Influence of altered serum and muscle concentrations of BDNF on electrophysiological properties of spinal motoneurons in wild-type and BDNF-knockout rats

Exercise-induced adaptation of neurons in the vertebrate locomotor system

Vertebrate neurons are highly dynamic cells that undergo several alterations in their functioning and physiologies in adaptation to various external stimuli. In particular, how these neurons respond to physical exercise has long been an area of active research. Studies of the vertebrate locomotor system's adaptability suggest multiple mechanisms are involved in the regulation of neuronal activity and properties during exercise. In this brief review, we highlight recent results and insights from the field with a focus on the following mechanisms: (a) alterations in neuronal excitability during acute exercise; (b) alterations in neuronal excitability after chronic exercise; (c) exercise-induced changes in neuronal membrane properties via modulation of ion channel activity; (d) exercise-enhanced dendritic plasticity; and (e) exercise-induced alterations in neuronal gene expression and protein synthesis. Our hope is to update the community with a cellular and molecular understanding of the recent mechanisms underlying the adaptability of the vertebrate locomotor system in response to both acute and chronic physical exercise.

Ononin ameliorates depression-like behaviors by regulating BDNF-TrkB-CREB signaling in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Ononin is a flavonoid compound found in several medicinal plants, including Astragalus membranaceus, Sophora flavescens, and Ononis spinosa. These plants have been traditionally used in various parts of the world for their medicinal properties, including anti-inflammatory, antioxidant, and antitumor effects. Major depression is a common, long-lasting, and recurrent psychiatric disorder with a high suicide rate. Naturally occurring flavonoids treat depression via poorly understood mechanisms.

AIM OF THE STUDY

The present study aimed to determine whether ononin conferred an antidepressant-like effect in PC12 cell models and chronic mild stress (CMS)-induced depressive rat models and to explore its possible mechanisms.

MATERIALS AND METHODS

Depression-related behaviors were measured using sucrose preference, tail suspension and open-field tests. Furthermore, to explore these mechanisms, we employed in vitro and in vivo assay methods, including neurite outgrowth, western blotting, quantitative RT-PCR, and staining methods.

RESULTS

Treatment with ononin or BDNF significantly increased PC12 cells' neuronal growth and differentiation. Furthermore, ononin promotes the activation of TrkB and growth factors and upregulates the PI3K/Akt and BDNF/TrkB/CREB signaling pathways. The in vitro results were consistent with CMS-induced depressive rat models, in which ononin treatment significantly decreased depression-like behaviors and activated TrkB, growth factors, and BDNF/TrkB/CREB signaling pathways in the frontal cortex and hippocampus. Depression-induced microscopic alterations in the frontal cortex and hippocampus of rats with CMS-induced depression were also mitigated following ononin treatment.

CONCLUSION

Based on these findings, we suggest that ononin is a promising antidepressant candidate for treating depression.

Comparison of the effects of BDNF/TRKB signalling on metabolic biomarkers in the liver of sedentary and trained rats with normal and knockout BDNF genotypes

Introduction: The effect of brain-derived neurotrophic factor (BDNF) on the modulation of metabolic processes in the liver is poorly understood. Therefore, the aim of this study was to investigate whether hepatic concentrations or activities of metabolic biomarkers depend on altered BDNF/TrkB content in the liver, resulting from different BDNF genotypes of rats. In addition, it was assessed whether 5-week moderate endurance training modifies the levels of BDNF/Trk-B signaling and studied hepatic markers. Methods: Experiments were performed on wild-type and heterozygous BDNF knockout (HET, SD-Bdnf) rats, which were divided into four groups: control with normal genotype (Bdnf+/+), control with BDNF knockout genotype (Bdnf+/-), trained with normal genotype (Bdnf+/+T) and trained with BDNF knockout genotype (Bdnf +/-T). BDNF/TrkB concentrations as well as selected metabolic biomarkers including lipids-total cholesterol (CHOL), low-density lipoprotein (LDL), triglycerides (TG); enzymes-alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP); hormones-insulin (INS) and leptin (LEPT) as well as interleukin-6 (IL-6) as regeneration indicator were measured directly in liver homogenates. Results and Discussion: The study showed that Bdnf+/- rats exhibited reduced BDNF/TrkB signaling (BDNF, p < 0.0001; Trk-B, p = 0.0005), altered lipid levels (CHOL, p < 0.0001; LDL, p < 0.0001; TG, p = 0.0006) and reduced hepatic ALAT (p = 0.0004) and GGT (p < 0.0001) activity, which may contribute to hepatic steatosis and obesity, as well as indicate impairment of specific metabolic pathways in the liver. Interestingly, endurance training did not alter hepatic BDNF and TrkB content, but improved ALAT (p = 0.0366) and ASAT (p = 0.0191) activities and increased hepatic IL-6 (p = 0.0422) levels in Bdnf +/- rats, suggesting enhanced liver regeneration in animals with BDNF allele loss.