PhD Project 7
Neurogenomics of vocal learning: decoding the functions of FoxPs in vocal perception and production learning
The discovery that the FOXP2 gene is implicated in speech and language provided the first molecular windows into this trait. One way to decipher the roles of genes like FOXP2 is through comparative research using songbirds - birds that acquire their songs by auditory-guided vocal learning. Using FoxP knockdown technology, we will assess functions of zebra finch FoxP genes for a novel subject - the perception, discrimination and processing of vocalizations, such as natural songs, along with strings of song elements organized according to artificial grammar algorithms. This promises unique insights into evolutionary precursors of linguistic function in non-speaking species.
This project uniquely brings together behavioural work and molecular genomics experiments. It not only involves collaboration inside, but also outside our consortium (Constance Scharff; Freie Universität Berlin) and combines expertise in neurogenomic techniques and behavioural test essays. Thus far, no study has examined the role of FoxP genes for vocal perceptual learning in any animal model. This may also provide a new window on their role in human speech and language processing, where the effects of these genes on vocal perception are hard to disentangle from other effects and not experimentally accessible.
Sample sizes were increased relative to those reported in 2015 resulting in reliable experimental data on FoxP1 knockdowns in HVC of adult female zebra finches. Compared to control individuals, the knockdown birds show decreased motivation to receive an auditory reward while neither general activity nor cognitive aspects seem to be affected. First RNA sequencing results and analyses of the dopaminergic system suggest a malfunction of the internal rewarding system caused by reduced amounts of FoxP1. A second batch of RNA samples is currently investigated to confirm these results.
In parallel, a pilot on FoxP1 knockdown in adult female CMM was tested on behavioural differences which served two purposes: as a successful additional control for the first knockdown group and an investigation of the auditory tasks of FoxP1 in CMM that do not seem to be involved in memory maintenance and discrimination learning in adult birds.
A first group of juvenile females just underwent knockdown of FoxP1 in HVC and awaits behavioural testing in order to investigate the role of FoxP1 during auditory development in the sensory phase of vocal learners.