GRIN Lenses Support in Vivo Microendoscopy of the Brain
A recently published paper describes how gradient index (GRIN) lenses are used to perform microendoscopy on brain neurons. This paper is entitled, “High-throughput synapse-resolving two-photon fluorescence microendoscopy for deep-brain volumetric imaging in vivo.”
The Abstract of this paper states:
Optical imaging has become a powerful tool for studying brains in vivo. The opacity of adult brains makes microendoscopy, with an optical probe such as a gradient index (GRIN) lens embedded into brain tissue to provide optical relay, the method of choice for imaging neurons and neural activity in deeply buried brain structures. Incorporating a Bessel focus scanning module into two-photon fluorescence microendoscopy, we extended the excitation focus axially and improved its lateral resolution. Scanning the Bessel focus in 2D, we imaged volumes of neurons at high-throughput while resolving fine structures such as synaptic terminals. We applied this approach to the volumetric anatomical imaging of dendritic spines and axonal boutons in the mouse hippocampus, and functional imaging of GABAergic neurons in the mouse lateral hypothalamus in vivo.
The researchers used 10 commercially available GRIN lenses from GRINTECH in the experimental setup for this work.
About GRINTECH
GRINTECH is a leading manufacturer of GRadient INdex (GRIN) micro-optic lenses and lens systems. These miniaturized lenses provide extraordinarily good optical performance and flat optical surfaces. (See the Explanation of the physics of GRIN lenses.)
The optical power of GRIN lenses is achieved by a refractive index profile fabricated in glass by a non-toxic, silver-and-lithium-ion-exchange process. These unique rod and cylindrical micro-lenses have typical diameters from 200 µm to 2 mm.
The GRINTECH catalog includes:
- GRIN rods used for fiber and laser diode collimation and beam shaping
- Lenses and assemblies for clinical and industrial endoscopic applications
- Needle imaging assemblies and miniature high-NA objectives for in-vivo endomicroscopy and related accessories
These products are used for medical imaging and biophotonic technology, optical metrology, and sensor technology for applications such as brain imaging and endomicroscopy. In addition, GRINTECH develops, fabricates, and delivers high quality, reliable, custom-made modules and assemblies, tailored to the specific needs of customer applications. These assemblies and subassemblies are often inspired by or based on GRINTECH’s standard products.
To support industrial customers, GRINTECH’s team of optical designers and mechanical engineers design and produce more complex optical sensors, focusing or deflecting modules, imaging assemblies consisting of mechanical housings and mounts, optical fibers, prisms, beam splitters, laser diodes, etc., which are combined with GRIN and other lenses.
Customizations include: fiber type, length, buffer, connector type, prism size, stainless steel tube mounts, angled fiber end face, coatings, design wavelengths, spot or image working distance, spot size and numerical aperture, etc.
For more information or a quotation for GRINTECH products, contact IL Photonics.