2 Photon Random Access Mesoscope
About the innovation
Researchers at HHMI Janelia Research Campus have designed and built a 2-photon random access mesoscope (2p-RAM) that provides rapid access for imaging anywhere within a large tissue volume.
Cellular imaging can link activity in populations of neurons with behavior. But individual neurons are small, around 10μm diameter. Most microscopes with subcellular resolution have small fields-of-view and therefore cannot image neurons in multiple brain areas at the same time. Most large field-of-view microscopes do not resolve single cells, especially in the axial dimension.
The patent-pending 2p-RAM addresses these problems with technological advancements in remote focusing, correction of field curvature, and fast lateral and axial scanning. The complete 2p-RAM allows high-resolution imaging anywhere within a volume spanning multiple brain areas (∅ 5 mm x 1 mm cylinder) and resolution is near diffraction limited (lateral, 0.66 μm, axial 4.09 μm at the center; excitation wavelength = 970 nm; numerical aperture = 0.6) over a large range of excitation wavelengths. A fast three-dimensional scanning system allows efficient sampling of neural activity in arbitrary regions of interest across the entire imaging volume.
The 2p-RAM was made public and training offered to attendees at a Janelia 2p-RAM workshop in August 2016, where researchers learned to make and use the first 13 instruments outside of Janelia. The instrument is now available for purchase at Thorlabs, Inc. (see link to right), and the plans are available via Research License for individual academic use (see License Request to right).
Field of view (FOV) diameter: 5.0 mm
Imaging volume depth: 1mm
Excitation numerical aperture (NA): 0.6
Collection numerical aperture (NA): 1.0
Excitation wavelengths: 900 nm-1070 nm
Various custom components have been designed for use with the 2P-RAM, including head plates and a tilt stage. The original tilt stage is a motorized positioner intended for use with an air-suspended ball treadmill, which can be somewhat complex and expensive. An alternative is a rigid floor for the test subject with a single degree of freedom for adjustment. The design is compatible with the head plates also offered here.
Published U.S. Patent US 10,295,811 B2
- Commercially available from Thorlabs, Inc.
- Documentation may be licensed for non-profit research by emailing firstname.lastname@example.org.
- To learn more about the instrument, please view our documentation guidelines.
- Additional Free Mouse Headplate available here.
- Additional Goniometer/Positioner available here.
- Additional rigid-floor tilt stage available here.
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