Neuroscience
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Pain after spinal cord injury (SCI) can be difficult to treat. Drugs that target the opioid receptor (OR) outside the central nervous system (CNS) have gained increasing interest in pain control owing to their low risk of central side effects. Asimadoline and ICI-204448 are believed to be peripherally restricted KOR agonists withlimited access to the CNS. ⋯ High-dose ICI-204448 (10 mg/kg, s.c.) attenuated the increased fluorescence intensity of lumbar DRG neurons activated by a noxious pinch (400 g) stimulation in SCI mice. In conclusion, systemic administration of ICI-204448 achieved SCI pain inhibition at doses that did not induce notable side effects and attenuated DRG neuronal excitability which may partly contribute to its pain inhibition. These findings suggest that peripherally restricted KOR agonists may be useful for treating SCI pain, but the therapeutic window must be carefully examined.
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Sonogenetics is preferred for neuroregulation and the treatment of brain diseases due to its noninvasive properties. Ultrasonic stimulation produces thermal and mechanical effects, among others. Since transient receptor potential vanilloid 1 (TRPV1) could be activated at 42 °C, it is overexpressed in the M1 region of the mouse motor cortex to sense the change of temperature upon being stimulated by focused ultrasound. ⋯ Furthermore, when the temperature is >42 °C, the peak-to-peak value of the EMG signal for mice with TRPV1 overexpression in the M1 region was higher than that for mice without TRPV1 overexpression. The immunohistochemical results showed that ultrasound was not harmful to the stimulation site. The noninvasive ultrasound stimulation combined with thermosensitive protein TRPV1 overexpressed in neurocytes as sonothermogenetics technology has great potential to be used for the treatment of neurological diseases.
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Morphine has a strong analgesic effect and is suitable for various types of pain, so it is widely used. But long-term usage of morphine can lead to drug tolerance, which limits its clinical application. The complex mechanisms underlying the development of morphine analgesia into tolerance involve multiple nuclei in the brain. ⋯ Existing studies show that dopamine receptors and μ-opioid receptors participate in morphine tolerance through the altered activities of dopaminergic and/or non-dopaminergic neurons in the VTA. Several neural circuits related to the VTA are also involved in the regulation of morphine analgesia and the development of drug tolerance. Reviewing specific cellular and molecular targets and related neural circuits may provide novel precautionary strategies for morphine tolerance.
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Age modifies walking balance and neuromuscular control. Cognitive and postural constraints can increase walking balance difficulty and magnify age-related differences. However, how such challenges affect neuromuscular control remains unknown. ⋯ Arm-crossing also reduced walking balance mostly in OA, but step speed decreased mainly in YA, in whom the margin of stability increased. Arm-crossing reduced the complexity of synergies. Age, cognitive task, and arm position affect differently muscle synergy recruitment but have similar effects on walking balance.
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Motor imagery (MI) is a brain-computer interface (BCI) technique in which specific brain regions are activated when people imagine their limbs (or muscles) moving, even without actual movement. The technology converts electroencephalogram (EEG) signals generated by the brain into computer-readable commands by measuring neural activity. Classification of motor imagery is one of the tasks in BCI. ⋯ Finally, the processed data is input into the encoder layer of the Transformer for a self-attention calculation to obtain the classification results. Our approach was tested on the well-known MI datasets BCI Competition IV 2a and 2b, and the results show that the 2a dataset has a global average classification accuracy of 83.3% and a kappa value of 0.78. Experimental results show that the proposed method outperforms most of the existing methods.