Constraints on population dynamics across cortical and subcortical sensorimotor circuits
File(s)
Author(s)
Gallego Carracedo, Cecilia
Type
Thesis or dissertation
Abstract
Behaviour emerges from the coordinated activity across brain regions with distinct architectures. Each brain region produces specific neural signals that make specialised contributions to behaviour. However, the manner in which the distinct regional architectures shape the neural signals which ultimately produce behaviour remains poorly understood. The focus of this thesis was to study the neural signals from brain areas within the sensorimotor system with different architectures, and characterise their similarities and differences with respect to their architecture and functionality.
In the first part of the thesis, we characterised the relationship between local field potentials (LFPs) and neural population dynamics across three distinct regions of the primate sensorimotor cortex during a delayed reaching task. We found that the LFP band power was correlated with the neural population latent dynamics in a frequency-dependent and region-specific manner. The relationship remained stable across movement planning and execution, demonstrating that this relationship reflects architectural constraints rather than the specific neural process.
In the second part, to complement the previous study where the neural constraints were passively studied, we used an operant brain-computer interface (BCI) task in head-fixed mice running on a spherical treadmill to directly probe the constraints of distinct architectures on the volitional modulation of their brain activity. Animals demonstrated volitional modulation of neural activity in primary motor cortex (M1) and dorsolateral striatum (DLS), two highly connected regions within the sensorimotor system. The BCI-driven modulation had a markedly different spatial extent consistent with the architectural properties of each circuit, with localised modulation near BCI channels in DLS, and widespread modulation across M1.
Together, these findings demonstrate that circuit architecture imposes distinct constraints on the neural population signals across the sensorimotor system that shape their contributions to behaviour.
In the first part of the thesis, we characterised the relationship between local field potentials (LFPs) and neural population dynamics across three distinct regions of the primate sensorimotor cortex during a delayed reaching task. We found that the LFP band power was correlated with the neural population latent dynamics in a frequency-dependent and region-specific manner. The relationship remained stable across movement planning and execution, demonstrating that this relationship reflects architectural constraints rather than the specific neural process.
In the second part, to complement the previous study where the neural constraints were passively studied, we used an operant brain-computer interface (BCI) task in head-fixed mice running on a spherical treadmill to directly probe the constraints of distinct architectures on the volitional modulation of their brain activity. Animals demonstrated volitional modulation of neural activity in primary motor cortex (M1) and dorsolateral striatum (DLS), two highly connected regions within the sensorimotor system. The BCI-driven modulation had a markedly different spatial extent consistent with the architectural properties of each circuit, with localised modulation near BCI channels in DLS, and widespread modulation across M1.
Together, these findings demonstrate that circuit architecture imposes distinct constraints on the neural population signals across the sensorimotor system that shape their contributions to behaviour.
Version
Open Access
Date Issued
2026-06-04
Date Awarded
2026-08-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Gallego, Juan Alvaro
Publisher Department
Department of Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)