Junkai Yin’s research while affiliated with National University of Defense Technology and other places

Neurite outgrowth and synapse formation constitute the cellular basis for the establishment and plasticity of neural networks, crucially involved in cognitive functions. However, the techniques currently available to effectively and specifically modulate these processes remain limited. In this work, we propose a non-drug and non-thermal terahertz (THz) photon modulation approach that enhances neuronal growth and synaptogenesis. Frequency screening experiments show that 34.5 THz photon stimulation could effectively promote neurite elongation and postsynaptic density protein 95 (PSD95) expression by 26.0% in rat hippocampal neurons. Subsequent cellular experiments reveal an upregulation of the cyclic adenosine monophosphate (cAMP) signaling pathway and adenylyl cyclase type 1 (AC1) activity after 34.5 THz photon irradiation. Molecular dynamics simulations suggest that 34.5 THz photons promote the binding between AC1 and ligand, accelerating cAMP generation. In vivo experiments further confirm an increase in hippocampal cAMP levels and dendritic spine density after THz photon stimulation, accompanied by a significant improvement in cognitive performance. Overall, our results suggest THz photon stimulation as an effective and specific method for neuromodulation, promising for future applications in the treatment of cognitive dysfunction.

Comorbid anxiety in chronic pain is clinically common, with a comorbidity rate of over 50%. The main treatments are based on pharmacological, interventional, and implantable approaches, which have limited efficacy and carry a risk of side effects. Here, we report a terahertz (THz, 10¹² Hz) wave stimulation (THS) technique, which exerts nonthermal, long-term modulatory effects on neuronal activity by reducing the binding between nano-sized glutamate molecules and GluA2, leading to the relief of pain and comorbid anxiety-like behaviors in mice. In mice with co-occurring anxiety and chronic pain induced by complete Freund’s adjuvant (CFA) injection, hyperactivity was observed in glutamatergic neurons in the anterior cingulate cortex (ACCGlu). Using whole-cell recording in ACC slices, we demonstrated that THS (34 THz) effectively inhibited the excitability of ACCGlu. Moreover, molecular dynamics simulations showed that THS reduced the number of hydrogen bonds bound between glutamate molecules and GluA2. Furthermore, THS target to the ACC in CFA-treatment mice suppressed ACCGlu hyperactivity and, as a result, alleviated pain and anxiety-like behaviors. Consistently, inhibition of ACCGlu hyperactivity by chemogenetics mimics THS-induced antinociceptive and antianxiety behavior. Together, our study provides evidence for THS as an intervention technique for modulating neuronal activity and a viable clinical treatment strategy for pain and comorbid anxiety.

Hepatocellular carcinoma (HCC) is one of the most common primary hepatic malignancies across the world. The annual incidence and death rates have increased at the highest rate of all cancers in recent years. Surgical resection is a potentially curative option for solitary HCC or unilobar disease without evidence of metastases or vascular invasion. This study focuses on the molecular differences between the HCC foci and paracancerous tissues and provides some valuable biomarkers based on the vibrational spectrum. Fourier transform infrared (FTIR) spectroscopy is a non-invasive and qualitative and semi-quantitative analysis technique that has been widely applied for the identification of macromolecular changes in biological tissues. In this study, the FTIR spectra of the HCC foci and the paracancerous tissues were recorded separately, and ten areas under the absorption peaks of all the specimens were calculated. The result demonstrates that the areas of protein-related absorption peaks at 1398 cm-1, 1548 cm-1, 1654 cm-1 and 3070 cm-1 may be the key indicators of the two different regions. After coupling with the classification algorithms of k-nearest neighbor (KNN), random forest (RF) and support vector machine (SVM), it was found that SVM with an RBF kernel performed best with the AUC (area under the ROC curve) reaching 0.997, and the performance was better than the feature based on the full spectrum. This reveals that the peak area-based FTIR spectra combined with the SVM algorithm may be a promising tool in identifying the HCC foci and the paracancerous tissues.