Table S1.

Definition of social behavior in the social interaction test

Social behavior	Definition and detected criteria
Proximity	Two rats stay together, with their inter distance < 60 mm or <100 mm.
Approach	The approaching rat moves towards the other rat, with the angle < 45° and at the speed > 30 mm/s and the other rat moves at the speed < 100 mm/s. They travels at least 30 mm and for 2.0 sec continuously, with the distance between the 2 rats to be < 200 mm.
Leave	One rat leaves the other rat first, with the angle > 100° and at the speed > 30 mm/s. They travels at least 30 mm for 0.5 sec, with the distance between the 2 rats to be < 200 mm.
Social contact	Two rats stay together, with their inter distance < 20 mm.
Active social contact	Inter distance needs to be < 20 mm. One rat moves at the speed > 40 mm/s, with the ratio of the “movement” of the active rat vs. the passive rat to be greater than 2.0.
Passive social contact	The “movement” of the passive rat in active social contact.
Follow	One rat follows the other rat continuously at least for 0.5 sec, with the angle between their direction < 90°, the angle between the direction of the following rat and the line from him/her to the leaving rat < 30°, and the angle between the direction of the leaving rat and the line from him/her to the following rat > 100°. Their distance needs to be < 300 mm. Both rats need to move at least 5 mm, and the following rat needs to travel at least 30 mm.
Sniff	The distance between the nose of the sniffing rat and the body of the other rat needs to be < 30 mm, and the rat sniffs continuously at least for 0.27 sec.
Mount	Two-thirds of the head/body of 1 rat needs to ride on top of the other rat at least for 0.6s, with joint shape change of two rats.