Figure 3. Autonomous training and initial head-fixation of facility-housed mice.

(a) Five mice were trained within a conventional animal facility with minimal daily investigator contact. Twelve days after installation of transcranial windows, mice were started on water bottle training within a dummy cage for 7 days (no electronics, as in Supplementary Fig. 2); after this, they were switched to the head-fixing cage to receive ‘entrance' and ‘contact-based' rewards for 5 days over which time they increased entries into the fixation tube and made successful contact with the mechanism that would normally engage head-fixation. The power to solenoids was turned on and multiple head-fixes were observed within 30 min of system full function. Entries and head-fixes are plotted for the first month that this cage was functioning. (b) Plots showing individual entries and head-fixes (red dashes) with diurnal variation being apparent. The beginning of the plot reflects the initiation of training for three of five mice in cage GU. There were two episodes of ‘prolonged confinement', the mouse can be seen exiting the device but re-entering several more times within minutes (indicated in figure).