Design and use method of deep brain imaging fixed base based on miniaturized microscopic system

Abstract

The invention discloses a design and use method of a deep brain imaging fixed base based on a miniaturized microscopic system, the main body of the base is a substrate with an opening in the center, the diameter of the opening is equivalent to that of a gradient refractive index lens commonly used by the miniaturized microscopic system, and the purpose is that the lens can penetrate through the base to reach a position near an observation part for imaging. The inner layer of the substrate is matched with the bottom of the miniaturized microscopic system in size and is used for fixing the miniaturized microscopic system. Rare earth magnets are embedded in the four corners of the substrate, have the same magnetic orientation and attract magnets fixed at the same position of the bottom of the microscope, so that the uniform level of the miniaturized microscopic system relative to the substrate during fixation is ensured, and the optimal imaging effect is realized. The base structure designed in the scheme realizes the fixation of the head miniaturized microscopic system for deep brain imaging under the condition of free movement of animals.

Description

Technical Field

[0001] Miniaturized microscopy is an effective method for imaging the brain of animals under free movement conditions, especially for imaging deep in the brain. For deep brain imaging, a relay lens needs to be placed in front of the objective lens, which places higher demands on the stability of the overall structure and the fixation of the microscope. Therefore, how to stably fix the entire miniaturized microscopic imaging system on the animal's head is a problem that must be solved to ensure the imaging process. Background Art

[0002] Deep imaging of the brain is crucial for many applications. Multiphoton microscopy can achieve this at limited depth and limited resolution. Multiphoton microscopy works similarly to scanning confocal microscopy, except that it exploits the phenomenon of multiphoton absorption to excite fluorescent markers. With longer wavelength (>780nm) excitation and an average excitation power of 1W, the maximum penetration depth can reach 600-800μm, which can be increased to 1mm when the laser is used with a regenerative amplifier to produce more powerful laser pulses. However, this comes at the expense of poor spatial resolution, as the diffraction limit is determined by the longer wavelength and scattering in the tissue. With three-photon microscopy, penetration depths of up to 1.2mm can be achieved. However, three-photon or multiphoton excitation is very inefficient, which requires sufficiently large excitation intensities due to low absorption cross sections, also leading to potential phototoxicity. In addition, many interesting biological features exist at depths greater than 1.2mm from the brain surface, such as the basal ganglia, hippocampus, and hypothalamus.

[0003] Miniaturized fluorescence microscopy is a deeper method than multiphoton imaging. In miniaturized fluorescence microscopy, a miniature optical probe is inserted into an area of ​​interest in the brain. The probe transmits light signals in and out of the area. The most common example is a fiber bundle. However, the fiber bundle diameter is often large, which may cause trauma to deep brain imaging. In addition, due to crosstalk between adjacent nuclei, it is difficult to ensure a resolution below ~3μm. Another method of miniaturized fluorescence microscopy imaging is to use a GRIN lens as an objective lens. The GRIN lens produces a spatially varying refractive index through controllable doping of glass. For deep brain imaging of miniaturized microscopy systems, a smaller diameter relay gradient refractive index lens (GRIN relay lens) is often coupled below the GRIN lens. This relay lens is inserted into the deep brain of the animal being tested and directs the signal into the GRINlens as the objective lens, realizing the imaging process of the deep brain of freely moving animals.

[0004] In addition, advances in surgical techniques have also enabled miniaturized microscopic imaging systems to avoid damage to brain tissue to the greatest extent when implanted below the skull; at the same time, miniaturized microscopic imaging systems are completely within the tolerance of animals due to their light weight and small size. Through reasonable design and the use of components of appropriate size, such as using gradient refractive index lenses instead of normal-sized lenses for imaging, designing and using small-sized glass slides, etc., and assembling them into a 3D-printed shell for fixed integration, a small-sized and low-mass head-mounted microscope can be obtained. Due to its small and light characteristics, this microscope can image the deep brain of mice without affecting their normal behavioral activities, thereby obtaining the most realistic and credible brain neural images.

[0005] In summary, the miniaturized microscopic imaging system can ensure that animals can image deep brain neurons under the premise of free will and free activities, such as pathological changes, recovery, and social behavior, and analyze the working status of neurons and the entire neural tissue. Due to its small size and high integration, the miniaturized microscopic system can complete the measurement work under special circumstances. Therefore, in life sciences and industrial testing, the miniaturized microscopic system is of great significance.

