Dynamic Interlaminar and Thalamocortical Interaction Supported by Top-Down Beta Rhythms

The neocortex, as a great majority of the cerebral cortex, conceals multiple bands of oscillations recorded in local field potentials (LFPs), which are associated with different neural circuits and their corresponding brain functions. Not only are the complex neural connections in this area significant factors in the emergence of the cortical oscillations, but the inputs from the thalamus to the cortex along with cortical projections to dorsal thalamic nuclei and to the thalamic reticular nucleus as a part of the ventral nuclei as well. These cortical oscillations are related to sensory processing, memory, cognition, and motor control. Here, we developed a functional simulation model of the basic thalamocortical - corticothalamic loop architecture with detailed cortical laminar structure and a diverse set of neuron types. Our model generates prominent beta oscillations, and demonstrates the role of the time-varying bottom up inputs in the dynamics of beta oscillation in different layers of the cortex. Through excitatory top-down beta signals, which were strongly modulated based on frontal attentional inputs, two states were also modeled: Attended and Non-Attended.