Abstract
BACKGROUND: Quantitative genetic analysis of basic mouse behaviors is a powerful tool to identify novel genetic phenotypes contributing to neurobehavioral disorders. Here, we analyzed genetic contributions to single-trial, long-term social and nonsocial recognition and subsequently studied the functional impact of an identified candidate gene on behavioral development.
METHODS: Genetic mapping of single-trial social recognition was performed in chromosome substitution strains, a sophisticated tool for detecting quantitative trait loci (QTL) of complex traits. Follow-up occurred by generating and testing knockout (KO) mice of a selected QTL candidate gene. Functional characterization of these mice was performed through behavioral and neurological assessments across developmental stages and analyses of gene expression and brain morphology.
RESULTS: Chromosome substitution strain 14 mapping studies revealed an overlapping QTL related to long-term social and object recognition harboring Pcdh9, a cell-adhesion gene previously associated with autism spectrum disorder. Specific long-term social and object recognition deficits were confirmed in homozygous (KO) Pcdh9-deficient mice, while heterozygous mice only showed long-term social recognition impairment. The recognition deficits in KO mice were not associated with alterations in perception, multi-trial discrimination learning, sociability, behavioral flexibility, or fear memory. Rather, KO mice showed additional impairments in sensorimotor development reflected by early touch-evoked biting, rotarod performance, and sensory gating deficits. This profile emerged with structural changes in deep layers of sensory cortices, where Pcdh9 is selectively expressed.
CONCLUSIONS: This behavior-to-gene study implicates Pcdh9 in cognitive functions required for long-term social and nonsocial recognition. This role is supported by the involvement of Pcdh9 in sensory cortex development and sensorimotor phenotypes.
Original language | English |
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Pages (from-to) | 485-495 |
Number of pages | 11 |
Journal | Biological Psychiatry |
Volume | 78 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1-Oct-2015 |
Externally published | Yes |
Keywords
- Associative learning
- Autism spectrum disorder
- Genetic mapping
- Information processing
- Pcdh9
- QTL
- Quantitative trait locus
- Recognition
- Sensory cortex
- Social cognition
- CHROMOSOME SUBSTITUTION STRAINS
- AUTISM SPECTRUM DISORDER
- CONDITIONED CONTEXTUAL FEAR
- NON-CLUSTERED PROTOCADHERIN
- DELTA-PROTOCADHERINS
- DISCRIMINATION PROCEDURE
- INTERMEDIATE PHENOTYPES
- PSYCHIATRIC-DISORDERS
- NERVOUS-SYSTEM
- ANIMAL-MODELS