Light Beads Microscopy

The Volumetric Calcium Imaging 2-Photon Activity Microscope (vCAm) module introduces a significant advancement in neuroscience imaging. As an innovative implementation of Light Beads Microscopy (LBM) by MBF, it transforms conventional two-photon microscopes, allowing researchers to image complete neural volumes up to 0.5mm deep as quickly as it takes to image a single plane in traditional setups. This technology, originating from Dr. Alipasha Vaziri’s lab at Rockefeller University, marks a breakthrough in high-speed volumetric brain imaging.

LBM provides a solution to the challenges faced by current two-photon scanning techniques, particularly in handling image resolution, acquisition speed, and maintaining a favorable signal-to-noise ratio (SNR) during volumetric imaging. Brain tissue's light-scattering properties often complicate this balance. LBM optimizes spatiotemporal signal acquisition, operating at data rates determined by the lifetime of neural calcium indicators like GCaMP.

Key Benefits

• Enables acquisition of up to 30 planes in a volume ranging from approximately 300µm to 600µm.
• Matches the lifetime of GCaMP, using one excitation pulse per voxel to maximize signal-to-noise ratio per unit of power.
• Integrates with most two-photon microscopes when combined with the appropriate optics.
• Operates with femtosecond lasers having repetition frequencies from 4.5MHz to 5MHz.

LBM utilizes high-energy femtosecond laser pulses at a low repetition rate (approximately 4.5 MHz to 5 MHz) for highly temporally multiplexed acquisition of axial planes. This approach allows the capture of up to 30 planes within the same time frame that traditional microscopy requires for a single plane. Moreover, LBM enhances the SNR by applying a single excitation pulse per voxel.

The module supports a wavelength range of 900 to 1050 nm, with vertical input polarization, and an input beam size of 3 mm. Key dimensions are 675x500x120 mm, and it requires a 4.5 to 5 MHz laser frequency.

For those curious about the technical performance, at a 4.5 MHz laser frequency, the system can generate a maximum of 32 planes, 30 planes at 4.7 MHz, and 28 planes at 5 MHz, within a temporal window of 6.8ns for the demultiplexing channels.