The Role of Fgf9 in the Antidepressant Effects of Exercise and Fluoxetine in Chronic Unpredictable Mild Stress Mice

Role of SIRT1-mediated synaptic plasticity and neurogenesis: Sex-differences in antidepressant-like efficacy of catalpol

BACKGROUND

Catalpol, an important compound found in Rehmannia glutinosa (a plant with high nutritional and antidepressant medicinal value), exhibits various biological activities and has the ability to penetrate the blood-brain barrier. Our recent studies revealed a gender difference in the antidepressant activity of Rehmannia glutinosa with females showing better responses than males. Catalpol is likely the key compound responsible for this gender-specific difference, which caters to current clinical observations that the severity and impact of depression are approximately two to three times higher in females than in males. However, the sex-specific mechanism of catalpol's antidepressant effects remains unclear.

PURPOSE AND METHODS

Our recent molecular network predictions suggest that the gender-specific antidepressant properties of catalpol primarily involve the regulation of SIRT1-mediated synaptic plasticity and neurogenesis. Building on this, the present study used a well-established chronic unpredictable mild stress model of depression in mice to confirm the sex-specific antidepressant characteristics of catalpol over time and intensity. Furthermore, using SIRT1 inhibitors and activators, behavioral tests, hematoxylin & eosin, Nissl, and Golgi staining, western blotting, immunofluorescence, and real-time PCR, we evaluated the key indicators of depressive behavior, synaptic plasticity, and neurogenesis before and after SIRT1 intervention to comprehensively assess whether the sex-specific antidepressant mechanism of catalpol indeed involves SIRT1-mediated synaptic plasticity and neurogenesis.

RESULTS

The gender-dependent antidepressant effects of catalpol are characterized by a faster onset and stronger effects in females compared to males, with females showing stronger regulation of SIRT1-mediated synaptic plasticity and neurogenesis. Activation of SIRT1 preserved the gender differences in catalpol's effects on depressive behavior, hippocampal synaptic plasticity (including neuronal consolidation, neuronal density, dendritic spines, and PSD95 and SYP gene and protein expression), and neurogenesis (including enhancement of GAP43 and MAP2 expression, activation of c-myc, cyclinD1, Ngn2, and NeuroD1 mRNA levels, and upregulation of the Wnt3a/β-catenin/GSK-3β pathway), while inhibition of SIRT1 abolished these gender differences in the effects of catalpol.

CONCLUSIONS

Catalpol exhibits higher antidepressant activity in female mice compared to male mice, and the mechanism underlying this gender difference in antidepressant effects may depend on catalpol's higher sensitivity in improving hippocampal SIRT1-mediated synaptic plasticity and neurogenesis in females. The novelty of this study lies in its first-time revelation of the gender-specific phenotypes, targets, and molecular mechanisms of the antidepressant effects of catalpol.

Kappa opioid receptor in nucleus accumbens regulates depressive-like behaviors following prolonged morphine withdrawal in mice

Prolonged withdrawal from opioids leads to negative emotions. Kappa opioid receptor (KOR) plays an important role in opioid addiction and affective disorders. However, the underlying mechanism of KOR in withdrawal-related depression is still lacking. We found that escitalopram treatment had a limited effect in improving depression symptoms in heroin-dependent patients. In mice, we demonstrated prolonged (4 weeks) but not acute (24 h) withdrawal from morphine induced depressive-like behaviors. The number of c-Fos positive cells and the expression of KOR in the nucleus accumbens (NAc), were significantly increased in the prolonged morphine withdrawal mice. Conditional KOR knockdown in NAc significantly improved depressive-like behaviors. Repeated but not acute treatment with the KOR antagonist norBNI improved depressive-like behaviors and reversed PSD95, synaptophysin, p-ERK, p-CREB, and BDNF in NAc. This study demonstrated the important role of striatal KOR in morphine withdrawal-related depressive-like behaviors and offered therapeutic potential for the treatment of withdrawal-related depression.

IMPACTS OF SUSPENSION TRAINING ON THE PHYSICAL FITNESS OF SWIMMERS

ABSTRACT Introduction Suspension training develops the physical fitness of a swimmer and improves his or her abilities. The specific fitness of a swimmer is the body's ability to adapt to load in swimming. This is also a comprehensive reflection of their physical function, conditioning, athletic ability, and overall health. Objective This study aimed to analyze the effect of suspension training on swimmers’ balance, abdominal center strength, and athletic performance. Methods This paper selects several swimmers as research volunteers. They were randomly divided into experimental and control groups. Both of them underwent physical training for three months. The experimental group adopted the suspension training method. The control group used traditional training methods. Mathematical statistics performed data analysis in both groups. Results The physical fitness of the two groups of swimmers was improved substantially after the experiment (P<0.05). The strength balance ability of the experimental group showed better performance(P<0.05). There was a significant difference between the experimental and control groups in the results of fitness index tests (P<0.01). Conclusion Suspension training has a prominent effect on the physical development of swimmers. This modality proved a better efficacy on swimmers’ performance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

High-frequency repetitive transcranial magnetic stimulation mitigates depression-like behaviors in CUMS-induced rats via FGF2/FGFR1/p-ERK signaling pathway

High-frequency repetitive transcranial magnetic stimulation (rTMS) is a widely used and effective biological treatment for depression. Although previous studies have shown that astrocyte function may be modified by rTMS, the specific neurobiological mechanisms underlying its antidepressant action are not clear. Substantial evidence has accumulated indicating that neurotrophin dysfunction and neuronal apoptosis play a role in the development of depression. To evaluate this hypothesis, we applied a chronical unpredictable mild stress (CUMS) protocol to induce depression-like behaviors in rats, followed by the delivery of 10-Hz rTMS for 3 weeks. Behavioral outcome measures consisted of a sucrose preference test, forced swimming test, and open field test. Histological analysis focused on apoptosis, expression of GFAP and FGF2, and FGF2 pathway-related proteins. The results showed that after rTMS treatment, the rats' sucrose preference increased, open field performance improved while the immobility time of forced swimming decreased. The behavioral changes seen in rTMS treated rats were accompanied by marked reductions in the number of TUNEL-positive neural cells and the level of expression of BAX and by an increase in Bcl2. Furthermore, the expression of GFAP and FGF2 was increased, along with activation of FGF2 downstream pathway. These results suggest that rTMS treatment can improve depression-like behavior, attenuate neural apoptosis, and reverse reduction of astrocytes in a rat model of depression. We hypothesize that the therapeutic action of rTMS in CUMS-induced rats is linked to the activation of the FGF2/FGFR1/p-ERK signaling pathway.