| The majority of neuroscience findings in the past decades have been centered on discoveries made at the microscale, serial exploration of single neurons, their molecular components, and the correlates these cells have to learning and behavior. Advances have been made at the macroscale, the imaging of populations of thousands to millions of cells, losing the resolution of a single neuron in exchange for knowledge about how large regions of the brain respond given certain stimuli or internally generated thoughts. To date, very little has bridged these two extremes. Neuroscience has developed a great understanding of how single neurons work coupled with being able to make generalized discretizations of the brain into regions. Neurons are highly interconnected, yet details about the mesoscale, the network substrate of the brain, still remain unknown. A fundamental hypothesis in neuroscience is that information is coded by patterns of cellular activation, a result of specific connectivity. Thus, these patterns are an elementary functional unit of information processing in the brain and simultaneously reveal the underlying structure of neural circuits. Here, I apply a top down approach at understanding cortical circuits by studying this emergent network activity resulting from individual neuron interaction and then use that knowledge to infer functional circuit representations, graphs. This is achieved using a novel algorithmic software technique to observe large populations of cells at heuristically optimal speeds. Through insight gained from the application of this method to primary auditory and somatosensory barrel field neocortex a principle of neuronal scaling can be observed. Further, through study of the dynamics of primary visual cortex, properties of efficient topophysical embedding and a modular nature suggest features of cortical circuits that may give rise to networks being capable of a high dynamic range of firing patterns. Ultimately, this work provides a foundation of insight into the functional mesocircuit networks across primary sensory cortex. |
