20-003931- Purchase Description.pdf

Version 11-30-2016-1 FAR Part 11—Describing Agency Needs

PURCHASE DESCRIPTION

1. Statement of Need and Purpose:

The Unit on Functional Neural Circuits (UFNC) focuses specific circuits and neuronal types that enable internally-generated brain activity to interact with sensation, with emphasis on different types of cortical GABAergic (gamma-aminobutyric acid) neurons.

Our project aims to delineate the functional connectivity among related brain areas, to identify the behavioral relevance of these circuits, to understand the computations these circuits perform, and to uncover their developmental specificity and plasticity. One of the aims is identifying different cortical subnetworks during different behavioral conditions.

Our study will greatly benefit from using a multiphoton microscope to image and manipulate specific populations of neurons using 3D spatial light modulator (SLM) photostimulation from awake animals. This will facilitate our research to achieve more comprehensive understanding of specific neural circuits and the relevant behavior.

2. Background Information and Objective:

One of the aims in the Unit on Functional Neural Circuits is to identify functionally distinct cortical subnetworks during different behavioral conditions. In order to do conduct the experiments, we heavily rely on a two-photon microscope system which allow us to monitor large population of neurons with high spatiotemporal resolution while manipulating specific population of neurons.

3. Generic Name of Product: Multi-photon micrscopy system with 3D spatial light modulator (SLM) photostimulation

4. Purchase Description:

Ultima 2P Plus; multi-photon micrscopy system with 3D spatial light modulator (SLM) photostimulation, quantity 1

5. Salient characteristics

1. Scanning Field-of-View: The scan head realizes a new optical design optimized for extended scanning field-of-view in both galvo mode and resonant mode. The system maintains PSF within 1 axial PSF across entire field at scan zoom 1x.

Overscan allows for scan zoom 0.8x for 1.4mm x 1.4mm field of view with Nikon 16x 0.8 objective. With an overscan Field Number of 28.3mm the 2P Plus has the largest scanning field of view of any commercial system.

2. 3D Volume imaging with ETL: The microscope includes a motorized Z focus; it also includes an electrically tunable lens (ETL) in the resonant scan path. The ETL provides high-speed dynamic positioning of the focal plane for Z-stacks. It is also decoupled from the photoactivation scan path, enabling simultaneous imaging and photoactivation from different Z-locations.

a. 480um range

b. 15ms step response, can be driven faster depending with tradeoff in ringing

c. Magnification corrected at each limit of range to 1.1x

d. Spherical aberration corrected with custom aspheric lens

e. Axial PSF measured 5 – 5.5um throughout range

3. • Close Proximity Detectors: it must offer up to four detectors that are in close proximity to the objective and move in unison with the objective. The short and fixed path length between the collection lens and objective allows for more efficient collection of scattered photons and 14° angle of collection from back aperture of the objective.

4. 2” Collection optics: it uses 2” collection optics from the objective to the detectors to ensure that the diverging photons end up hitting the photo cathode of the detectors instead of getting lost along the way.

5. Synchronization via BNC connection for timing of experimental apparatus is to be standard.

6. Rotating Nosepiece: Single axis rotating nosepiece that swivels 90 degrees on either side of its normal position. This allows users to image regions that are on the back or the side of the head such as auditory cortex. This feature does not require any re-orientation of the scan head or realignment of laser transfer optics, nor does it affect the optical relationship between the objective and PMT photo cathodes.

7. Resonant Scanner “add-on”: The resonant scanner is a true add-on, meaning it is relayed onto the standard 6mm imaging galvos. This architecture allows for either traditional raster scanning in galvo mode (adjustable dwell time, line scans, ROIs, etc) or high-speed scanning in resonant mode, selectable via drop-down in software for seamless switching. Resonant ROIs have increased SNR as the resonant scanner can be re-centered in the field of view with the x-galvo.

8. Optogenetics: It includes a secondary galvo path for stimulation using a separate laser. This pathway is independent from the imaging pathway, enabling simultaneous imaging and stimulation through the Mark Points software module.

