Targeted Drug Delivery in a Mouse Model via Cisterna Magna Injection

Begin with an anesthetized mouse expressing a fluorescent marker gene, and secured in a stereotactic frame.

The head is tilted downward for easier access to the cisterna magna, the cerebrospinal fluid or CSF-filled space between the cerebellum and the brainstem.

Apply eye ointment, shave the neck, and sterilize.

Make a midline incision to expose the membrane covering the cisterna magna.

Retract the tissues with a separator to access the cisterna magna.

Take a microsyringe filled with an inducer drug and fitted with a bent needle.

Insert the needle and puncture the membrane to reach the cisterna magna.

Inject the drug slowly for uniform dispersion within the CSF.

The drug enters the brain surface cells and triggers the expression of the marker gene, producing red fluorescent proteins.

CSF flow prevents drug diffusion into deeper brain regions.

Fluorescence imaging confirms selective labeling of surface cells, demonstrating a targeted drug delivery to CSF-exposed regions.

Anesthetize the animal in the isoflurane chamber.

Then adjust the mouse head holder so that the mouthpiece is approximately at a 30 degree angle from the surface of the surgical table and fix the animal's head onto the holder.