Online Lecture by Swathi Sheshadri

Separate groups of beta and low frequency neurons form behavior- and state-dependent networks in the macaque fronto-parietal grasping circuit

Oscillatory synchrony in distinct frequency bands in the brain is strongly related to different cognitive and behavioral processes. For a better mechanistic understanding of how oscillatory synchronization coordinates task-dependent neuronal communication, it is essential to examine dynamic oscillatory network structure at the level of their origin: networks of neurons. In macaque monkeys performing a delayed grasping task, we estimated oscillatory network structure underlying behavioral epochs and conditions by computing pairwise phase consistency between neurons and LFPs recorded simultaneously from 128 electrodes implanted in premotor area F5 and parietal area AIP. Neurons were preferentially synchronized either in the low (3-6 Hz) or beta frequency band (17-35 Hz), forming separate networks with strong area- and time-specificity. Low frequency synchrony was predominant in F5 neurons during the cue and movement epochs while beta synchrony was predominant in AIP neurons during the fixation and memory epochs. Distinct network patterns were observed for context-types as well as grip-types of the task during the cue and memory epochs both in low frequency and beta networks. In contrast, low frequency networks were distinct during the movement epoch only for grip-types, thus revealing flexible and behavior-related network reconfigurations. Furthermore, a sub-group of strongly phase locked neurons contributed maximally to network reconfiguration in networks of both frequencies. These findings together might provide a framework for biologically plausible mechanistic models of flexible information processing coordinated by oscillatory synchrony.Supported by: German Research Foundation (DFG) SCHE ¹⁵⁷⁵⁄₁-1 & 3-1