Antidepressant-like effect of brain-derived neurotrophic factor (BDNF)

Modulation of Brain-derived Neurotrophic Factor Expression by Physical Exercise in Reserpine-induced Pain-depression Dyad in Mice

Pain accompanied by depressive symptoms is a common reason for seeking medical assistance, and many chronic pain patients experience comorbid depression. The brain-derived neurotrophic factor (BDNF) is a well-known neurotrophin expressed throughout the nervous system, playing a crucial role in neuronal growth and neuroplasticity. This study aimed to examine the effects of exercise on BDNF expression in the nervous system and reserpine (RSP)-induced pain-depression dyad. RSP (1 mg/kg) was subcutaneously administered once daily for three days in mice. The exercise was performed using a rota-rod tester for seven consecutive days following RSP administration. Pain responses were evaluated using von Frey filaments, and depression-like behaviors were assessed through forced swimming and open field tests. Immunofluorescence staining was performed to examine the changes in BDNF expression in the dorsal root ganglion (DRG), spinal cord, and hippocampus. Administration of RSP reduced mechanical paw withdrawal threshold, increased immobility time in the forced swimming test, and decreased movement in the open field test. The immunoreactivity of BDNF was increased in the DRG and spinal dorsal regions, and decreased in the hippocampus after RSP administration. Physical exercise significantly reduced the RSP-induced mechanical hypersensitivity and depression-like behaviors. In addition, exercise suppressed not only the increased expression of BDNF in the DRG and spinal dorsal regions but also the decreased expression of BDNF in the hippocampus induced by RSP administration. These findings suggest that repetitive exercise could serve as an effective and non-invasive treatment option for individuals experiencing both pain and depression by modulating BDNF expression.

An insight into crosstalk among multiple signalling pathways contributing to the pathophysiology of PTSD and depressive disorders

Post-traumatic stress disorder (PTSD) and depressive disorders represent two significant mental health challenges with substantial global prevalence. These are debilitating conditions characterized by persistent, often comorbid, symptoms that severely impact an individual's quality of life. Both PTSD and depressive disorders are often precipitated by exposure to traumatic events or chronic stress. The profound impact of PTSD and depressive disorders on individuals and society necessitates a comprehensive exploration of their shared and distinct pathophysiological features. Although the activation of the stress system is essential for maintaining homeostasis, the ability to recover from it after diminishing the threat stimulus is also equally important. However, little is known about the main reasons for individuals' differential susceptibility to external stressful stimuli. The solution to this question can be found by delving into the interplay of stress with the cognitive and emotional processing of traumatic incidents at the molecular level. Evidence suggests that dysregulation in these signalling cascades may contribute to the persistence and severity of PTSD and depressive symptoms. The treatment strategies available for this disorder are antidepressants, which have shown good efficiency in normalizing symptom severity; however, their efficacy is limited in most individuals. This calls for the exploration and development of innovative medications to address the treatment of PTSD. This review delves into the intricate crosstalk among multiple signalling pathways implicated in the development and manifestation of these mental health conditions. By unravelling the complexities of crosstalk among multiple signalling pathways, this review aims to contribute to the broader knowledge base, providing insights that could inform the development of targeted interventions for individuals grappling with the challenges of PTSD and depressive disorders.

Sex-controlled differences in sertraline and citalopram efficacies in major depressive disorder: a randomized, double-blind trial

To investigate the response to antidepressants while controlling for sex, which has been controversial, 92 outpatient males and females with major depressive disorder were assigned to sertraline (100 mg/day) or citalopram (40 mg/day) in two strata and were assessed using Hamilton depression rating scale (HDRS) scores and brain-derived neurotrophic factor (BDNF), interleukin (IL)-6 and cortisol serum levels in this 8-week, randomized, parallel-group, double-blind clinical trial. Data of 40 sertraline and 40 citalopram recipients with equal representation of males and females assigned to each medication were analyzed, while their baseline characteristics were not statistically different (P > 0.05). There were no significant differences between sertraline and citalopram recipients in outcome changes (P > 0.05), all of which indicated improvement, but a significant time-treatment-sex interaction effect in BDNF levels was observed (P = 0.035). Regarding this, subgroup analyses illustrated a significantly greater increase in male BDNF levels following sertraline treatment (P = 0.020) with a moderate to large effect size (Cohen's d = 0.76 and ). Significant associations were observed between percentage changes in IL-6 levels and BDNF levels in sertraline recipients (P = 0.033) and HDRS scores in citalopram recipients (P < 0.001). Sex was an effect modifier in BDNF alterations following sertraline and citalopram administration. Further large-scale, high-quality, long-term studies are recommended.

Chronic exposure to imipramine induces a switch from depression-like to mania-like behavior in female serotonin transporter knockout rats: Role of BDNF signaling in the infralimbic cortex

BACKGROUND

Bipolar disorder (BD) is a highly burdensome psychiatric disorder characterized by alternating states of mania and depression. A major challenge in the clinic is the switch from depression to mania, which is often observed in female BD patients during antidepressant treatment such as imipramine. However, the underlying neural basis is unclear.

