A new perspective on hippocampal synaptic plasticity and post-stroke depression

Modulation of netrin-1/DCC signaling pathway by Jiawei Kongsheng Zhenzhong Pill improves synaptic structural plasticity in PSD rats

Jiawei Kongsheng Zhenzhong Pill(JKZP) is based on Kongsheng Zhenzhong Pill contained in the Tang Dynasty's "Thousand Golden Prescriptions," which exhibited good anti-ischemic and antidepressant effects in the previous study. However, its specific effects on post-stroke depression (PSD) and the mechanism are not clear. This study aimed to investigate the effects of JKZP in the treatment of PSD and related mechanisms. The decoction of JKZP was first analyzed for its medicinal chemical composition and screened for representative components of JKZP. The Middle cerebral artery occlusion (MCAO) method combined with solitary rearing and chronic unpredictable mild stress (CUMS) was used to establish a rat model of PSD, and to observe the effects of JKZP on the behavior and synaptic plasticity of PSD rats, and to investigate the mechanism of JKZP in the treatment of PSD by detecting the mRNA level, protein expression and activity of Netrin-1/DCC signaling pathway-related proteins. The results showed that the JKZP decoction contained loganin, β-asarone and other pharmaceutical ingredients, which have been reported to protect against cerebral ischemic injury and antidepressant effects. JKZP significantly improved the depression-like behavior of PSD rats and improved the damage to pyramidal neurons in the medial prefrontal cortex (mPFC) of PSD rats. Moreover, JKZP increased the density of dendritic spines in the mPFC of PSD rats, improved synaptic gap width and thickness of the post-synaptic density, and increased the number of synaptic vesicles. The results of Real-Time quantitative reverse transcription PCR (qRT-PCR), Western blotting, and pull-down assays revealed that JKZP increased netrin-1, deleted in colorectal cancer (DCC), and focal adhesion kinase (FAK) mRNA and protein expression, elevated the p-FAK/FAK ratio, and decreased myosin II protein expression and Ras homolog gene family member A (RhoA-GTP) activity in the mPFC of PSD rats. Taken together, JKZP can affect synaptic structural remodeling and improve depressive manifestations and neuronal damage in PSD rats by regulating the expression and activity of signaling molecules related to the netrin-1/DCC signaling pathway.

Cognitive behavioural therapy for depression, quality of life, and cognitive function in the post-stroke period: systematic review and meta-analysis

The post-stroke period is associated with a lot of sequelae, including depression, decreased quality of life, and decline of cognitive function. Apart from the pharmacotherapy, it is also important to find a non-pharmacological treatment to relieve the sequelae. Cognitive behavioural therapy (CBT) might be a potential candidate, which can be clarified by a systematic review and meta-analysis. The eligible criteria of enrolled studies in the systematic review and meta-analysis were the randomised clinical trials (RCTs) using CBT to treat post-stroke depression, or with the focus on quality of life or cognitive function in the post-stroke period. The endpoint scores of depression, quality of life, and cognitive function scales were the targeted outcome for the final meta-analysis in the random effects model. Ten RCTs with 432 post-stroke patients receiving CBT and 385 controls were included. The meta-analysis results showed significant improvements in depression severity and quality of life. However, no significant difference between CBT and control groups was found in cognitive function. In addition, significant heterogeneity was derived from the meta-analysis. According to the meta-analysis results, CBT might be beneficial for relieving depression severity and improving quality of life. However, cognitive function might not be influenced by CBT. Further studies with a more consistent CBT design with greater sample sizes should be warranted to clarify and confirm the treatment effects of CBT for post-stroke depression and quality of life.

Three-needle electroacupuncture ameliorates depressive-like behaviors in a mouse model of post-stroke depression by promoting excitatory synapse formation via the NGL-3/L1cam pathway

