Neuronal control of variable and hierarchical birdsong syntax: A synergistic cross-species study

• Applicant: Dr. Lena Veit
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 551970350

Our brain organizes movements and vocalizations in nested hierarchical sequences to produce behaviors ranging from mundanely brushing our teeth to our highly evolved speech. Despite the importance of hierarchical motor control to everyday life, little is known about its underlying neural mechanisms. In vertebrates, the flexible concatenation of motor elements is thought to rely on thalamocortical loops. Elucidating how these circuits control hierarchical syntax requires an animal model with behavior that shares the deep nested organization of many human behaviors. Here, we will use the complementary expertise of two PIs to study the function of thalamocortical circuits underlying hierarchical song syntax in two songbird species - Bengalese finches and canaries. The syllable sequences of these singers are flexible and compose a rich hierarchical syntax, with important species differences in the complexity of syntax - allowing us to ask questions which would not be possible to study in each species alone. Prior work on song production mechanisms revealed that ongoing production of stereotyped song sequences relies on a specialized thalamocortical loop circuit. Here, we build on our preliminary work showing that lesions to the cortical input of a different thalamocortical loop disrupts specifically the song's hierarchical syntax in variable singers - suggesting a model where an ongoing motor production loop is nested in another loop that controls syntax in longer time scales and deeper hierarchical syntax levels. Our synergistic research plan leverages sophisticated acoustic signal processing algorithms, electrophysiology, and micro-stimulation to elucidate the contribution of this loop in patterning hierarchical song syntax. Our work has the potential to expose a neural mechanism that controls vocal behavior in hierarchical levels and will pave the way for our future joint investigation of song premotor circuits that generate flexible and hierarchical syntax.

• DFG Programme: Research Grants
• International Connection: Israel
• International Co-Applicant: Professor Yarden Cohen, Ph.D.