[0006] However, the miniaturized microscope system cannot be directly connected to the mouse head because of its complex structure and small size, which makes it difficult to fix. Even if it is barely fixed, the imaging effect will be affected by violent shaking. In addition, the deep brain probe has increased the requirements for fixation stability due to the increase in axial space. This requires a device that can ensure a stable connection with the mouse head to fix the miniaturized microscope system to assist in normal and stable imaging. Summary of the invention

[0007] A brief overview of the present invention is provided below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0008] In view of this, in order to overcome the above-mentioned technical problems, the present invention provides a design and use method of a deep brain imaging fixed base based on a miniaturized microscope system, which realizes a device that can firmly fix the miniaturized microscope system on the head of an experimental animal, thereby ensuring the smooth progress of the entire imaging process.

[0009] Solution 1: The present invention provides a design method for a deep brain imaging fixed base based on a miniaturized microscopic system, wherein the deep brain imaging fixed base of the miniaturized microscopic system comprises: a substrate, a rare earth magnet, a fixing screw 1, a fixing screw 2, a GRIN lens, and a GRIN relay lens;

[0010] Furthermore: there is a hole with a diameter of 2 mm in the center of the substrate, which is convenient for a GRIN lens with a diameter of 2 mm to pass through and thus form an image.

[0011] Furthermore: the substrate has a rectangular groove with a size of 10mm×6mm×5mm, a groove depth of 4mm and a wall thickness of 2mm.

[0012] Furthermore: the fixing screw 1 and the fixing screw 2 are both self-tapping screws with a diameter of 2 mm.

[0013] Furthermore: the magnets are all rare earth magnets with the same magnetic orientation, evenly distributed at the four corners of the substrate, and just coincide with the position of the magnets at the bottom of the designed miniaturized microscope system.

[0014] Further: when the substrate is fixed to the head of the test animal, it is necessary to scratch some marks on the bottom with a sharp object to make the bond between it and the glue more firm and tight.

[0015] Furthermore: the substrate is made of photosensitive resin using a 3D printer.

[0016] Solution 2: The present invention proposes a method for using a deep-brain imaging fixed base based on a miniaturized microscope system. This method is implemented based on the design method of a deep-brain imaging fixed base based on a miniaturized microscope system described in Solution 1. The method of use is divided into three parts, namely surgical implantation steps, fixation steps and microscope installation steps.

[0017] Surgical implantation steps:

[0018] After the craniotomy, the GRIN relaylens is first implanted at the target to be detected and fixed with ear-brain glue. Then the position of the GRIN lens is adjusted to make the image clear and visible. Then glue is used to keep the relative position of the two unchanged.

[0019] Fixing steps:

[0020] After craniotomy, place the baseplate in the appropriate position and use a sharp object to gently scrape the animal's skull and the bottom of the baseplate to make the connection with the glue tighter.

[0021] Microscope installation steps:

[0022] The miniaturized microscope system is gently placed on the substrate, and the rare earth magnet at the bottom of the system fits with the magnet with opposite magnetic properties at the bottom of the microscope, thereby ensuring the level of the microscope to avoid affecting the imaging effect. Then, the microscope is tightly fixed on the substrate by rotating the fixing screws 1 and 2.

[0023] Beneficial Effects

[0024] The present invention provides a solution for fixing a miniaturized microscope system during deep brain imaging experiments on freely moving mouse heads. Two screws on the base plate ensure that the microscope can be tightly fixed. In addition, four magnets are introduced on the base plate, which cooperate with four magnets on the microscope with the same position and opposite magnetic properties to ensure uniform and horizontal installation of the microscope, thereby ensuring the normal progress of the imaging process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a deep brain imaging fixed base based on a miniaturized microscope system of the present invention.

[0026] In the figure: 1 substrate, 2 rare earth magnet, 3 fixing screw 1, 4 fixing screw 2, 5 GRIN lens, 6 GRIN relaylens. DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present invention will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the disclosure of the present invention.

[0028] It is also necessary to explain here that, in order to avoid obscuring the present invention due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0029] Embodiment 1: As attached Figure 1 As shown, the present invention provides a design method for a deep brain imaging fixed base based on a miniaturized microscope system, which is used to solve the problem of fixing the miniaturized microscope system on the head of a freely moving mouse.

[0030] The deep brain imaging fixed base of the miniaturized microscopy system comprises: a base plate 1, a rare earth magnet 2, a fixing screw 13, a fixing screw 24, a GRIN lens 5 and a GRIN relay lens 6;

[0031] More specifically: the substrate 1 has a hole with a diameter of 2 mm in the center, which is convenient for a GRIN lens with a diameter of 2 mm to pass through and thus form an image.

