Animals ; Mice ; Motor Neurons/physiology* ; Spinal Cord

In recent years, the study of autophagy in spinal cord injury (SCI) gradually becomes the hot spot. However, the function of autophagy in the injured spinal cord is still controversial. In order to further understand the role of autophagy after SCI, we summarized the activation of autophagy, autophagic cell death, the relationship between autophagy and apoptosis, the function of autophagy in promoting the molecular metabolism and the role of autophagy after spinal cord injury. We concluded that the role of autophagy after SCI is a double-edged sword. Upregulating the level of autophagy appropriately can promote damaged proteins metabolism and inhibit apoptosis. However, excessive activation of antophagy may induce autophagic cell dealth. So we consider that the proper regulation of autophagy will be a new target in the treatment of SCI.
Animals ; Apoptosis ; Autophagy ; physiology ; Humans ; Spinal Cord Injuries ; etiology ; pathology

This review systematically introduces the functional connections among cardiovascular centers from spinal cord to cortex, and the mechanisms underlying pressor or depressor response of these cardiovascular centers, including the pathways, transmitters and receptors involved. The pressor or depressor response of these cardiovascular centers is mainly mediated by RVLM-sympathetic vasoconstrictor nerve system.
Blood Pressure ; physiology ; Central Nervous System ; physiology ; Cerebral Cortex ; physiology ; Humans ; Hypothalamus ; physiology ; Medulla Oblongata ; physiology ; Spinal Cord ; physiology

Pain is a multi-dimensional emotional experience, and pain sensation and pain emotion are the two main components. As for pain, previous studies only focused on a certain link of the pain transmission pathway or a certain key brain region, and there is a lack of evidence that connectivity of brain regions is involved in pain or pain regulation in the overall state. The establishment of new experimental tools and techniques has brought light to the study of neural pathways of pain sensation and pain emotion. In this paper, the structure and functional basis of the neural pathways involved in the formation of pain sensation and the regulation of pain emotion in the nervous system above the spinal cord level, including thalamus, amygdala, midbrain periaqueductal gray (PAG), parabrachial nucleus (PB) and medial prefrontal cortex (mPFC), are reviewed in recent years, providing clues for the in-depth study of pain.
Humans ; Pain ; Neural Pathways/physiology* ; Periaqueductal Gray/physiology* ; Brain ; Spinal Cord/physiology* ; Magnetic Resonance Imaging

To understand how the nervous system develops from a small pool of progenitors during early embryonic development, it is fundamentally important to identify the diversity of neuronal subtypes, decode the origin of neuronal diversity, and uncover the principles governing neuronal specification across different regions. Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed, leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge. In this review, we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes, including predetermined, stochastic, and cascade diversifying models, and elaborate how these strategies are implemented in distinct regions such as the neocortex, spinal cord, retina, and hypothalamus. Importantly, the identity of neural progenitors is defined by their spatial position and temporal patterning factors, and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes. Microenvironmental cues, spontaneous activity, and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions. The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy, as well as understanding the organization of functional neural circuits and the evolution of the nervous system.
Humans ; Neural Stem Cells/physiology* ; Neurons/physiology* ; Brain ; Spinal Cord ; Embryonic Development ; Cell Differentiation/physiology*

OBJECTIVETo explore the recording method of the electrophysiological signals in corticospinal tract (CST) of adult rats by plugging microelectrodes and analyze the characteristics of these signals. These could provide some valuable and basic neural electrophysiological information for further research of recovering and refunctioning after spinal cord injury.

METHODSThe microelectrodes were plugged into the corticospinal tract at the T8 spinal section of Sprague-Dawley rats and the neuro-electrical signals were identified and recorded from CST by means of the Cerebus System. The characteristics of the recorded signals were described with the help of the Offline sorter and Neuroexplorer softwares, including the wavelength, amplitude, discharging frequency, the synchrony among the multi-discharging units from the same electrode and two different electrodes, analysis of interspike interval (ISI), etc.

RESULTSThe continuous and steady spontaneous electrophysiological signals were recorded from CST. Three or four types of discharging signals originated from different discharging units were collected with each electrode. The waveform of the signals appeared bidirectional. The wavelengths were 0.6 - 1.3 ms with wave amplitudes at a grade of hundred microvoltage and high signal-noise ratios. The LFB staining proved that the electrodes were accurately plugged into the corticospinal tract.

CONCLUSIONThe neuro-electrical signals at a grade of hundred microvoltage could be recorded stably from the corticospinal tract of rats by the Cerebus System with the microelectrodes, which provided valuable and basic neural electrophysiological information for further research on recovering and refunctioning after spinal cord injury (SCI) by analyzing the characteristics of electrophysiological signals.

