Role of Autism Susceptibility Gene, CNTNAP2, in Neural Circuitry for Vocal Communication
Abstract
Variants of the contactin associated protein-like 2 (Cntnap2) gene are risk factors for language-related disorders including autism spectrum disorder, specific language impairment, and stuttering. Songbirds are useful models for study of human speech disorders due to their shared capacity for vocal learning, which relies on similar cortico-basal ganglia circuitry and genetic factors. We investigated Cntnap2 protein expression in the brain of the zebra finch, a songbird species in which males, but not females, learn their courtship songs. We hypothesized that Cntnap2 has overlapping functions in vocal learning species, and expected to find protein expression in song-related areas of the zebra finch brain. We found that Cntnap2 protein is enriched in several song control regions relative to surrounding tissues, particularly within the adult male, but not female, robust nucleus of the arcopallium (RA), a cortical song control region analogous to human layer 5 primary motor cortex. The onset of this sexually dimorphic expression coincides with the onset of sensorimotor learning in developing males. Enrichment in male RA appears due to expression in projection neurons within the nucleus, as well as to additional expression in nerve terminals of cortical projections to RA from the lateral magnocellular nucleus of the nidopallium. Cntnap2 protein expression in zebra finch brain supports the hypothesis that this molecule affects neural connectivity critical for vocal learning across taxonomic classes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2013
- Accession Number
- ADA604001
Entities
People
- Stephanie A. White
Organizations
- University of California, Los Angeles