A novel 3D-printed multi-driven system for large-scale neurophysiological recordings in multiple brain regions.

BACKGROUND: Electrical probes have been widely used for recording single-unit spike activity and local field potentials (LFPs) in brain regions. However, setting up an easily-assembled large-scale recording in multiple brain regions for long-term and stable neural activity monitoring is still a hard task. NEW METHOD: We established a novel 3D-printed multi-drive system with high-density (up to 256 channels) tetrodes/grid electrodes that enables us to record cortical and subcortical brain regions in freely behaving animals. RESULTS: In this paper, we described the design and fabrication of this system in detail. By using this system, we obtained successful recording on both spikes and LFPs from seven distinct brain regions that are related to memory function. COMPARISION WITH EXISTING METHODS: The low cost, large-scale electrodes with small size and flexible 3D-printed design of the system allow us to implant assembled tetrodes or grid electrodes into multiple target brain areas. CONCLUSIONS: The 3D-printed large-scale multi-drive platform we described here may serve as a powerful new tool for future studies of brain circuitry functions.

[The mechanism and function of hippocampal neural oscillation].

Neural oscillation is rhythmic or repetitive neural activity in the central nervous system that is usually generated by oscillatory activity of neuronal ensembles, reflecting regular and synchronized activities within these cell populations. According to several oscillatory bands covering frequencies from approximately 0.5 Hz to >100 Hz, neural oscillations are usually classified as delta oscillation (0.5-3 Hz), theta oscillation (4-12 Hz), beta oscillation (12-30 Hz), gamma oscillation (30-100 Hz) and sharp-wave ripples (>100 Hz ripples superimposed on 0.01-3 Hz sharp waves). Neural oscillation in different frequencies can be detected in different brain regions of human and animal during perception, motion and sleep, and plays an essential role in cognition, learning and memory process. In this review, we summarize recent findings on neural oscillations in hippocampus, as well as the mechanism and function of hippocampal theta oscillation, gamma oscillation and sharp-wave ripples. This review may yield new insights into the functions of neural oscillation in general.