Calibration

The easiest method is to head-fix the mouse and adjust the position of the mirror and the angle of the cannula while monitoring video images using the head-mounted camera. If the mirror holder is not tight enough (i.e. the mirror is slowly moving due to gravity) it is possible to add a very thin layer of super glue around the cannula to increase friction. This allows the mirror to be adjusted but it will stay in the right position. Once the mirror has been adjusted such that the camera shows the desired field of view, carefully take off the camera holder (without touching the mirror), and secure the mirror holder using strong epoxy (e.g., Araldite Steel). Do not glue the mirror holder while the camera system is on the head of the mouse! The LED angle may also need to be adjusted. It is also possible to calibrate the camera in a freely moving mouse, e.g., by restraining the mouse by hand, but this requires experience and is not recommended for those new to the camera system. Another option is to briefly anaesthetize the animal for adjusting the mirror.