NEURAL DYNAMICS IN THE CORTICO-BASAL GANGLIA-THALAMIC-CORTICAL LOOP UNDERLYING FLEXIBLE MOTOR TIMING
Date of Award
Fall 11-7-2025
Document Type
Dissertation
Publication Status
Version of Record
Submission Date
December 2025
Department
Biological Sciences
Degree Name
Doctor of Philosophy (PhD)
Thesis/Dissertation Advisor [Chair]
Hidehiko Inagaki
Abstract
The ability to flexibly time actions is a fundamental aspect of voluntary motor control. The frontal cortex and striatum exhibit ramping neural activity that predicts movement initiation, suggesting they function as a core timing circuit. However, the distinct computational roles of these highly interconnected regions and the specific cell types involved have remained elusive. This thesis investigates the neural mechanisms of motor timing by combining cell-type-specific perturbations, multi-regional electrophysiology, and computational modeling in mice. First, we demonstrate that the frontal cortex and striatum play complementary roles in an adjustable timing mechanism. Transiently silencing the frontal cortex effectively “pauses” the ramping activity in both regions, while inhibiting the striatum “rewinds” it, revealing that the striatum acts as a temporal integrator of cortical input. Second, we dissect the underlying microcircuit dynamics within the cortico-basal ganglia-thalamocortical (CBGTC) loop. By recording from and manipulating distinct striatal cell types (dSPNs and iSPNs) and the thalamus, we identify their specific contributions. To unify our empirical findings, we developed a biologically constrained multi-regional recurrent neural network (mRNN). Reverse-engineering this model revealed that the subcortical loop—comprising the striatum, other basal ganglia nuclei, and thalamus— collectively implements a line attractor. This population dynamics mechanism is responsible for generating the ramping activity that drives timed actions in the cortex. In conclusion, this work provides a multi-level account of motor timing. We propose that the frontal cortex initiates a timing command, which is then integrated and transformed into a precise ramp by a line attractor embedded within the subcortical CBGTC loop. This mechanism allows for the flexible and controlled initiation of volitional movement.
Recommended Citation
Yang, Zidan, "NEURAL DYNAMICS IN THE CORTICO-BASAL GANGLIA-THALAMIC-CORTICAL LOOP UNDERLYING FLEXIBLE MOTOR TIMING" (2025). Electronic Theses and Dissertations. 239.
https://digitalcommons.fau.edu/etd_general/239