vocal experimentation in the juvenile songbird requires a basal ganglia circuit直言不讳的实验在少年songbird需要基底神经节电路.pdfVIP

Open access, freely available online PLoS BIOLOGY Vocal Experimentation in the Juvenile Songbird Requires a Basal Ganglia Circuit ¨ 1,2 1 1* Bence P. Olveczky , Aaron S. Andalman , Michale S. Fee 1 McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America, 2 Harvard Society of Fellows, Harvard University, Cambridge, Massachusetts, United States of America Songbirds learn their songs by trial-and-error experimentation, producing highly variable vocal output as juveniles. By comparing their own sounds to the song of a tutor, young songbirds gradually converge to a stable song that can be a remarkably good copy of the tutor song. Here we show that vocal variability in the learning songbird is induced by a basal-ganglia-related circuit, the output of which projects to the motor pathway via the lateral magnocellular nucleus of the nidopallium (LMAN). We found that pharmacological inactivation of LMAN dramatically reduced acoustic and sequence variability in the songs of juvenile zebra finches, doing so in a rapid and reversible manner. In addition, recordings from LMAN neurons projecting to the motor pathway revealed highly variable spiking activity across song renditions, showing that LMAN may act as a source of variability. Lastly, pharmacological blockade of synaptic inputs from LMAN to its target premotor area also reduced song variability. Our results establish that, in the juvenile songbird, the exploratory motor behavior required to learn a complex motor sequence is dependent on a dedicated neural circuit homologous to cortico-basal ganglia circuits in mammals. ¨ Citation: Olveczky BP, Andalman AS, Fee MS (2005)