Three-needle electroacupuncture (TNEA) has shown promise as a non-pharmacological treatment for post-stroke depression (PSD). However, the underlying mechanisms of its therapeutic effects remain unclear. In this study, we investigated the potential molecular and synaptic mechanisms by which TNEA ameliorates depressive-like behaviors in a mouse model of PSD. Male C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO) to induce PSD and subsequently treated with TNEA for three weeks at specific acupoints (GV24 and bilateral GB13). Through a combination of behavioral tests, neuronal activation assessment, synaptic function examination, transcriptomic analysis, and various molecular techniques, we found that TNEA treatment significantly improved anxiety and depressive-like behaviors in PSD mice. These improvements were accompanied by enhanced neuronal activation in the medial prefrontal cortex (mPFC) and primary somatosensory cortex (PSC), as well as the promotion of excitatory synapse formation and transmission function in the mPFC. Transcriptomic analysis revealed that TNEA upregulated the expression of Netrin-G Ligand-3 (NGL-3), a postsynaptic cell adhesion molecule, in the mPFC. Further investigation showed that the extracellular domain of NGL-3 binds to the presynaptic protein L1cam, promoting the formation of Vesicular Glutamate Transporter 1 (vGluT1) puncta on neuronal dendrites. Notably, cortical neuron-specific knockout of NGL-3 abolished the antidepressant-like effects of TNEA in PSD mice, confirming the crucial role of the NGL-3/L1cam pathway in mediating the therapeutic effects of TNEA. These findings provide novel insights into the molecular and synaptic mechanisms underlying the therapeutic effects of acupuncture in the treatment of PSD and highlight the potential of targeting the NGL-3/L1cam pathway for the development of alternative interventions for PSD and other depressive disorders.

Exercise-induced neuroplasticity: a new perspective on rehabilitation for chronic low back pain

Chronic low back pain patients often experience recurrent episodes due to various peripheral and central factors, leading to physical and mental impairments, affecting their daily life and work, and increasing the healthcare burden. With the continuous advancement of neuropathological research, changes in brain structure and function in chronic low back pain patients have been revealed. Neuroplasticity is an important mechanism of self-regulation in the brain and plays a key role in neural injury repair. Targeting neuroplasticity and regulating the central nervous system to improve functional impairments has become a research focus in rehabilitation medicine. Recent studies have shown that exercise can have beneficial effects on the body, such as improving cognition, combating depression, and enhancing athletic performance. Exercise-induced neuroplasticity may be a potential mechanism through which exercise affects the brain. This article systematically introduces the theory of exercise-induced neuroplasticity, explores the central effects mechanism of exercise on patients with chronic low back pain, and further looks forward to new directions in targeted neuroplasticity-based rehabilitation treatment for chronic low back pain.

Ginsenoside Rb1 protects hippocampal neurons in depressed rats based on mitophagy-regulated astrocytic pyroptosis

BACKGROUND

Astrocytes play a vital role in offering functional support for neurons, which are related to the pathogenic mechanism of depression. Ginsenoside Rb1 (GRb1) is demonstrated with antidepressant-like activities.

PURPOSE

We aimed to investigate whether GRb1 can inhibit mitophagy-mediated astrocytic pyroptosis to protect neurons in depression.

STUDY DESIGN

Model rats were subjected to chronic unpredictable mild stress (CUMS) for determining the in vivo antidepressant activity of GRb1.

METHODS

The mitophagy-mediated antipyroptosis role of GRb1 was assessed in lipopolysaccharide (LPS) + ATP-stimulated astrocytes. The mechanism by which GRb1 protects synaptic plasticity was investigated using hippocampal neurons incubated in an astrocyte medium. The rat depressive-like behaviors were determined through sucrose preference, forced swimming, and the open-field tests. Escitalopram was used in the anti-depression control of GRb1. Cyclosporin A (CsA), a mitophagy inhibitor, and interleukin (IL)-1β were used to reverse the role of GRb1 in mitophagy and pyroptosis, respectively.

RESULTS

GRb1 inhibited LPS-induced inflammation and activation in the astrocytes and repressed nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Also, GRb1 repressed LPS + ATP-promoted astrocytic pyroptosis. During GRb1 treatment, the activation of mitophagy with a decrease in ROS was observed in LPS + ATPs-stimulated astrocytes. CsA enhanced GRb1-decreased ROS and promoted astrocytic pyroptosis. The GRb1-treated astrocyte medium suppressed neuron death and increased neuron viability and synaptic density. Escitalopram and GRb1 improved the depressive-like behaviors of the rats. GRb1 activated mitophagy and inhibited astrocytic activation and pyroptosis in rats with depression. It also reduced impairments in synaptic structures and increased synaptic density in depressive-like rats. IL-1β increased astrocytic pyroptosis and reversed GRb1-enhanced synaptic plasticity in the rats exposed to CUMS. There were no statistical changes in depressive-like behaviors between GRb1 and Escitalopram groups.

CONCLUSION

GRb1 modulates mitophagy and the NF-κB pathway to inhibit astrocytic pyroptosis, thereby maintaining neurological homeostasis by repressing inflammation and enhancing synaptic plasticity.