Source: Guo, J. et al., Canalostomy as a Surgical Approach to Local Drug Delivery into the Inner Ears of Adult and Neonatal Mice. J. Vis. Exp. (2018)
This video showcases canalostomy, a procedure that allows local drug delivery into the inner ear of a mouse through the semicircular canal with minimal damage to hearing and vestibular function. This method enables the inoculation of viral vectors, pharmaceuticals, and small molecules into the mouse's inner ear.
All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. Device Preparations
2. Canalostomy in Adult Mice
Figure 1: Device preparation. (A) The polyimide tubing (i) and the polyethylene tubing (ii) are sealed to make an injection cannula (iii). (B) The cannula is connected to a 10-µL micro-syringe with a 30 G needle and then installed on a pump. Arrow indicates the cannula tip. (C) Injection reagent and normal saline are separated by an air gap.
Figure 2: Canalostomy in an adult mouse. (A) A post-auricular incision (arrow). (B) Muscles covering the temporal bone are exposed. If we define the root of the pinna (bold dot) as the origin and the plane parallel to the calvarium as 3/9 o'clock, the posterior semicircular canal (PSC) and lateral semicircular canal (LSC) are generally located in the region between 2 and 3 o'clock (pentagram), ~3 mm from the origin. Inset: lower-magnification image of the orientation. The dotted line indicates the calvarium plane. (C) The PSC and LSC are exposed (dotted lines). Inset: The LSC is at an approximately 30° angle from the plane parallel to the calvarium, and the PSC is vertical to the LSC. (D) A small hole is made in the PSC. (E) The tip of the cannula is inserted into the PSC, and the reagent is injected. (F) The hole is sealed with a small piece of muscle. Scale bar in A is 5 mm, that in B is 1 mm (B for B-F), that in the inset to B is 1 cm, and that in the inset to C is 5 mm.
The authors have nothing to disclose.
Polymide Tubing | A-M Systems | 823400 | |
Polyethylene Tubing | Scientific Commodities Inc. | BB31695-PE/1 | |
10μl Microsyringe | Hamilton Company | 80001 | |
Xylazine HCL | Sigma-Aldrich Co. Llc. | X-1251 | |
Operating Miroscope | Carl Zeiss Optical LLC. | Pico | |
Micro Forceps | Dumont Dumostar | 10576 | |
Fast-green Dye | Sigma-Aldrich Co. Llc. | F7252 | |
AAV8-GFP | BioMiao Biological Technology Co. Ltd (Beijing, China) | 20161101 | Titer: 2×10e12 vg/mL |
Streptomycin Sulfate | Sigma-Aldrich Co. Llc. | S9137 | |
Microinjection Pump | Stoelting Co. | 789100S | |
Electric Pad | Pet Fun | 11072931136 | |
1 cc Syringe | Mishawa Medical Industries Ltd. (Shanghai, China) | 2011-3151258 | |
Ketamine HCL | Gutian Pharmaceutical Co., Ltd. (Fujian, China) | H35020148 | |
Electric Animal Clipper | Codos Electrical Appliances Co., Ltd. (Guangdong, China) | CP-8000 | |
Cotton Pellet | Yatai Healthcare Ltd. (Henan, China) | Yu-2008-1640081 | |
Suture | Shanghai Pudong Jinhuan Medical Products Co., Ltd. (Shanghai, China) | Hu-2013-2650207 | |
Eye Ointment | Beijing Shuangji Pharmaceutical Ltd. (Beijng China) | H11021270 |
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