Table 1.
Ethogram of Home Cage Observation Parameters
| Long Interaction: Two mice engage in directed social behaviors for at least 10 seconds |
| Investigative Behaviors |
| Anogenital Sniff: Subject mouse sniffs the anogenital region of the partner |
| Nose-to-Nose Sniff: Subject sniffs the head and snout region of the partner |
| Body Sniff: Subject sniffs any other area of the body of the partner |
| Follow: Subject follows the partner around the cage without any fast, sudden or run movements |
| Affiliative behaviors |
| Huddle: Lying flat or standing still, with eyes closed or open, while maintaining close physical contact with the partner. |
| Allogrooming: one mouse grooms the other mouse on any part of the body |
| Push under: Subject pushes underneath the partner’s anterior body area and rests in that position |
| Crawl over: Subject traverses the partner’s body by crawling over the back from one side to the other |
| Crawl under: Subject traverses the partner’s body by crawling under from one side to the other |
| Push past: Subject pushes between the partner and the cage wall |
| Aggressive behaviors |
| Attack: a rushing and leaping approach carried on over the back of the partner, often accompanied by biting attempts |
| Chase: Subject pursues a fleeing partner |
| Aggressive grooming: Subject persistently allogrooms the partner, accompanied by vigorous pulling of the back fur and nipping at the skin of the partner mostly around the nape of the neck; and holding the other mouse down with forepaws |
| Food competition: gross movements directed at the head or snout of a partner with a food item |
| Overtake: One mouse takes over the physical location of another mouse |
| Defensive behavior |
| Submissive upright posture: Subject stands on its hinds legs with head pulled back and body rigid |
| Flee: rapid movements to the opposite side of the cage in response to attacks |