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Table 2 Potential problems and troubleshooting

From: Craniula: A cranial window technique for prolonged imaging of brain surface vasculature with simultaneous adjacent intracerebral injection

Observation

Possible reason

Solution

Mouse is not breathing after being placed on stereotactic stage

Ear bars are too tight

Loosen the ear bars to allow air to flow freely through the trachea.

 

Possible respiratory failure

Gently release the mouse from the stage and administer oxygen inhalation using an inhaled anesthesia set up (by opening the oxygen flow meter without turning on the isoflurane vaporizer). Depending on the type of anesthesia equipment available, it might be necessary to purge the system before oxygen therapy can be administered. We encourage investigators to consult with a qualified veterinarian for more detailed advice

Vetbond™ on the foramen

Excess applied when window was being attached

Using a double-pronged tissue pick tool, gently scratch the Vetbond™ surrounding the cannula foramen. The Vetbond™ can be detached smoothly to clean out a space to place the cannula

Cannula misplacement

Cannula was not held in place for enough time to allow Vetbond™ to dry

Slight movement of the cannula when it is released from the forceps may indicate misplacement of the cannula. Remove the cannula from its position and clean it with sharp forceps to remove Vetbond™ from the foramen and surrounding area. Vetbond™ can be easily removed up to1-2 min following application. Care must be taken because any rough movement can permanently damage the craniula. Clean the foramen completely, taking care that the stainless steel part of the cannula is also free of Vetbond™. Once cleaned, the cannula can be reinserted

Unable to manage syringe containing Super Glue LocTite®

Thickness of the Super Glue LocTite®

When adding the second layer of Super Glue LocTite®, hold the needle hub firmly and push the plunger of the syringe slowly until a drop of glue forms on the needle bevel; then, gently apply the glue as described in corresponding section

Super Glue LocTite® on top of the cranial window

Mistake when adding the second layer of glue

Remove the glue with a scalpel by moving it towards the edges of the cover slip. Clean the edge of the scalpel after each stroke, thereby preventing glue from being placed back onto the cover slip

Dummy glued to the cannula

Vetbond™ in the groove of the cannula

When it is necessary to unscrew a glued dummy, it is possible that the cannula may detach from the skull, and possibly the cranial window will crack. Therefore, gentle and careful movement is essential. To unscrew a glued dummy, two straight mosquito hemostats can be used. Hold the bottom of the cannula with one hemostat. While holding the pedestal with the second hemostat, gently unscrew the dummy. This procedure must be done with the mouse under anesthesia