Stereotaxic Cisterna Magna Approach for Therapeutic Delivery in a Mouse Model

Samenvatting

Source: Joshi, K., et al. Stereotaxic Surgical Approach to Microinject the Caudal Brainstem and Upper Cervical Spinal Cord via the Cisterna Magna in Mice. J. Vis. Exp. (2022)

This video demonstrates the cisterna magna stereotaxic approach for targeted delivery to the brainstem and upper spinal cord. By accessing the cerebrospinal fluid-filled cisterna magna, this approach enables precise injections into areas that are difficult to reach using standard stereotaxic methods.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Opening of the cisternal membrane

1. Use the angled Dumont forceps to grab the dura, which extends from the occipital bone to the atlas. Grab the dura near the occipital bone and use the spring scissors to make a small opening (~0.5 to 1.5 mm) in the dura.
   NOTE: At this rostral location, the space between the brainstem and the overlying dura is widest, providing ample room for safe manipulation of the dura.
2. Use the spring scissors to lift the dura and open the dura further. The size of the window depends on the target.
   NOTE: A larger window will be needed when making multiple longitudinal injections or bilateral injections; a small window will be sufficient when making single unilateral or midline injections.
3. Once the dura is opened, drain excess cerebrospinal fluid with a sterile cue tip.

2. Identification of landmarks and zero point

1. View the dorsal surface of the brainstem with detailed landmarks through the open dura. The obex, the point where the central canal opens into the IV ventricle, is the standard anterior-posterior and mediolateral zero point.

3. Injection of the target

1. Lower the pipette or syringe to the target using the stereotaxic arm and inject solution as for standard stereotaxic approaches. Leave in place for 1-5 min after injection to avoid a needle track when using volumes between 3-50 nL. Then, lift the pipette or syringe using the stereotaxic arm.
2. Repeat step 3.1. for multiple targets.

Materialen

Lijst van materialen gebruikt in dit artikel

Naam	Bedrijf	Catalogusnummer	Opmerkingen
Angled forceps, Dumont 5/45	FST	11251-35	Only to grab dura
Spring scissors, Vannas 2.5mm with accompanying box	FST	15002-08	Scissors only to open dura, box to elevate body
Stereotactic micromanipulator	Kopf	1760-61	Attached to electrode holder to adjust position based on co-ordinates
Stereotactic 'U' frame assembly and intracellular base plate	Kopf	1730-B, 1711	Frame for surgery
Sterile cotton tipped applicators	Puritan	25-806 10WC	Absorbing blood from surgical field