Mice were anesthetized with 1.5% isoflurane and placed in a stereotaxic frame.

Body temperature was maintained using a heating pad.

The skin was incised to expose the skull after asepsis and connective tissue was

removed.

To implant electroencephalogram (EEG) and electromyogram (EMG) recording

electrodes, two stainless steel screws were inserted into the skull 2.5 mm from

the midline and 3 mm posterior to the bregma, and two EMG electrodes were also

inserted into the neck muscles.

A reference screw for grounding was placed on top of the left cerebellum.

Insulated leads from the EEG and EMG electrodes were soldered to a pin header, which was

secured to the skull using dental cement.

After a minimum of 7 days of undisturbed post-surgery recovery, behavioral

experiments were carried out in home cages placed in sound-attenuating boxes.

EEG and EMG electrodes were connected to flexible recording cables via a

mini-connector.

Recordings started after 1-2 days of habituation and continued for 3-4 days on a 12-h

dark/12-h light cycle.

Mouse behavior was recorded using a video camera at 10 frames per second (fps), along

with EEG and EMG recordings.

The signals were recorded with a TDT RZ10x/PZ5-32 or LR10-SK1 system.