Intracerebroventricular Injection in Mouse: An Ommaya Mediated Direct Drug Administration Method to Deliver Drugs to Cerebral Ventricles of Mouse Brain

Assemble the Murine Ommaya injection device using a 25G miniature injection port and a 1-millimeter spacer disc.

Use a cyanoacrylate sterile adhesive to ensure the penetration of approximately 2.5 millimeters of the metal cannula into the right cerebral hemisphere and prepare the skin according to sterile technique.

Make a small skin incision, followed by blunt dissection of the underlying subcutaneous tissues to expose the skull. Dry the skull using hydrogen peroxide-soaked cotton-tipped applicator sticks.

Drill a 0.9-millimeter burr hole in the skull, 0.5 millimeters posterior and 1.1 millimeters lateral of the bregma, to expose the dura mater.

Move the microdrill aside and gently score the bone immediately surrounding the burr hole. Affix an injection port to the skull using a cyanoacrylate sterile adhesive and insert it to a depth of approximately 2.5 millimeters.

Suture the incision using 4-0 non-absorbable nylon sutures in an interrupted stitch pattern or purse string suture. House post-surgery mice in individual cages for recovery.

To dose the mouse, access the Murine Ommaya using a port injection adapter and a Hamilton syringe. Using forceps, hold the top of the miniature injection port and gently insert the port injector adapter fully into the port's septum.

Once the injection is made, detach the Murine Ommaya from the port injection adapter with forceps.