Animals ; Electrodes, Implanted ; Electrophysiological Phenomena ; physiology ; Evoked Potentials, Motor ; physiology ; Male ; Microelectrodes ; Pyramidal Tracts ; physiology ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; physiology ; Spinal Cord Injuries ; physiopathology

Full evidence and obvious reasons made it possible to arrive at the conclusion that the nature of transmission upon cerebrospinal neurons is overwhelmingly mechanical, not only in the periphery- between various receptors and afferent nerve terminals, and between surrounding tissues and free nerve endings- but also in the cerebral cortex. When viewed from the standpoint of the everchanging patterns of natural mechanical stimuli, the neurons in the conscious cerebral cortex and the pain endings in an acute inflammatory locus have the same situation very much in common. It is quite likely that natural mechanical stimuli dominate over cerebrospinal nervous phenomena and physiologists have been watching the missing mechanism at work in every experiment upon afferent nerve terminals and cerebral cortex that they have done. The terms "psychic tension" and "central excitatory state" comparable to muscular tonus are of interest because they involve the use of mathematical techniques in psychology and neurophysiology. They are capable of becoming weak or strong, and they serve as an inner stimulus to give impetus to behavior. Unfortunately, however, it is an elusive inner stimulus, and it defies a lucid definition. But natural mechanical stimuli embody the psychic tension and the central excitatory state ultimately. It seems now that we just found a place where constant complaints against neurophysiology and physiological psychology are ventilated. We may conclude that natural mechanical stimuli are the leading direct stimuli to cerebrospinal neurons in the human body, and the plastic and developmental nervous phenomena and mental phenomena can be explained objectively by a familliar datum of mechanical energy and that we can reasonably expect the day of regarding material world and spiritual world in the monistic conception of matter-energy system.
Animals ; Anura ; Cerebral Cortex/*physiology ; Human ; In Vitro ; Motor Neurons/physiology ; Nerve Endings/physiology ; Receptors, Sensory/*physiology ; Spinal Cord/*physiology

Acupuncture analgesia is involved in various functions of the whole nervous system. The spinal cord is the first station for processing and translating the acupuncture analgesia; the brain stem is the relay station for systematization, differentiation and analysis, excitation, synthesis of acupuncture analgesic message, playing an important role in acupuncture analgesia; the thalamus functions complicated analysis and comprehensive regulation on various messeges with many kinds of neurohumoral factors involved and it is a coordinate center for strengthening and controlling acupuncture analgesia; the limbic system and its nuclear groups with many neurotransmitters involved, play coordinate action on acupuncture analgesia; the cerebral cortex is the high center and functions not only excitation and inhibition processes, but also is a center for complicated regulation and command, strengthening acupuncture analgesia and inhibiting the excess, so as to exerts interaction of dynamic balance.
Acupuncture Analgesia ; Brain Stem ; physiology ; Cerebral Cortex ; physiology ; Humans ; Limbic System ; physiology ; Pain ; physiopathology ; Spinal Cord ; physiology ; Thalamus ; physiology

Electric field stimulation (EFS) can effectively inhibit local Ca ²⁺ influx and secondary injury after spinal cord injury (SCI). However, after the EFS, the Ca ²⁺ in the injured spinal cord restarts and subsequent biochemical reactions are stimulated, which affect the long-term effect of EFS. Polyethylene glycol (PEG) is a hydrophilic polymer material that can promote cell membrane fusion and repair damaged cell membranes. This article aims to study the combined effects of EFS and PEG on the treatment of SCI. Sprague-Dawley (SD) rats were subjected to SCI and then divided into control group (no treatment, n = 10), EFS group (EFS for 30 min, n = 10), PEG group (covered with 50% PEG gelatin sponge for 5 min, n = 10) and combination group (combined treatment of EFS and PEG, n = 10). The measurement of motor evoked potential (MEP), the motor behavior score and spinal cord section fast blue staining were performed at different times after SCI. Eight weeks after the operation, the results showed that the latency difference of MEP, the amplitude difference of MEP and the ratio of cavity area of spinal cords in the combination group were significantly lower than those of the control group, EFS group and PEG group. The motor function score and the ratio of residual nerve tissue area in the spinal cords of the combination group were significantly higher than those in the control group, EFS group and PEG group. The results suggest that the combined treatment can reduce the pathological damage and promote the recovery of motor function in rats after SCI, and the therapeutic effects are significantly better than those of EFS and PEG alone.
Animals ; Electric Stimulation ; Polyethylene Glycols/therapeutic use* ; Rats ; Rats, Sprague-Dawley ; Recovery of Function/physiology* ; Spinal Cord ; Spinal Cord Injuries/therapy*

OBJECTIVE: To summarize the research progress of stem cell transplantation in treating spinal cord injury (SCI) at different stages based on the pathophysiological mechanism of SCI. METHODS: The relevant research literature at home and abroad was extensively reviewed to explore the impact of transplantation timing on the effectiveness of stem cell transplantation in treating SCI. RESULTS: Researchers performed different types of stem cell transplantation for subjects at different stages of SCI through different transplantation approaches. Clinical trials have proved the safety and feasibility of stem cell transplantation at acute, subacute, and chronic stages, which can alleviate inflammation at the injured site and restore the function of the damaged nerve cells. But the reliable clinical trials comparing the effectiveness of stem cell transplantation at different stages of SCI are still lacking. CONCLUSION Stem cell transplantation has a good prospect in treating SCI. In the future, the multi-center, large sample randomized controlled clinical trials are needed, with a focus on the long-term effectiveness of stem cell transplantation.
Humans ; Hematopoietic Stem Cell Transplantation ; Neurons ; Recovery of Function/physiology* ; Spinal Cord ; Spinal Cord Injuries/surgery* ; Stem Cell Transplantation