METHODS

To investigate the potential neuronal pathways, serotonin transporter knockout (SERT KO) rats, an experimental model of female BD patients, were subjected to a battery of behavioral tests under chronic treatment of the antidepressant imipramine. In addition, the expression of brain-derived neurotrophic factor (BDNF) and its downstream signaling was examined in the prefrontal cortex.

RESULTS

Chronic exposure to imipramine reduced anxiety and sociability and problem-solving capacity, and increased thigmotaxis and day/night activity in all animals, but specifically in female SERT KO rats, compared to female wild-type (WT) rats. Further, we found an activation of BDNF-TrkB-Akt pathway signaling in the infralimbic, but not prelimbic, cortex after chronic imipramine treatment in SERT KO, but not WT, rats.

LIMITATIONS

Repeated testing behaviors could potentially affect the results. Additionally, the imipramine induced changes in behavior and in the BDNF system were measured in separate animals.

CONCLUSIONS

Our study indicates that female SERT KO rats, which mirror the female BD patients with the 5-HTTLPR s-allele, are at higher risk of a switch to mania-like behaviors under imipramine treatment. Activation of the BDNF-TrkB-Akt pathway in the infralimbic cortex might contribute to this phenotype, but causal evidence remains to be provided.

Ceftriaxone averts neuroinflammation and relieves depressive-like behaviors via GLT-1/TrkB signaling

The beneficial effect of a beta-lactam antibiotic, Ceftriaxone (CEF), to improve depressive-like symptoms has been documented previously, attributed to its modulation of glutamate neurotransmission. Here, we aimed to determine whether CEF could improve LPS-altered glutamatergic signaling associated with neuroinflammation-allied depression. To assess our goals, we established a neuroinflammation-allied depression mice model by injecting lipopolysaccharides (LPS), followed by behavioral and biochemical analysis. LPS-treated mice displayed depressive symptoms, neuroinflammation, dysregulated glutamate and its transporter (GLT-1) expression, altered expression of astrocyte reactive markers (GFAP, cxcl10, steap4, GBP2, and SRGN), and dysregulated BDNF/TrkB signaling. However, these changes were rescued by CEF treatment, as we found decreased neuroinflammation, relief of depression symptoms, and improved GLT-1 and BDNF/TrkB signaling upon CEF treatment. Moreover, GLT-1 and BDNF/TrkB regulation role of CEF was validated by K252a and DHK treatment. In summary, the anti-depressive effects of glutamate modulators, like CEF, are closely related to their anti-inflammatory role.

Targeting BDNF with acupuncture: A novel integrated strategy for diabetes and depression comorbidity

Diabetes and depression are common comorbid conditions that impose a substantial health burden. Acupuncture may effectively improve symptoms in patients with diabetes and depression, but the underlying mechanism remains unclear. Brain-derived neurotrophic factor (BDNF) may play a vital role in the effects of acupuncture on diabetes and depression comorbidity. This review summarizes the potential role of BDNF in acupuncture for diabetes and depression comorbidity. BDNF appears to exert its effects via the BDNF-TrkB-ERK-CREB signaling pathway. BDNF levels are reduced in diabetes and depression, and acupuncture may increase BDNF expression, improving symptoms and glycemic control. High-quality research is needed to validate the efficacy of acupuncture for diabetes and depression comorbidity. Randomized controlled trials and mechanistic studies should investigate the BDNF pathway and other potential mechanisms. Improved understanding of the links between diabetes, depression and acupuncture may enable targeted and individualized patient care. Earlier diagnosis and management of diabetes and depression comorbidity should also be a priority.

Effect of Ganglioside combined with pramexol in the treatment of Parkinson's disease and its effect on motor function

Background

This study was aimed to evaluate the efficacy of pramipexole combined with ganglioside for PD treatment and pramipexole monotherapy, so as to provide reference for clinical practice.

Methods

61 PD patients selected from June 2019 to December 2020 at our hospital were divided into two groups. The control group (n=31) was given dopasizide oral treatment, and the treatment group (n=30) was given ganglioside combined with pramipexole. The clinical efficacy, adverse reactions, motor function scores, UPDRS scores, PDQ-39 scale scores, TNF-a levels, and related serum factor levels were measured in this study.

Neurotrophin signalling in the human nervous system

This review focuses on neurotrophins and their tyrosine kinase receptors, with an emphasis on their relevance to the function and dysfunction in the human nervous system. It also deals with measurements of BDNF levels and highlights recent findings from our laboratory on TrkB and TrkC signalling in human neurons. These include ligand selectivity and Trk activation by neurotrophins and non-neurotrophin ligands. The ligand-induced down-regulation and re-activation of Trk receptors is also discussed.

Antidepressive mechanisms of rhynchophylline in mice with chronic unpredictable stress-induced depression

ETHNOPHARMACOLOGICAL RELEVANCE

Uncaria rhynchophylla ([Mi] Jack) (gouteng) exerts antidepressive effects. Rhynchophylline (RH), a major component of U. rhynchophylla, exerts similar pharmacological effects to those of gouteng. Thus, RH may have antidepressive effects.

AIM OF THE STUDY

To investigate the anti-depressive effects of RH in chronic unpredictable mild stress (CUMS)-induced depressive mice. The anti-depressive mechanism of RH determined by measuring the 5-HT levels, the expressions of cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in cortex and hippocampus.

