Calcium homeostasis restoration in pyramidal neurons through micrometer-scale wireless electrical stimulation in spinal cord injured mice.

Spinal Cord Injury (SCI) is a significant neurological disorder that can result in severe motor and cognitive impairments. Neuronal regeneration and functional recovery are critical aspects of SCI treatment, with calcium signaling being a crucial indicator of neuronal excitability. In this study, we utilized a murine model to investigate the effects of targeted wireless electrical stimulation (ES) on neuronal activity following SCI. After establishing a complete SCI model in normal mice, flexible electrodes were implanted, and targeted wireless ES was administered to the injury site. We employed fiber-optic photometric in vivo calcium imaging to monitor calcium signals in pyramidal neurons within the CA3 region of the hippocampus and the M1 region of the primary motor cortex. The experimental results demonstrated a significant reduction in calcium signals in CA3 and M1 pyramidal neurons following SCI (reduced by 76 % and 59 %, in peak respectively). However, the application of targeted wireless ES led to a marked increase in calcium signals in these neurons (increased by 118 % and 69 %, in peak respectively), indicating a recovery of calcium activity. These observations suggest that wireless ES has a positive modulatory effect on the excitability of pyramidal neurons post-SCI. Understanding these mechanisms is crucial for developing therapeutic strategies aimed at enhancing neuronal recovery and functional restoration following spinal cord injuries.

Exploring the Effect of Arsenic-Containing Hydrocarbon on the Bidirectional Synaptic Plasticity of the Dorsal Hippocampus.

Arsenic-containing hydrocarbons (AsHCs) are common in marine organisms. However, there is little research on their effects on the central nervous system's advanced activities, such as cognition. Bidirectional synaptic plasticity dynamically regulates cognition through the balance of long-term potentiation (LTP) and long-term depression (LTD). However, the effects of AsHCs on bidirectional synaptic plasticity and the underlying molecular mechanisms remain unexplored. This study provides the first evidence that 15 µg As L-1 AsHC 360 enhances bidirectional synaptic plasticity, occurring during the maintenance phase rather than the baseline phase. Further calcium gradient experiments hypothesize that AsHC 360 may enhance bidirectional synaptic plasticity by affecting calcium ion levels. The enhancement of bidirectional synaptic plasticity by 15 µg As L-1 AsHC 360 holds significant implications in improving cognitive function, treating neuro-psychiatric disorders, promoting neural recovery, and enhancing brain adaptability.

Design of a 1 × 4 micro-magnetic stimulation device and its targeted, coordinated regulation on LTP of Schaffer-CA1 in the hippocampus of rats.

Magnetic technology has been a hotspot of neuromodulation research in recent years. However, magnetic coil is limited by their size, and it is impossible to realize precise targeted magnetic stimulation to the target area at the cellular scale. To this end, this study designs a 1 × 4 array micro-magnetic stimulation (µMS) device with four sub-millimeter-sized elements, enabling precise magnetic stimulation of the CA1-CA3-DG tri-synaptic positions in the rat hippocampal region. First, it is determined that 70 KHz/2 mT/1 min magnetic stimulation parameter has a modulatory effect on the long-term potentiation (LTP) of Schaffer-CA1 in rat hippocampus. Then, a 1 × 4 array µMS device is used to perform magnetic stimulation at 70 KHz/2 mT/1 min, targeting the CA1, CA3, and DG regions individually with single-point magnetic stimulation; and multi-region magnetic stimulation is applied to the double-point targeting regions of CA1-CA3, CA1-DG, and CA3-DG, as well as the triple-point targeting region of CA1-CA3-DG, so as to investigate the regulation of LTP by single-region magnetic stimulation and multi-region magnetic stimulation. The experimental results indicate that, in the case of single-region magnetic stimulation, the magnitude of the increase in LTP in the CA1 region is the greatest, followed by the CA3 region, while the effect of magnetic stimulation on the DG region is less pronounced. In multi-region magnetic stimulation, synergistic magnetic stimulation of the three-point CA1-CA3-DG results in a greater increase in LTP compared to stimulation of two individual areas, and the enhancement of LTP induction with multi-region magnetic stimulation surpasses that of single-region stimulation. This study has implications for the collaborative targeted magnetic stimulation application of arrayed micro-magnetic devices.