Table 1.

Behavioral Phenotyping Assays

Behavioral Assay	Brief Description	Relevance to Autism Spectrum Disorders and Schizophrenia
6–12 Months of Age
Mother preference a	Following weaning, each infant was tested for 4 days to evaluate one aspect of mother-infant attachment, the infant’s preference for its own mother versus another familiar adult female (12 2-minute trials/subject).	Measures of attachment serve as control parameters for species-typical development and response to separation (48).
Postweaning solo Observations b	At approximately 10 months of age, the animals were observed alone in a large, unfamiliar cage for two 5-minute focal samples on 2 separate days to screen for abnormal behaviors such as motor stereotypies or self-directed behaviors.	Solo observations are conducted to screen for a wide array of stereotyped behaviors produced by rhesus monkeys (49,53,58).
12–18 Months of Age
Juvenile Y-maze	At approximately 18 months of age, animals were given visual access to a novel conspecific in one arm of a Y-maze test apparatus. Each animal was tested for six 2-minute trials on 2 separate days, meeting an opposite-sex conspecific on the first day and a same-sex conspecific on the second day.	Initial social assays with novel conspecifics were carried out using the Y-maze testing apparatus and later followed with the three-chambered social approach assay described below.
Juvenile solo Observationsb	At approximately 22 months of age, the animals were observed alone in a large, unfamiliar cage for two 5-minute focal samples on 2 separate days to screen for abnormal behaviors such as motor stereotypies or self-directed behaviors.	Solo observations are conducted to screen for a wide array of stereotyped behaviors produced by rhesus monkeys (49,53,58).
Juvenile social approachc	At approximately 24 months of age, social interactions with a novel conspecific were evaluated using a modified version of the mouse three-chambered social approach assay (20 minutes/subject).	The high-throughput social approach assay used in mouse models (54) paired with the fine-grained focal observations utilized in our nonhuman primate studies (47,48) provide a screen for sociability as indexed by the amount of time spent in a chamber with a constrained, novel conspecific.

ASD, autism spectrum disorders; SZ, schizophrenia.

^aAssays used to control for changes in physical development, reflexes, fear response development, maternal attachment, and activity levels that are not directly related to the core features of ASD and SZ.

^bBehavioral assays targeting repetitive behaviors and restricted interests.

^cBehavioral assays targeting social and communication domains.