MATERIALS AND METHODS

The behaviors of CUMS-induced depressive mice were measured using an open field test (OFT), forced swimming test (FST), and tail suspension test (TST). 5-HT levels were measured using an ELISA kits. The expressions of BDNF and CREB were determined using western blot test.

RESULTS

RH increased the frequency of rearing and grooming in the OFT and decreased the immobility time in the FST and TST. RH effectively increased the 5-HT level and BDNF and CREB expressions in the cortex and hippocampus.

CONCLUSION

Our findings indicate that the antidepressive mechanism of RH is related to increased levels of 5-HT from regulating CREB and BDNF expressions in cortex and hippocampus.

Biological effects of exposure to 2650 MHz electromagnetic radiation on the behavior, learning, and memory of mice

BACKGROUND

With the development of communication technology, the public is paying increasing attention to whether electromagnetic radiation is harmful to health. Mobile phone communication has entered the 5G era, and there are almost no reports on electromagnetic radiation at 2650 MHz. Therefore, it is necessary to evaluate the risk of adverse effects of 5G mobile phone EMR exposure on the human brain.

METHODS

Male animals were continuously exposed to 2650 MHz-EMR for 28 days with a whole-body averaged specific absorption rate (WBSAR) of 2.06 W/kg for 4 h per day. Mouse behavior was assessed using the open-field test (OFT), elevated-plus maze (EPM), and tail suspension test (TST). The Morris water maze (MWM), HE staining, and TUNEL staining were used to evaluate the spatial memory ability and pathological morphology of hippocampal dentate gyrus cells. Additionally, the expression levels of brain-derived neurotrophic factor (BDNF), aminobutyric acid (GABA), and glucocorticoid (GR) in the hippocampus were detected by western blotting and immunohistochemistry, while the corticosterone (CORT) level in serum was detected by ELISA.

RESULTS

In the OFT, the total distance traveled, central distance traveled, and residence time significantly decreased in the EMR exposure group (p < .05). In EPM, the percentage of the number of times to open the arm and the percentage of time to open the arm significantly decreased in the EMR exposure group. However, in the TST, the two groups had no significant difference in the 4-min immobility time. In the MWM, the escape latency of the EMR exposure group was shorter than that of the control group, with no significant difference. Furthermore, CORT levels in serum were significantly increased in the EMR exposure group (p < .05), while the expression of BDNF and GR proteins in the hippocampus was reduced (p < .05), but there was no significant difference in GABA expression.

CONCLUSIONS

Our results indicate that exposure to 2650 MHz-EMR (WBSAR: 2.06 W/kg, 28 days, 4 h per day) had no significant effect on the spatial memory ability of mice (in comparison to little effect). The exposure may be associated with anxiety-like behavior in mice but not related to depression-like behavior in mice.

The Melanocortin System: A Promising Target for the Development of New Antidepressant Drugs

Major depression is one of the most prevalent mental disorders, causing significant human suffering and socioeconomic loss. Since conventional antidepressants are not sufficiently effective, there is an urgent need to develop new antidepressant medications. Despite marked advances in the neurobiology of depression, the etiology and pathophysiology of this disease remain poorly understood. Classical and newer hypotheses of depression suggest that an imbalance of brain monoamines, dysregulation of the hypothalamic-pituitary-adrenal axis (HPAA) and immune system, or impaired hippocampal neurogenesis and neurotrophic factors pathways are cause of depression. It is assumed that conventional antidepressants improve these closely related disturbances. The purpose of this review was to discuss the possibility of affecting these disturbances by targeting the melanocortin system, which includes adrenocorticotropic hormone-activated receptors and their peptide ligands (melanocortins). The melanocortin system is involved in the regulation of various processes in the brain and periphery. Melanocortins, including peripherally administered non-corticotropic agonists, regulate HPAA activity, exhibit anti-inflammatory effects, stimulate the levels of neurotrophic factors, and enhance hippocampal neurogenesis and neurotransmission. Therefore, endogenous melanocortins and their analogs are able to complexly affect the functioning of those body’s systems that are closely related to depression and the effects of antidepressants, thereby demonstrating a promising antidepressant potential.

Gut microbiota: A new target for traditional Chinese medicine in the treatment of depression

ETHNIC PHARMACOLOGICAL RELEVANCE

The causes of depression are complex. Many factors are involved in its pathogenesis, including the individual's biological and social environment. Although numerous studies have reported that the gut microbiota plays a significant role in depression, drugs that regulate the gut microbiota to treat depression have not yet been comprehensively reviewed. At the same time, more and more attention has been paid to the characteristics of traditional Chinese medicine (TCM) in improving depression by regulating gut microbiota. In ancient times, fecal microbiota transplantation was recorded in TCM for the treatment of severe diseases. There are also records in Chinese ancient books about the use of TCM to adjust gut microbiota to treat diseases, which has opened up a unique research field in TCM. Therefore, this article focuses on the pharmacological effects, targets, and mechanisms of TCM in improving depression by mediating the influence of gut microbiota.

