Aspects of reproduction and behavioral and vocal development in Senegal Bushbabies(Galago senegalensis)

AbstractVocal behavior can be dramatically changed by both neural circuit development and postnatal maturation of the body. During song learning in songbirds, both the song system and syringeal muscles are functionally changing, but it is unknown if maturation of sound generators within the syrinx contributes to vocal development. Here we densely sample the respiratory pressure control space of the zebra finch syrinx in vitro. We show that the syrinx produces sound very efficiently and that key acoustic parameters, minimal fundamental frequency, entropy and source level, do not change over development in both sexes. Thus, our data suggest that the observed acoustic changes in vocal development must be attributed to changes in the motor control pathway, from song system circuitry to muscle force, and not by material property changes in the avian analog of the vocal folds. We propose that in songbirds, muscle use and training driven by the sexually dimorphic song system are the crucial drivers that lead to sexual dimorphism of the syringeal skeleton and musculature. The size and properties of the instrument are thus not changing, while its player is.

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Traffic noise disrupts vocal development and suppresses immune function

Science Advances ◽

10.1126/sciadv.abe2405 ◽

2021 ◽

Vol 7 (20) ◽

pp. eabe2405

Author(s):

Henrik Brumm ◽

Wolfgang Goymann ◽

Sébastien Derégnaucourt ◽

Nicole Geberzahn ◽

Sue Anne Zollinger

Keyword(s):

Immune Function ◽

Noise Exposure ◽

Traffic Noise ◽

Vocal Learning ◽

Noise Pollution ◽

Experimental Models ◽

Speech Development ◽

Vocal Development ◽

Learning Impairments ◽

Cognitive Deficiencies

Noise pollution has been linked to learning and language deficits in children, but the causal mechanisms connecting noise to cognitive deficiencies remain unclear because experimental models are lacking. Here, we investigated the effects of noise on birdsong learning, the primary animal model for vocal learning and speech development in humans. We found that traffic noise exposure retarded vocal development and led to learning inaccuracies. In addition, noise suppressed immune function during the sensitive learning period, indicating that it is a potent stressor for birds, which is likely to compromise their cognitive functions. Our results provide important insights into the consequences of noise pollution and pave the way for future studies using birdsong as an experimental model for the investigation of noise-induced learning impairments.

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Expression of FoxP2 in the basal ganglia regulates vocal motor sequences in the adult songbird

Nature Communications ◽

10.1038/s41467-021-22918-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lei Xiao ◽

Devin P. Merullo ◽

Therese M. I. Koch ◽

Mou Cao ◽

Marissa Co ◽

...

Keyword(s):

Transcription Factor ◽

Basal Ganglia ◽

Dopamine Receptor ◽

Speech Disorders ◽

Receptor Expression ◽

Vocal Development ◽

Motor Actions

AbstractDisruption of the transcription factor FoxP2, which is enriched in the basal ganglia, impairs vocal development in humans and songbirds. The basal ganglia are important for the selection and sequencing of motor actions, but the circuit mechanisms governing accurate sequencing of learned vocalizations are unknown. Here, we show that expression of FoxP2 in the basal ganglia is vital for the fluent initiation and termination of birdsong, as well as the maintenance of song syllable sequencing in adulthood. Knockdown of FoxP2 imbalances dopamine receptor expression across striatal direct-like and indirect-like pathways, suggesting a role of dopaminergic signaling in regulating vocal motor sequencing. Confirming this prediction, we show that phasic dopamine activation, and not inhibition, during singing drives repetition of song syllables, thus also impairing fluent initiation and termination of birdsong. These findings demonstrate discrete circuit origins for the dysfluent repetition of vocal elements in songbirds, with implications for speech disorders.

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