Exploring the Zebra Finch Taeniopygia guttata as a Novel Animal Model for the Speech–Language Deficit of Fragile X Syndrome

Abstract

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and presents with markedly atypical speech-language, likely due to impaired vocal learning. Although current models have been useful for studies of some aspects of FXS, zebra finch is the only tractable lab model for vocal learning. The neural circuits for vocal learning in the zebra finch have clear relationships to the pathways in the human brain that may be affected in FXS. Further, finch vocal learning may be quantified using software designed specifically for this purpose. Knockdown of the zebra finch FMR1 gene may ultimately enable novel tests of therapies that are modality-specific, using drugs or even social strategies, to ameliorate deficits in vocal development and function. In this chapter, we describe the utility of the zebra finch model and present a hypothesis for the role of FMRP in the developing neural circuitry for vocalization.

Embryological staging of the Zebra Finch,Taeniopygia guttata

“…In recent years, Zebra Finches ( Taeniopygia guttata ) have become the predominant laboratory model species for songbird studies and have been used to address questions in a wide array of fields, including behavior (Maney and Goodson, ; Rosa et al, ), memory and learning (Moorman et al, ; Mayer et al, ), reproduction (Seguin and Forstmeier, ), aging (Austad, ; Heidinger et al, ), toxicology (Eng et al, ), neuroanatomy (Vargha‐Khadem et al, ), and plasticity and evolution (Chen et al, ; Keary and Bischof, ; Pytte et al, ). Notably, similarities in the mechanisms of song learning in the Zebra Finch and speech learning in humans make this bird a preeminent model system for studying the development of speech (Jarvis, ; Bottjer and To, ; Moorman et al, ; Walton et al, ; Winograd and Ceman, ). Zebra Finches are easily kept in captivity and breed rapidly and prolifically, thus providing a ready supply of study subjects.…”

FoxP2 isoforms delineate spatiotemporal transcriptional networks for vocal learning in the zebra finch

“…FMR1 encodes an RNA-binding protein and therefore its levels could have a profound effect on a number of targets in the network ( Ascano et al, 2012 ). FMR1 protein is expressed throughout the zebra finch song control circuit primarily in neurons, and birdsong has been suggested as an interesting model in which to study the gene’s function ( Winograd and Ceman, 2012 ; Winograd et al, 2008 ). Here, we observed a correlative link between FMR1 expression and how well the animal copied its tutor’s song, a novel association that could be reasonably hypothesized given the speech and language phenotype associated with FMR1 deficiency in humans.…”

The Known Unknowns: Missing Pieces in in vivo Models of Fragile X Syndrome

“…Mechanisms unknown [42], [43] Potential model to study the mechanisms behind speech and language pathology.…”