AIM OF THIS REVIEW

To summarize the role the gut microbiota plays in depression, highlight potential regulatory targets, and elucidate the anti-depression mechanisms of TCMs through regulation of the gut microbiota.

METHODS

A systematic review of 256 clinical trials and pharmaceutical studies published until June 2022 was conducted in eight electronic databases (Web of Science, PubMed, SciFinder, Research Gate, ScienceDirect, Google Scholar, Scopus, and China Knowledge Infrastructure), according to the implemented PRISMA criteria, using the search terms "traditional Chinese medicine," "depression," and "gut microbiota."

RESULTS

Numerous studies reported the effects of different gut bacteria on depression and that antidepressants work through the gut microbiota. TCM preparations based on compound Chinese medicine, the Chinese Materia Medica, and major bioactive components exerted antidepressant-like effects by improving levels of neurotransmitters, short-chain fatty acids, brain-derived neurotrophic factor, kynurenine, and cytokines via regulation of the gut microbiota.

CONCLUSION

This review summarized the anti-depression effects of TCM on the gut microbiota, providing evidence that TCMs are safe and effective in the treatment of depression and may provide a new therapeutic approach.

Peripheral Regulation of Central Brain-Derived Neurotrophic Factor Expression through the Vagus Nerve

The brain-derived neurotrophic factor (BDNF) is an extensively studied neurotrophin es sential for both developing the brain and maintaining adult brain function. In the adult hippocampus, BDNF is critical for maintaining adult neurogenesis. Adult hippocampal neurogenesis is involved not only in memory formation and learning ability, but also mood regulation and stress responses. Accordingly, decreased levels of BDNF, accompanied by low levels of adult neurogenesis, occurs in brains of older adults with impaired cognitive function and in those of patients with major depression disorder. Therefore, elucidating the mechanisms that maintain hippocampal BDNF levels is biologically and clinically important. It has been revealed that signalling from peripheral tissues contribute to the regulation of BDNF expression in the brain across the blood-brain barrier. Moreover, recent studies indicated evidence that neuronal pathways can also be a mechanism by which peripheral tissues signal to the brain for the regulation of BDNF expression. In this review, we give an overview of the current status in the regulation of central BDNF expression by peripheral signalling, with a special interest in the regulation of hippocampal BDNF levels by signals via the vagus nerve. Finally, we discuss the relationship between signalling from peripheral tissues and age-associated control of central BDNF expression.

Effect of vitamin K2 administration on depression status in patients with polycystic ovary syndrome: a randomized clinical trial

Background

Patients with Polycystic ovary syndrome (PCOS) are predisposed to the development of several mental comorbidities such as depression. According to several studies, PCOS can be managed by improving insulin sensitivity. The insulin-sensitizing effect of vitamin K has been reported in recent studies. Therefore, in the current trial, we assessed the effect of administrating vitamin K2 (Menaquinone-7) on depression status in women afflicted with PCOS.

Methods

Eighty-four PCOS women were allocated into the intervention and comparison groups; the intervention group (n = 42) administered 90 µg/day Menaquinone-7, and the comparison group (n = 42) consumed placebo capsules (containing avesil) for 8 weeks. In this randomized, double blind, placebo-controlled clinical trial, depression status was measured by BECK depression inventory-II (BDI-II) before and after 8 weeks of intervention.

Results

Consumption of Menaquinone-7 in comparison with the placebo capsules significantly improved depression status (P = 0.012).

Conclusion

This clinical study reported the advantageous effect of Menaquinone-7 administration on depression status in PCOS patients.

Trial registration The present study was registered at http://www.IRCT.ir on 06/06/2018 (registration number: IRCT20170916036204N5).

Alcohol Withdrawal and the Associated Mood Disorders-A Review

Recreational use of alcohol is a social norm in many communities worldwide. Alcohol use in moderation brings pleasure and may protect the cardiovascular system. However, excessive alcohol consumption or alcohol abuse are detrimental to one's health. Three million deaths due to excessive alcohol consumption were reported by the World Health Organization. Emerging evidence also revealed the danger of moderate consumption, which includes the increased risk to cancer. Alcohol abuse and periods of withdrawal have been linked to depression and anxiety. Here, we present the effects of alcohol consumption (acute and chronic) on important brain structures-the frontal lobe, the temporal lobe, the limbic system, and the cerebellum. Apart from this, we also present the link between alcohol abuse and withdrawal and mood disorders in this review, thus drawing a link to oxidative stress. In addition, we also discuss the positive impacts of some pharmacotherapies used. Due to the ever-rising demands of life, the cycle between alcohol abuse, withdrawal, and mood disorders may be a never-ending cycle of destruction. Hence, through this review, we hope that we can emphasise the importance and urgency of managing this issue with the appropriate approaches.

BDNF as a Mediator of Antidepressant Response: Recent Advances and Lifestyle Interactions

Conventional antidepressants are widely employed in several psychiatric and neurologic disorders, yet the mechanisms underlying their delayed and partial therapeutic effects are only gradually being understood. This narrative review provides an up-to-date overview of the interplay between antidepressant treatment and Brain-Derived Neurotrophic Factor (BDNF) signaling. In addition, the impact of nutritional, environmental and physiological factors on BDNF and the antidepressant response is outlined. This review underlines the necessity to include information on lifestyle choices in testing and developing antidepressant treatments in the future.