Allows for synchronization with analog voltage input/output and imaging acquisition.

9. 3D SLM: Perform simultaneous multi-point optical stimulation/activation in the secondary galvo pathway. Utilizes a custom Spatial Light Modulator for dynamic control of the wavefront in Fourier space to manipulate the number of spots created and their position in 3D space. Coupling into the galvo path allows for use of diffraction-limited spots that can be spiraled rapidly with the galvos, maintaining photon density for reliable activation and covering larger areas (e.g.

cell bodies) with the spirals. This enables SLM module to take advantage of existing uncaging, raster, point, and spiral activation protocols that have been vetted by the scientific community.

a. 512 x 512 pixels

b. 7ms response time using reflective LCD surface

c. Numerical Aperture selectable via lens sets, 0.6 or 0.8

d. Field of View 150 x 150 x 150um with 0.8 NA or 300 x 300 x 300um with

0.6NA

e. Wavelength range 500 to 1100nm

f. Optional Dielectric mirror for increased reflectivity with tradeoff in wavelength range and rolloff

g. Fully integrated into Prairie View software for GUI-based Mark Points experiments in 3D

h. Can be used to generate traditional holographic patterns on the sample

10. Moving Microscope: Translation along X and Y axes, up to 1.5”, in addition to the standard Z axis 1.25”. This allows use of simple, non-motorized, experiment-specific stages for in vivo experiments where the specimen is held stationary while the scope is moved around (such as a head-fixed mouse running on a ball or a customized tread mill). This also enables Atlas Imaging, a software feature for visualizing a montage and picking out ROIs from a large sample area.

11. More than 1000 frames per second imaging: Resonant scanner enables high speed scanning (30fps at 512 x 512 resolutions at full field of view). This is particularly useful for Calcium imaging. Use of ROIs (regions of interest) with resonant scanner provides even higher frame rates limited only by the number of lines in the ROI. These ROIs can have any number of pixels along a line leading to better SNR, and better sample viability. Since the ROIs are not limited to 32 or more lines, frame rates greater than 1000 fps can be achieved; for instance 790fps for 512 x 16 ROI or 1319fps for 512 x 8 ROI.

12. High Efficiency GaAsP detectors with shutters: The detectors are cost-effectively upgraded to high sensitivity GaAsP detectors hand-selected for QE > 45%.

These detectors have about twice the QE of multi alkali detectors. High-speed shutters are integrated into the detector mounts to protect the PMTs from exposure to any Photoactivation light or ambient light when not in use for imaging.

13. Timing and Recombination Unit for timing synchronized beams, application for multi-color two-photon fluorescence microscopy

14. Fixed dispersion compensation for 1045 nm beam, 15000 fs^2

15. Tiling software for Whole Brain Imaging: Software provides a highly intuitive user interface to capture high resolution images of large samples (whole brains in 3D).

The preview mode allows users to setup the acquisition, and the software combined with high precision stages collects the images in “tiles” to construct the whole image in 3D. This feature is enabled by the motorized XYZ microscope and is fully functional on sample stages with static position.

16. User login based software configuration: The software supports multiple users and saves their configurations within their logins. It also allows users to save multiple configurations (relating to different experiments) for fast and easy re-loading of correct experimental parameters.

17. Real Time Data Analysis and Feedback: The software makes the data available to an external program so that the data can be analyzed in real time if required.

For instance, a third party program such as Matlab can request image data from the software, analyze the image and send commands back to the software to move the stage to bring the cell of interest back to the middle of field of view. All of this can be done in real time.

18. Synchronization with ePhys: The software provides accurate timing information about scans using pixel clock, line clock, and frame clock signals (TTL). These signals can be used to trigger external devices. In addition, the software provides the ability to produce up to 8 analog outputs and record from up to 16 analog inputs synchronized with photo-stimulation experiments.

6. Quantity: Quantity 1, Ultima 2P Plus

7. Delivery Date: Requested delivery date is October 30, 2020

8. Period of Performance: for one year warray after installation (Covered by full system one-year, unlimited hours warranty)

9. Option(s): N/A