The burst of electrophysiological signals in the suprachiasmatic nucleus of mouse during the arousal detected by microelectrode arrays

Abstract

The neural mechanisms of torpor have essential reference significance for medical methods and long-term manned space. Changes in electrophysiology of suprachiasmatic nucleus (SCN) conduce to revealing the neural mechanisms from the torpor to arousal. Due to the lower physiology state during the torpor, it is a challenge to detect neural activities in vivo on freely behaving mice. Here, we introduced a multichannel microelectrode array (MEA) for real-time detection of local field potential (LFP) and action potential (spike) in the SCN in induced torpor mice. Meanwhile, core body temperature and behaviors of mice were recorded for further analysis. Platinum nanoparticles (PtNPs) and Nafion membrane modified MEA has a lower impedance (16.58 ± 3.93 kΩ) and higher signal-to-noise ratio (S/N = 6.1). We found that from torpor to arousal, the proportion of theta frequency bands of LFPs increased, spike firing rates rapidly increased. These results could all be characteristic information of arousal, supported by the microscopic neural activity promoting arousal in mice. MEA displayed real-time dynamic changes of neuronal activities in the SCN, which was more helpful to analyze and understand neural mechanisms of torpor and arousal. Our study provided a factual basis for the neural state in SCN of induced non-hibernating animals, which was helpful for the application of clinics and spaceflight.

A Microelectrode Array Modified by PtNPs/PB Nanocomposites Used for the Detection and Analysis of Glucose-Sensitive Neurons under Different Blood Glucose States

“…It had an edge-of-shank to the edge-of-shank spacing of 80 μm (center-of-shank to center-of-shank spacing of 200 μm), covering a large area of VMH. The fabrication of MEA was depicted in Figure a, experiencing three runs of photolithography to synthesize the substrate (Si/SiO 2 : 25 μm/200 nm), conducting (Ti/Pt: 30 nm/250 nm), and insulating layers (SiO 2 /Si 3 N 4 : 300 nm/500 nm)), following the same fabrication as previously described . It was achieved with Plasma Enhanced Chemical Deposition, photolithography, the CHF 3 Reactive Ion Etching, and Inductively Coupled Plasma Deep Reactive Ion Etching (Figure a).…”

PtNPs/PEDOT:PSS-Modified Microelectrode Arrays for Detection of the Discharge of Head Direction Cells in the Retrosplenial Cortex of Rats under Dissociation between Visual and Vestibular Inputs

“…In addition, MEAs prepared using MEMS technology have good uniformity and their planar site can be modified with nanomaterials to improve detection performance [20]. Indeed, Pt nanoparticles (PtNPs) have the advantages of high surface area and high conductivity, which can significantly enhance the ability to detect weak signals [21]. As a conductive polymer, poly(3,4-ethylene dioxythiophene) (PEDOT) has been verified as having a low Young's modulus and good biocompatibility [19], and has been widely used in the biomedical field.…”