BDNF receptor TrkB as the mediator of the antidepressant drug action

Brain-derived neurotrophic factor (BDNF) signaling through its receptor TrkB has for a long time been recognized as a critical mediator of the antidepressant drug action, but BDNF signaling has been considered to be activated indirectly through the action of typical and rapid-acting antidepressants through monoamine transporters and glutamate NMDA receptors, respectively. However, recent findings demonstrate that both typical and the fast-acting antidepressants directly bind to TrkB and thereby allosterically potentiate BDNF signaling, suggesting that TrkB is the direct target for antidepressant drugs. Increased TrkB signaling particularly in the parvalbumin-expressing interneurons orchestrates iPlasticity, a state of juvenile-like enhanced plasticity in the adult brain. iPlasticity sensitizes neuronal networks to environmental influences, enabling rewiring of networks miswired by adverse experiences. These findings have dramatically changed the position of TrkB in the antidepressant effects and they propose a new end-to-end model of the antidepressant drug action. This model emphasizes the enabling role of antidepressant treatment and the active participation of the patient in the process of recovery from mood disorders.

Various BDNF administrations attenuate SPS-induced anxiety-like behaviors

Post-traumatic stress disorder (PTSD) has become epidemic following severely stressful incidents. Previous studies have shown that brain-derived neurotrophic factor (BDNF) has anxiolytic effects on various anxiety or depression disorders including PTSD. However, the detailed mechanisms of BDNF for treating PTSD were rarely investigated. In the current study, single-prolonged stress (SPS) was used as an animal model recapitulating specific aspects for a PTSD-like phenotype. The effects of BDNF on SPS-induced anxiety-like behaviors were investigated. We showed that the levels of BDNF in the cerebro-spinal fluid (CSF) were significantly reduced after the rats experienced SPS. The SPS-induced reductions of percentages of time spent in the central area to total time in the open field test, were dose-dependently mitigated after BDNF intracerebroventricular (i.c.v.) injections. BDNF i.c.v. administration also dose-dependently increased the preference of the light box in the light-dark box test. Both expressions of tyrosine kinase receptor B (TrkB) protein and mRNA in the prefrontal cortex (PFC) and amygdala were significantly increased after SPS challenges. BDNF i.c.v. administration attenuated these compensatory increases of TrkB. At last, the anxiolytic effects of BDNF on SPS model were also observed by using other two injection methods. These results inspired us to study that different administrations of BDNF were used in patients with PTSD in the future, in-depthly.

Encore: Behavioural animal models of stress, depression and mood disorders

Animal studies over the past two decades have led to extensive advances in our understanding of pathogenesis of depressive and mood disorders. Among these, rodent behavioural models proved to be of highest informative value. Here, we present a comprehensive overview of the most popular behavioural models with respect to physiological, circuit, and molecular biological correlates. Behavioural stress paradigms and behavioural tests are assessed in terms of outcomes, strengths, weaknesses, and translational value, especially in the domain of pharmacological studies.

The Role of Brain-Derived Neurotrophic Factor Signaling in Central Nervous System Disease Pathogenesis

Recent studies have found abnormal levels of brain-derived neurotrophic factor (BDNF) in a variety of central nervous system (CNS) diseases (e.g., stroke, depression, anxiety, Alzheimer's disease, and Parkinson's disease). This suggests that BDNF may be involved in the pathogenesis of these diseases. Moreover, regulating BDNF signaling may represent a potential treatment for such diseases. With reference to recent research papers in related fields, this article reviews the production and regulation of BDNF in CNS and the role of BDNF signaling disorders in these diseases. A brief introduction of the clinical application status of BDNF is also provided.

Pro-cognitive effect of acute imipramine administration correlates with direct interaction of BDNF with its receptor, Trkβ

Given the important role of brain-derived neurotrophic factor (BDNF)-mediated Trkβ signalling in the mechanism of action of antidepressants (ADs), we examined ligand-receptor interactions in the rat cingulate cortex using a proximity ligation assay (PLA) in response to acute and repeated administration of imipramine (IMI), followed by various drug-free periods. Both the acute and chronic administration of IMI increased the BDNF-Trkβ interaction observed 3 h after drug administration. Withdrawal of IMI for 72 h or 7 days did not alter BDNF-Trkβ interaction. A significant reduction in this interaction after chronic IMI administration followed by 21 drug-free days was observed, but it returned to the control value when a new dose of IMI was given after this time. The level of mRNA encoding BDNF or Trkβ did not change in the experimental groups of animals, so one can conclude that alterations in the BDNF-Trkβ interaction depend not on acute vs. repeated treatment with IMI but on the presence of the drug in the body. This effect correlates well with the strong pro-cognitive effect of acute IMI, assessed by the novel object recognition (NOR) test.

Vitamin D3 suppresses astrocyte activation and ameliorates coal dust-induced mood disorders in mice

BACKGROUND

Pneumoconiosis patients exhibit significantly more anxiety and depression than healthy individuals. However, the mechanism of coal dust-induced anxiety and depression remains unclear.

