Sleep and memory consolidation during vocal learning in songbirds
Sensory and Behavioural Biology
Final Report Abstract
After decades of study, the functions of sleep are still obscure. Among many hypotheses, one of the most promising suggests a role for sleep in the consolidation of recent memories. Vocal learning in songbirds is one of the few innate learning models that can be used to study the effects of sleep on memory. As a juvenile bird learns to sing, it must undergo a complex memory task that involves the formation of auditory memories, sequences of motor output, and associative higher-order representations of learned vocalizations. By understanding how vocal learning is related to brain activity during sleep, we may gain a better understanding of the connection between sleep, learning, and the consolidation of recently acquired memories. The main objective of this project (“Sleep and memory consolidation during vocal learning in songbirds”) was to investigate brain activity during sleep in birds, and more specifically, the role of sleep in memory formation. In order to investigate the brain activity during sleep in actively learning juveniles, we recorded sleep-related signals from the brains of juvenile songbirds. We found that subtle differences existed in the structure of juvenile sleep compared to adult sleep. For example, we found that juveniles underwent fewer transitions between sleep stages compared to adults, and that the low-frequency component of the sleep signal was significantly larger in the juvenile group compared to adults. However, there was no significant difference between adults and juveniles in the amount of time spent in different sleep stages. During sleep, we also recorded large amplitude events (sharp wave-ripples, SWR) which had several attributes (e.g., their spatial distribution and their role in generating sequences of neural activation during sleep) that likely facilitate memory consolidation in the avian brain. These findings point toward a mechanism of memory consolidation in the avian brain. Finally, we recorded sleeping brain activity from male juvenile birds actively engaged in song learning. We plan to correlate brain activity during slow wave sleep and REM sleep with awake vocal performance and examine the trajectory of learning by comparing the juvenile bird’s first songs renditions to its final crystallized songs. Altogether, these experiments have provided greater insight into the vital functions of sleep and its role in memory consolidation.
Publications
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Hippocampal-like network dynamics underlie avian sharp wave-ripples. Cold Spring Harbor Laboratory.
Yeganegi, Hamed; Luksch, Harald & Ondracek, Janie M.
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Sleep and memory consolidation in songbird” NEURO DoWo 30th conference, 28-31 August, 2019, Würzburg, Germany.
Hamed Yeganegi
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“Avian sharp wave-ripples reveal link to ancestral sleep circuits.” Neuroscience Abstract; Program No. 331.17. 2019. San Diego, CA, USA.
Janie Ondracek
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Highly correlated network dynamics underlie sharp wave-ripple activity in sleeping zebra finches, 14th Göttingen Meeting of German Society of Neuroscience, 22 March 2021, Online.
Janie Ondracek
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“Compartmentalization of brain activity during sleep in an avian brain” 113th Annual Meeting of the German Zoological Society, 30 August-3 September 2021, Online.
Hamed Yeganegi
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“Compartmentalization of brain activity during sleep in zebra finches” 14th Göttingen Meeting of German Society of Neuroscience, 22 March 2021, Online.
Hamed Yeganegi
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Multi-channel recordings reveal age-related differences in the sleep of juvenile and adult zebra finches. Cold Spring Harbor Laboratory.
Yeganegi, Hamed & Ondracek, Janie M.
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“Mammalian-like developmental changes are present in the neural signatures of avian sleep” 114th Annual Meeting of the German Zoological Society, 12-16 September 2022, Bonn, Germany.
Hamed Yeganegi
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“Sleep structure in juvenile and adult zebra finches: broad differences in EEG oscillations and functional connectivity” FENS Forum 2022, 9-13 July 2022, Paris, France.
Hamed Yeganegi
