Editor's Summary 5 March 2009 Just a song at sunrise Behavioural studies show that sleep plays a role in learning, and birdsong is a well established model system for the study of learning. It has been proposed that forebrain premotor neuron activity in sleeping adult zebra finches reflects daytime singing episodes. Now Sylvan Shank and Daniel Margoliash demonstrate a surprising role for sleep in establishing the organization of the songbird's brain at the time the bird first starts to learn to sing. In juvenile zebra finches yet to master their song, exposure to an adult 'tutor' song produced profound changes in the premotor neuronal activity during the subsequent sleep session. These changes in night-time activity are echoed in tutor-song-induced changes in singing the next day.
Nature 458, 73-77 (5 March 2009) | doi:10.1038/nature07615 http://www.nature.com/nature/journal/v458/n7234/full/nature07615.html Letter Sleep and sensorimotor integration during early vocal learning in a songbird Sylvan S. Shank & Daniel Margoliash Abstract Behavioural studies widely implicate sleep in memory consolidation in the learning of a broad range of behaviours. During sleep, brain regions are reactivated, and specific patterns of neural activity are replayed, consistent with patterns observed in previous waking behaviour. Birdsong learning is a paradigmatic model system for skill learning. Song development in juvenile zebra finches (Taeniopygia guttata) is characterized by sleep-dependent circadian fluctuations in singing behaviour, with immediate post-sleep deterioration in song structure followed by recovery later in the day. In sleeping adult birds, spontaneous bursting activity of forebrain premotor neurons in the robust nucleus of the arcopallium (RA) carries information about daytime singing. Here we show that, in juvenile zebra finches, playback during the day of an adult 'tutor' song induced profound and tutor-song-specific changes in bursting activity of RA neurons during the following night of sleep. The nigh! t-time neuronal changes preceded tutor-song-induced changes in singing, first observed the following day. Interruption of auditory feedback greatly reduced sleep bursting and prevented the tutor-song-specific neuronal remodelling. Thus, night-time neuronal activity is shaped by the interaction of the song model (sensory template) and auditory feedback, with changes in night-time activity preceding the onset of practice associated with vocal learning. We hypothesize that night-time bursting induces adaptive changes in premotor networks during sleep as part of vocal learning. By this hypothesis, adaptive changes driven by replay of sensory information at night and by evaluation of sensory feedback during the day interact to produce the complex circadian patterns seen early in vocal development. Research Highlights Nature 458, 10 (5 March 2009) | doi:10.1038/458010d; Zoology: Nightingale serenade Proc. R. Soc. B doi:10.1098/rspb.2008.1726 (2009) http://rspb.royalsocietypublishing.org/content/early/2009/02/27/rspb.2008.1726.abstract Male nightingales that sing during the night are serenading females, whereas those that sing at dawn are letting other males know that the territory is occupied, report Tobias Roth of the University of Basel in Switzerland and his co-workers. The researchers caught ten female nightingales (Luscinia megarhynchos) and moved them 70 km to a site in the Rhine Valley in France where the team has studied nightingales since 1994. Radio transmitters glued on the backs of the incomers revealed that unpaired females fly around at night visiting several males, at a time when bachelor males are singing more frequently than paired males. All males sing vociferously during the dawn chorus, however. Enjoy! Xiao XIAO, Jianqiang, Ph.D. Research Associate Psychology Department Rutgers University 152 Frelinghuysen Road Piscataway, NJ 08854 _________________________________________________________________ Show them the way! Add maps and directions to your party invites. http://www.microsoft.com/windows/windowslive/products/events.aspx