METHODS

A pneumoconiosis mouse model with anxiety- and depression-like behaviors were established after 28 days of exposure to coal dust. Vitamin D3 treatment (1200 IU/kg/week) was administered intraperitoneally for 3 months starting from the first coal exposure. Tail suspension test (TST), open field test (OFT), and elevated plus-maze (EPM) test were used to assess anxiety- and depression-like behaviors. Theserum concentration of 25(OH)D₃ and fibrillary acid protein (GFAP) expression were determined. In addition, the morphology and distribution of GFAP and neurogenic differentiation factor1 expression (NeuroD1) in different cerebral hippocampus were observed.

RESULTS

In coal dust-exposed mice, immobility time decreased in OFT and increased in TST,and the frequency of entering the open arm decreased in the EPM compared with the control mice. Coal dust increased hippocampal GFAP expression and astrocyte activation and reduced neurogenic differentiation factor1 expression (NeuroD1). In addition, Vitamin D3 significantly alleviated anxiety- and depressive-like behaviors in TST and EPM test, decreased GFAP expression level, modified hippocampal astrocyte activation pattern, and advanced brain-derived neurotrophic factor (BDNF) distribution and expression in CA1 and CA3 of the hippocampus.

CONCLUSIONS

Taken together, our results suggest that, by inhibiting the over-activation of astrocytes and increasing BDNF and neuron protection, vitamin D treatment ameliorates coal-dust-induced depressive and anxiety-like behavior, which is the first evidence that vitamin D may be a new approach for treating mood disorders caused by particulate matter.

Neuroimmune crosstalk through brain-derived neurotrophic factor and its precursor pro-BDNF: New insights into mood disorders

Mood disorders are the most common mental disorders, affecting approximately 350 million people globally. Recent studies have shown that neuroimmune interaction regulates mood disorders. Brain-derived neurotrophic factor (BDNF) and its precursor pro-BDNF, are involved in the neuroimmune crosstalk during the development of mood disorders. BDNF is implicated in the pathophysiology of psychiatric and neurological disorders especially in antidepressant pharmacotherapy. In this review, we describe the functions of BDNF/pro-BDNF signaling in the central nervous system in the context of mood disorders. In addition, we summarize the developments for BDNF and pro-BDNF functions in mood disorders. This review aims to provide new insights into the impact of neuroimmune interaction on mood disorders and reveal a new basis for further development of diagnostic targets and mood disorders.

Fluoxetine acts concomitantly on dorsal and ventral hippocampus to Trk-dependently modulate the extinction of fear memory

BACKGROUND

Hippocampus can be divided along its longitudinal axis into dorsal and ventral parts, which play different roles in modulating the behavioral responses to stress. However, it is not clear whether the hippocampal subregions could also differently modulate the effect of antidepressant drugs. Since fluoxetine (FLX) effect on extinction of aversive memory is well known to depend on hippocampal BDNF levels, we hypothesized that the hippocampal subregions might play different roles in fluoxetine efficacy in decreasing fear response.

METHOD

Wistar rats were fear-cued conditioned and treated chronically with FLX to subsequently investigate their extinction memory. BDNF levels were assessed separately in the dorsal (dHC) and ventral (vHC) hippocampus in animals chronically treated with FLX. An independent group received K252a (a functional Trk blocker) infusion into the dHC or vHC to assay its interaction with FLX treatment along the fear response. Next, BDNF was directly infused into either the dHC or vHC to the behavior be compared with those induced by chronic FLX treatment. Finally, FLX effect on c-Fos expression was evaluated also considering the dHC and vHC apart, along with subareas of amygdala and medial prefrontal cortex.

RESULTS

BDNF levels were increased in the vHC after acute FLX, and in the dHC after chronic FLX treatment. FLX effect on fear response was blocked by K252a administration into either dHC or vHC, after the extinction protocol. BDNF administration into the dHC increased fear response, however its administration into the vHC induced an opposite effect. Besides, a negative correlation between the fear response and c-Fos expression in the dHC CA3/CA1 and vHC CA1/DG was observed after chronic FLX treatment.

CONCLUSION

Both dHC and vHC are essential for the Trk-dependent effect of FLX on extinction memory, although a discrepancy in the fear response was observed with the infusion of BDNF into the dHC or vHC.

Probiotic supplementation alleviates absence seizures and anxiety- and depression-like behavior in WAG/Rij rat by increasing neurotrophic factors and decreasing proinflammatory cytokines

AIM

Epilepsy is one of the most common chronic brain disorders that affect millions of people worldwide. In the present study, we investigated the effects of probiotic supplementation on absence epilepsy and anxiety-and depression-like behavior in WAG/Rij rats.

MATERIAL AND METHOD

Fourteen male WAG/Rij rats (absence-epileptic) and seven male Wistar rats (nonepileptic) were used. The effects of probiotic VSL#3 (12.86 bn living bacteria/kg/day for 30 day/gavage) on absence seizures, and related psychiatric comorbidities were evaluated in WAG/Rij rats. Anxiety-like behavior was evaluated by the open-field test and depression-like behavior by the forced swimming test. In addition, the brain tissues of rats were evaluated histopathologically for nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], SRY sex-determining region Y-box 2 [SOX2] and biochemically for nitric oxide [NO], tumor necrosis factor-alpha [TNF-α] ,and Interleukin-6 [IL-6].

