Hello everyone, I'm planning to perform viral vector injections into the cortex and hippocampus of C57BL/6 mice at postnatal day 21 (PND21), right after weaning. However, I’m facing some technical difficulties with properly securing the animals in the stereotaxic apparatus, likely due to their small size and fragility at this age.

I would really appreciate any advice or shared experience on: Specific protocols for stereotaxic surgery in PND21 (or younger) mice; Tips on how to adapt the stereotaxic frame for small animals (e.g., neonatal or custom ear bars/adaptors); Anesthesia and warming recommendations during the procedure; Strategies to stabilize the head and improve injection accuracy.

Any protocols, insights, or references would be extremely helpful.

Thank you in advance!