title: Maturation-dependent control of vocal temporal plasticity in a songbird.
abstract: Birdsong is a unique model to address learning mechanisms of the timing control of sequential behaviors, with characteristic temporal structures consisting of serial sequences of brief vocal elements (syllables) and silent intervals (gaps). Understanding the neural mechanisms for plasticity of such sequential behavior should be aided by characterization of its developmental changes. Here, we assessed the level of acute vocal plasticity between young and adult Bengalese finches, and also quantified developmental change in variability of temporal structure. Acute plasticity was tested by delivering aversive noise bursts contingent on duration of a target gap, such that birds could avoid the noise by modifying their song. We found that temporal variability of song features decreased with birds' maturation. Noise-avoidance experiments demonstrated that maximal changes of gap durations were larger in young that in adult birds. After these young birds matured, the maximal change decreased to a similar level as adults. The variability of these target gaps also decreased as the birds matured. Such parallel changes suggest that the level of acute temporal plasticity could be predicted from ongoing temporal variability. Further, we found that young birds gradually began to stop their song at the target gap and restart from the introductory part of song, whereas adults did not. According to a synaptic chain model for timing sequence generation in premotor nuclei, adult learning would be interpreted as adaptive changes in conduction delays between chain-to-chain connections, whereas the learning of young birds could mainly depend on changes of the connections. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 995-1006, 2017.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Ryosuke O
authors.identifier: 0000-0002-4766-4504
authors.initials: RO
authors.lastname: Tachibana
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Takahasi
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Neal A
authors.initials: NA
authors.lastname: Hessler
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.|Cognition and Behavior Joint Laboratory, RIKEN Brain Science Institute, Saitama, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Okanoya
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001921:Brain / Q000254:growth & development / Q000502:physiology; D056344:Executive Function / Q000502:physiology*; D046369:Finches / Q000254:growth & development* / Q000502:physiology; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology; D009622:Noise; D013018:Sound Spectrography; D013997:Time Factors; D014828:Vocalization, Animal / Q000502:physiology*
keywords: auditory feedback; gap stretching; plasticity; temporal variability