RESULTS

Compared to Wistar rats, WAG/Rij rats exhibited anxiety- and depression-like behavior, and had lower BDNF, NGF and SOX2 immunoreactivity, and higher TNF-α, IL-6 levels in brain tissue. VSL#3 supplementation reduced the duration and number of spike-wave discharges (SWDs) and exhibited anxiolytic or anti-depressive effect. VSL#3 supplement also increased the NGF immunoreactivity while decreasing IL-6, TNF-α and NO levels in WAG/Rij rat brain.

CONCLUSION

The findings of the present study showed that neurotrophins, SOX2 deficiency, and pro-inflammatory cytokines may play a role in the pathogenesis of absence epilepsy. Our data support the hypothesis that the probiotics have anti-inflammatory effect. The present study is the first to show the positive effects of probiotic bacteria on absence seizures and anxiety- and depression-like behavior.

The neuropeptide cycloprolylglycine produces antidepressant-like effect and enhances BDNF gene expression in the mice cortex

BACKGROUND

Cycloprolylglycine (CPG) is an endogenous dipeptide with a wide range of psychotropic activity and putative therapeutic potential for depression. A small but growing body of data suggests that antidepressant-like effect of CPG is associated with neuroplastic changes in the brain or 5-HT system modulation. However, the mechanisms of the dipeptide action remain elusive.

AIMS

Here, we characterize the effects of chronic CPG administration on behavior and genes expression of antidepressants sensitive catalepsy (ASC) mice strain, characterized by depressive-like behavior.

METHODS

ASC mice were injected with saline, fluoxetine (10 mg/kg/day), or CPG (1 and 2 mg/kg/day) during 2 weeks. Behavior was studied using the open field test, novel object test, elevated plus maze test, forced swim test, and tail suspension test (TST). The expressions of genes coding BDNF, CREB, 5-HT_1A and 5-HT_2A receptors, TPH2, and SERT in the brain were measured with quantitative real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Chronic intraperitoneal administration of 1 and 2 mg/kg of CPG revealed the significant antidepressant-like effect by decreasing immobility time in the TST. At the same time, CPG did not negatively affect locomotor activity, cognition, or anxiety. In the real-time quantitative polymerase chain reaction (PCR) assay, chronic CPG treatment (2 mg/kg for 14 days) increased Bdnf mRNA level in the frontal cortex.

CONCLUSIONS

Our findings extend the evidence for the effectiveness of CPG to reduce depressive-like behaviors. The antidepressant-like effect of CPG is mediated, as least in part, by BDNF-dependent mechanism. The exact mechanism remains to be elucidated, and further studies are warranted.

Brain-derived neurotrophic factor and inflammation in depression: Pathogenic partners in crime?

Major depressive disorder is a debilitating disorder affecting millions of people each year. Brain-derived neurotrophic factor (BDNF) and inflammation are two prominent biologic risk factors in the pathogenesis of depression that have received considerable attention. Many clinical and animal studies have highlighted associations between low levels of BDNF or high levels of inflammatory markers and the development of behavioral symptoms of depression. However, less is known about potential interaction between BDNF and inflammation, particularly within the central nervous system. Emerging evidence suggests that there is bidirectional regulation between these factors with important implications for the development of depressive symptoms and anti-depressant response. Elevated levels of inflammatory mediators have been shown to reduce expression of BDNF, and BDNF may play an important negative regulatory role on inflammation within the brain. Understanding this interaction more fully within the context of neuropsychiatric disease is important for both developing a fuller understanding of biological pathogenesis of depression and for identifying novel therapeutic opportunities. Here we review these two prominent risk factors for depression with a particular focus on pathogenic implications of their interaction.

BDNF signaling in context: From synaptic regulation to psychiatric disorders

Brain-derived neurotrophic factor (BDNF) is a neuropeptide that plays numerous important roles in synaptic development and plasticity. While its importance in fundamental physiology is well established, studies of BDNF often produce conflicting and unclear results, and the scope of existing research makes the prospect of setting future directions daunting. In this review, we examine the importance of spatial and temporal factors on BDNF activity, particularly in processes such as synaptogenesis, Hebbian plasticity, homeostatic plasticity, and the treatment of psychiatric disorders. Understanding the fundamental physiology of when, where, and how BDNF acts and new approaches to control BDNF signaling in time and space can contribute to improved therapeutics and patient outcomes.