[0032] More specifically: the substrate 1 has a rectangular groove with a size of 10 mm×6 mm×5 mm, a groove depth of 4 mm, and a wall thickness of 2 mm.

[0033] The fixing screws 13 and 24 are both self-tapping screws with a diameter of 2 mm.

[0034] More specifically: the magnets 2 are all rare earth magnets with the same magnetic orientation, evenly distributed at the four corners of the substrate, and just coincide with the position of the magnets at the bottom of the designed miniaturized microscope system.

[0035] More specifically: when the substrate 1 is fixed to the head of the test animal, it is necessary to scratch some marks on the bottom thereof with a sharp object to make the bonding between it and the glue more firm and tight.

[0036] More specifically: the substrate 1 is made of photosensitive resin using a 3D printer.

[0037] A method for using a deep brain imaging fixed base based on a miniaturized microscopic system, which is implemented based on the design method of the deep brain imaging fixed base based on a miniaturized microscopic system described in Example 1, and specifically comprises the following steps:

[0038] Surgical implantation steps:

[0039] After the craniotomy, the GRIN relay lens 6 is first implanted at the target to be detected and fixed with ear-brain glue. Then the position of the GRIN lens 5 is adjusted to make the image clear and visible. Then glue is used to keep the relative position of the two unchanged.

[0040] Fixing steps:

[0041] After the craniotomy, the base plate 1 is placed in a suitable position, and the animal skull and the bottom of the base plate are lightly scraped with a sharp object to make the connection with the glue more firm.

[0042] Microscope installation steps:

[0043] The miniaturized microscope system is gently placed on the substrate 1, and the rare earth magnet 2 at the bottom thereof fits with the magnet with opposite magnetic properties at the bottom of the microscope, thereby ensuring the level of the microscope to avoid affecting the imaging effect. The microscope is then tightly fixed on the substrate by rotating the fixing screws 13 and 24.

[0044] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted for facilitating understanding of the technical solution of the present invention, and are not used to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the core technical solution disclosed in the present invention, but the protection scope defined by the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A fixed base for deep brain imaging based on a miniaturized microscopic system, characterized in that: The deep brain imaging fixed base of the miniaturized microscope system comprises: a base plate (1), a rare earth magnet (2), a fixing screw 1 (3), a fixing screw 2 (4), a gradient refractive index lens (GRIN lens) (5) and a relay gradient refractive index lens (GRIN relay lens) (6).

2. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: The substrate (1) has a hole with a diameter of 2 mm in the center, which facilitates the passage of a GRIN lens with a diameter of 2 mm, thereby forming an image.

3. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: The base plate (1) has a rectangular groove with a size of 10 mm×6 mm×5 mm, a groove depth of 4 mm and a wall thickness of 2 mm.

4. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: The fixing screw 1 (3) and the fixing screw 2 (4) are both self-tapping screws with a diameter of 2 mm.

5. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: The magnets (2) are all rare earth magnets with the same magnetic orientation, and are evenly distributed at the four corners of the substrate, exactly coinciding with the position of the magnets at the bottom of the designed miniaturized microscope system.

6. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: When the base plate (1) is fixed to the head of the test animal, it is necessary to scratch some marks on the bottom of the base plate (1) with a sharp object to make the connection between the base plate (1) and the glue more firm and tight.

7. The deep brain imaging fixed base based on the miniaturized microscopic system according to claim 1, characterized in that: The substrate (1) is made of photosensitive resin using a 3D printer.

8. According to claim 1, the method for using the deep brain imaging fixed base based on the miniaturized microscopic system is divided into three parts, namely, a surgical implantation step, a fixation step, and a microscope installation step, characterized in that: Surgical implantation steps: After the craniotomy, the GRIN relay lens (6) is first implanted at the target site to be detected and fixed with ear-brain glue. The position of the GRIN lens (5) is then adjusted to make the image clearly visible. The relative position of the two is then maintained unchanged with glue. Fixing steps: Place the base plate (1) at a suitable position on the head, and use a sharp object to lightly scrape the animal's skull and the bottom of the base plate to make the connection with the glue more secure. Microscope installation steps: The miniaturized microscope system is gently placed on the base plate (1), and the rare earth magnet (2) at the bottom thereof is fitted with the magnet with opposite magnetic properties at the bottom of the microscope, thereby ensuring that the microscope is level so as not to affect the imaging effect. The microscope is then tightly fixed on the base plate by rotating the fixing screws 1 (3) and 2 (4).

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