the stratus radiatum. Panel B shows an overlay of extracellular field potentials in response to 5 ms
illumination at each point.
The UGA-40 in combination with an appropriate light source is ideal for functional connectivity studies of
neuronal populations using Channelrhodopsins.
A
B
References:
Boyden et al. Millisecond-timescale, genetically targeted optical control of neural activity. Nat Neurosci
(2005) vol. 8 (9) pp. 1263-8.