This video demonstrates the intracranial injection of short-chain fatty acids (SCFAs) in a freely moving mouse to study their effects on brain-mediated behavior. An injector cannula is inserted into a guide cannula implanted in the mouse brain. After recovery, the mouse acclimates in a novel cage. SCFAs are then administered, and locomotor behavior is recorded.
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Method Article
Intracranial Injection of Gut-Derived Microbial Metabolites in a Mouse Model
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August 7th, 2025
In This Article
Abstract
Protocol
All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. Preparation for the experimental animal
- Obtain 6-8-week-old wild-type C57BL/6JNarl male mice from a vendor.
- House the mice in a standard mouse cage with standard mouse chow and sterilized water ad libitum.
NOTE: The housing conditions for the Laboratory Animal Center are 22 ± 1 °C temperature, 55% ± 10% humidity, and a 13 h/11 h light/dark cycle.
2. Stereotaxic surgery
- Prepare and sterilize the stereota....
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Results
Figure 1: Implantation of the commercial guide cannula in mice. (A) The representative image of a commercial guide.......
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Materials
| Name | Company | Catalog Number | Comments |
|---|---|---|---|
| Material | |||
| Advil Liqui-Gels Solubilized Ibuprofen A2:D41 | Pfizer | n/a | |
| Bottle Top Vacuum Filter, 500 mL, 0.22 μm, PES, Sterile | NEST | 121921LA01 | |
| CaCl₂ | Sigma-Aldrich | C1016 | ACSF: 0.14 g/L |
| Chlorhexidine scrub 2% | Phoenix | NDC 57319-611-09 | |
| Chlorhexidine solution | Phoenix | NDC 57319-599-09 | |
| Commercial dummy | RWD Life Science | 62004 | Single_OD 0.20 mm/ M3.5/G = 0.5 mm |
| Commercial guide cannul | RWD Life Science | 62104 | Single_OD 0.41 mm-27G/ M3.5/C = 2.5 mm |
| Commercial injector | RWD Life Science | 62204 | Single_OD 0.21 mm-33G/ Mates with M3.5/C = 3.5 mm/G = 0.5 mm |
| D-(+)-Glucose | Sigma-Aldrich | G8270 | ACSF: 0.61 g/L |
| Dental acrylic | HYGENIC | n/a | |
| Fixing screws | RWD Life Science | 62521 | |
| Horse serum | ThermoFisher Scientific | 16050130 | |
| Insulin syringes | BBraun | XG-LBB-9151133S-1BX | 1 mL |
| Isoflurane | Panion & BF biotech | DG-4900-250D | |
| KCl | Sigma-Aldrich | P3911 | ACSF: 0.19 g/L |
| Ketoprofen | Swiss Pharmaceutical | n/a | |
| Lidocaine | AstraZeneca | n/a | |
| Low melting point agarose | Invitrogen | 16520 | |
| MgCl₂ | Sigma-Aldrich | M8266 | ACSF: 0.19 g/L |
| Microscope slides | ThermoFisher Scientific | 4951PLUS-001E | |
| Mineral oil light, white NF | Macron Fine Chemicals | MA-6358-04 | |
| NaCl | Sigma-Aldrich | S9888 | ACSF: 7.46 g/L |
| NaH₂PO₄ | Sigma-Aldrich | S8282 | ACSF: 0.18 g/L |
| NaHCO₃ | Sigma-Aldrich | S5761 | ACSF: 1.76 g/L |
| n-butyl cyanoacrylate adhesive (tissue adhesive glue) | 3M | 1469SB | 3M Vetbond |
| Neural tracer | Santa Cruz | SC-358883 | FluoroGold |
| Paraformaldehyde | Sigma-Aldrich | P6148 | |
| Polyethylene tube | RWD Life Science | 62329 | OD 1.50, I.D 0.50 mm and OD 1.09, I.D 0.38 mm |
| Puralube Vet (eye) Ointment | Dechra | 12920060 | |
| Sodium acetate | Sigma-Aldrich | S2889 | SCFAs: 13.5 mM |
| Sodium azide | Sigma-Aldrich | S2002 | |
| Sodium butyrate | Sigma-Aldrich | B5887 | SCFAs: 8 mM |
| Sodium propionate | Sigma-Aldrich | P1880 | SCFAs: 5.18 mM |
| Stainless guide cannula | Chun Ta stainless steel enterprise CO., LTD. | n/a | OD 0.63 mm; Local vendor |
| Stainless injector | Chun Ta stainless steel enterprise CO., LTD. | n/a | OD 0.3 mm; dummy is made from injector; local vendor |
| Superglue | Krazy Glue | KG94548R | |
| Triton X-100 | Merck | 1.08603.1000 | |
| Equipment | |||
| Cannula holder | RWD Life Science | B485-68217 | |
| Ceiling camera | FOSCAM | R2 | |
| Digital stereotaxic instruments | Stoelting | 51730D | |
| Dissecting microscope | INNOVIEW | SEM-HT/TW | |
| Glass Bead Sterilizer | RWD Life Science | RS1501 | |
| Heating pad | Stoelting | 53800M | |
| Micro Dissecting Forceps | ROBOZ | RS-5136 | Serrated, Slight Curve; Extra Delicate; 0.5mm Tip Width; 4" Length |
| Micro Dissecting Scissors | ROBOZ | RS-5918 | 4.5" Angled Sharp |
| Microinjection controller | World Precision Instruments (WPI) | MICRO2T | SMARTouch Controller |
| Microinjection syringe pump | World Precision Instruments (WPI) | UMP3T-1 | UltraMicroPump3 |
| Microliter syringe | Hamilton | 80014 | 10 µL |
| Optical Fiber Cold Light with double Fiber | Step | LGY-150 | Local vendor |
| Pet trimmer | WAHL | 09962-2018 | |
| Software | |||
| Animal behavior video tracking software | Noldus | EthoVision | Version: 15.0.1416 |
