TITLE: Essential surgeries for the electrophysiological recording from a behaving non-human primate brain 2 (Craniotomy)
AUTHORS: Daisuke Kase, Witold J Lipski, Devin R Harsch, Robert S Turner

[DESCRIPTION]
Outlined below are the steps to complete a craniotomy in an existing recording chamber placed on a cranial implant. This procedure can be done concurrently with the implant surgery (not recommended), or can take place upon recovery from the implant surgery.



[STEPS]
SECTION: Preparation in the prep room on the day of surgery
1. Sedate the animal.

SECTION: Preparation in the prep room on the day of surgery
2. Intubate the animal, start the gas anesthesia, and bring it to the surgical suite.
 

SECTION: Procedure in the surgical suite
3. Secure the animal’s head on the stereotaxic frame.
SECTION: Procedure in the surgical suite
4. Open the recording chamber.
SECTION: Procedure in the surgical suite
5. Clean the surface of the implants (chamber, head fixation post, dental acrylic, etc.) with Betadine and ethanol.
SECTION: Procedure in the surgical suite
6. Scrub in for the surgery. Wash hands (5 min per hand) and don a surgical gown and sterile gloves.
SECTION: Procedure in the surgical suite
7. Cover the animal’s whole body with a sterile drape.
SECTION: Procedure in the surgical suite
8. Put a sterile drill bit in the pin vise, and expose the drill bit about 3-4 mm from the pin vise.

 

SECTION: Procedure in the surgical suite
9. Slowly drill the first hole in the chamber with a pin vise until the pin vice touches the skull. The drill should not pierce the skull if the length is appropriately adjusted.

 

SECTION: Procedure in the surgical suite
10. Extend the drill bit a small amount, approximately 0.5 mm, then return to the hole that you drilled.
SECTION: Procedure in the surgical suite
11. Deepen the hole.

 

SECTION: Procedure in the surgical suite
12. Move to the next step if the skull is pierced and you can see the surface of the dura (it will look like a fascia of a piece of chicken). If the skull has not been pierced yet, return to Step 10.
SECTION: Procedure in the surgical suite
13. Make many holes to draw a circle of holes in the recording chamber.
SECTION: Procedure in the surgical suite
14. Remove the bone between holes with the bone rongeur.

 

SECTION: Procedure in the surgical suite
15. If bones between all holes are entirely removed, there should be a circle-shaped bone in the middle of the recording chamber.
SECTION: Procedure in the surgical suite
16. Raise the circle-shaped bone with tweezers and/or excavator spoon slowly and carefully.

 

SECTION: Procedure in the surgical suite
17. Remove the circle-shaped bone with tweezers carefully.
SECTION: Procedure in the surgical suite
18. Expand the hole with the bone punches.

 

SECTION: Procedure in the surgical suite
19. Scrape the sharp edge of the skull with the excavator spoon.

 

SECTION: Procedure in the surgical suite
20. Rinse the small pieces of bone from the chamber with saline.
SECTION: Procedure in the surgical suite
21. Measure the distance from the top edge of the chamber to the surface of the dura in multiple locations inside the chamber (ex. most medial, lateral, anterior, posterior corners, and center of the chamber).
SECTION: Procedure in the surgical suite
22. Place the chamber's cap onto the chamber and secure it.

SECTION: Procedure in the surgical suite
23. Stop the gas anesthesia, remove the intubation when the animal starts showing the reflex
Then, return the animal to the home cage.