Distributing task-related neural activity across a cortical network through task-independent connections

• Published in: Nature communications Vol. 14; no. 1; p. 2851
• Main Authors: Kim, Christopher M., Finkelstein, Arseny, Chow, Carson C., Svoboda, Karel, Darshan, Ran
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.05.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/116/1925; 631/378/116/2393; 631/378/2632/1663; 631/378/3920; 639/766/530/2801; Action Potentials - physiology; Circuits; Cortex (motor); Decision making; Firing pattern; Humanities and Social Sciences; Mental task performance; Models, Neurological; multidisciplinary; Neural networks; Neural plasticity; Neurons; Neurons - physiology; Perturbation; Science; Science (multidisciplinary); Synapses; Synapses - physiology
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-38529-y

Task-related neural activity is widespread across populations of neurons during goal-directed behaviors. However, little is known about the synaptic reorganization and circuit mechanisms that lead to broad activity changes. Here we trained a subset of neurons in a spiking network with strong synaptic interactions to reproduce the activity of neurons in the motor cortex during a decision-making task. Task-related activity, resembling the neural data, emerged across the network, even in the untrained neurons. Analysis of trained networks showed that strong untrained synapses, which were independent of the task and determined the dynamical state of the network, mediated the spread of task-related activity. Optogenetic perturbations suggest that the motor cortex is strongly-coupled, supporting the applicability of the mechanism to cortical networks. Our results reveal a cortical mechanism that facilitates distributed representations of task-variables by spreading the activity from a subset of plastic neurons to the entire network through task-independent strong synapses. Large scale neural recordings show that task-related activity is observed across neural circuits. Here, the authors have identified a network mechanism that promotes distributed activity in the cortex during decision-making via task-independent synapses.