Learning-Related Neuronal Activation in the Zebra Finch Song System Nucleus HVC in Response to the Bird’s Own Song

Johan J. Bolhuis,Ardie M. den Boer-Visser,Nienke J. Terpstra,Matthijs A. Zandbergen,Sharon M. H. Gobes,David S. Vicario

doi:10.1371/journal.pone.0041556

Johan J. Bolhuis, Ardie M. den Boer-Visser + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0041556

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Journal: PloS one	Publication Date: Jul 25, 2012
Citations: 66	License type: CC BY 4.0

Affiliation: Utrecht University, Leiden University, Wellesley College

Abstract

Like many other songbird species, male zebra finches learn their song from a tutor early in life. Song learning in birds has strong parallels with speech acquisition in human infants at both the behavioral and neural levels. Forebrain nuclei in the ‘song system’ are important for the sensorimotor acquisition and production of song, while caudomedial pallial brain regions outside the song system are thought to contain the neural substrate of tutor song memory. Here, we exposed three groups of adult zebra finch males to either tutor song, to their own song, or to novel conspecific song. Expression of the immediate early gene protein product Zenk was measured in the song system nuclei HVC, robust nucleus of the arcopallium (RA) and Area X. There were no significant differences in overall Zenk expression between the three groups. However, Zenk expression in the HVC was significantly positively correlated with the strength of song learning only in the group that was exposed to the bird’s own song, not in the other two groups. These results suggest that the song system nucleus HVC may contain a neural representation of a memory of the bird’s own song. Such a representation may be formed during juvenile song learning and guide the bird’s vocal output.

Highlights

Birdsong learning is a prominent model system for the study of the neural mechanisms of learning and memory [1,2,3,4,5,6,7]
We found that similarity with the tutor song correlated significantly with immediate early gene (IEG) expression in the song system nucleus HVC in males that were exposed to bird’s own song (BOS), and not in males that were exposed to tutor song or to novel song
There were no significant differences in overall neuronal activation between adult zebra finches exposed to tutor song, bird’s own song (BOS) or novel conspecific song in any of the song system nuclei (HVC, RA and Area X) that we sampled

Summary

Introduction

Birdsong learning is a prominent model system for the study of the neural mechanisms of learning and memory [1,2,3,4,5,6,7]. There are behavioral similarities between the way that songbirds learn to sing their songs and human infants acquire speech and language, that are absent in non-human primates who do not seem to have a capacity for vocal imitation [8,9,10] Songbirds such as zebra finches (Taeniopygia guttata) learn their songs from an adult conspecific, or ‘tutor’, during a sensitive period early in life [11,12]. Song learning occurs in two partially overlapping phases: a memorization phase during which the bird forms an auditory memory of the tutor song, and a sensorimotor phase when the animal starts vocalizing and eventually develops a ‘crystallized’ song that may resemble that of its tutor In both human infants and juvenile songbirds there is a sensitive period for learning early in life, and a transitional phase called ‘babbling’ and ‘subsong’, respectively. Brain regions outside the song system that are involved in perception and recognition of song include the caudomedial nidopallium (NCM) and the caudomedial mesopallium (CMM) [4,5,19,20,21,22,23,24,25,26,27,28,29] (Fig. 1A)

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