Analysis of Antidepressant-like Effects and Action Mechanisms of GSB-106, a Small Molecule, Affecting the TrkB Signaling

Induction of BDNF-TrkB signaling is associated with the action mechanisms of conventional and fast-acting antidepressants. GSB-106, developed as a small dimeric dipeptide mimetic of BDNF, was previously shown to produce antidepressant-like effects in the mouse Porsolt test, tail suspension test, Nomura water wheel test, in the chronic social defeat stress model and in the inflammation-induced model of depression. In the present study, we evaluated the effect of chronic per os administration of GSB-106 to Balb/c mice under unpredictable chronic mild stress (UCMS). It was observed for the first time that long term GSB-106 treatment (1 mg/kg, 26 days) during ongoing UCMS procedure ameliorated the depressive-like behaviors in mice as indicated by the Porsolt test. In addition, chronic per os administration of GSB-106 resulted in an increase in BDNF levels, which were found to be decreased in the prefrontal cortex and hippocampus of mice after UCMS. Furthermore, prolonged GSB-106 treatment was accompanied by an increase in the content of pTrkB^706/707 in the prefrontal cortex and by a pronounced increase in the level of pTrkB⁸¹⁶ in both studied brain structures of mice subjected to UCMS procedure. In summary, the present data show that chronic GSB-106 treatment produces an antidepressant-like effect in the unpredictable chronic mild stress model, which is likely to be associated with the regulation of the BDNF-TrkB signaling.

Psychedelics and Other Psychoplastogens for Treating Mental Illness

Psychedelics have inspired new hope for treating brain disorders, as they seem to be unlike any treatments currently available. Not only do they produce sustained therapeutic effects following a single administration, they also appear to have broad therapeutic potential, demonstrating efficacy for treating depression, post-traumatic stress disorder (PTSD), anxiety disorders, substance abuse disorder, and alcohol use disorder, among others. Psychedelics belong to a more general class of compounds known as psychoplastogens, which robustly promote structural and functional neural plasticity in key circuits relevant to brain health. Here we discuss the importance of structural plasticity in the treatment of neuropsychiatric diseases, as well as the evidence demonstrating that psychedelics are among the most effective chemical modulators of neural plasticity studied to date. Furthermore, we provide a theoretical framework with the potential to explain why psychedelic compounds produce long-lasting therapeutic effects across a wide range of brain disorders. Despite their promise as broadly efficacious neurotherapeutics, there are several issues associated with psychedelic-based medicines that drastically limit their clinical scalability. We discuss these challenges and how they might be overcome through the development of non-hallucinogenic psychoplastogens. The clinical use of psychedelics and other psychoplastogenic compounds marks a paradigm shift in neuropsychiatry toward therapeutic approaches relying on the selective modulation of neural circuits with small molecule drugs. Psychoplastogen research brings us one step closer to actually curing mental illness by rectifying the underlying pathophysiology of disorders like depression, moving beyond simply treating disease symptoms. However, determining how to most effectively deploy psychoplastogenic medicines at scale will be an important consideration as the field moves forward.

Hijacking Dorsal Raphe to Improve Metabolism and Depression-Like Behaviors via BDNF Gene Transfer in Mice

Moods and metabolism modulate each other. High comorbidity of depression and metabolic disorders, such as diabetes and obesity, poses a great challenge to treat such conditions. Here we report the therapeutic efficacy of brain-derived neurotrophic factor (BDNF) by gene transfer in the dorsal raphe nucleus (DRN) in a chronic unpredictable mild stress model (CUMS) of depression and models of diabetes and obesity. In CUMS, BDNF-expressing mice displayed antidepressant- and anxiolytic-like behaviors, which are associated with augmented serotonergic activity. Both in the diet-induced obesity model (DIO) and in db/db mice, BDNF ameliorated obesity and diabetes, which may be mediated by enhanced sympathetic activity not involving DRN serotonin. Chronic activation of DRN neurons via chemogenetic tools produced similar effects as BDNF in DIO mice. These results established the DRN as a key nexus in regulating depression-like behaviors and metabolism, which can be exploited to combat comorbid depression and metabolic disorders via BDNF gene transfer.

Leptin regulates exon-specific transcription of the Bdnf gene via epigenetic modifications mediated by an AKT/p300 HAT cascade

Leptin is an adipocyte-derived hormone with pleiotropic functions affecting appetite and mood. While leptin's role in the regulation of appetite has been extensively studied in hypothalamic neurons, its function in the hippocampus, where it regulates mood-related behaviors, is poorly understood. Here, we show that the leptin receptor (LepRb) colocalizes with brain-derived neurotrophic factor (BDNF), a key player in the pathophysiology of major depression and the action of antidepressants, in the dentate gyrus of the hippocampus. Leptin treatment increases, whereas deficiency of leptin or leptin receptors decreases, total Bdnf mRNA levels, with distinct expression profiles of specific exons, in the hippocampus. Epigenetic analyses reveal that histone modifications, but not DNA methylation, underlie exon-specific transcription of the Bdnf gene induced by leptin. This is mediated by stimulation of AKT signaling, which in turn activates histone acetyltransferase p300 (p300 HAT), leading to changes in histone H3 acetylation and methylation at specific Bdnf promoters. Furthermore, deletion of Bdnf in the dentate gyrus, or specifically in LepRb-expressing neurons, abolishes the antidepressant-like effects of leptin. These findings indicate that leptin, acting via an AKT-p300 HAT epigenetic cascade, induces exon-specific Bdnf expression, which in turn is indispensable for leptin-induced antidepressant-like effects.

The Periaqueductal Gray and Its Extended Participation in Drug Addiction Phenomena

The periaqueductal gray (PAG) is a complex mesencephalic structure involved in the integration and execution of active and passive self-protective behaviors against imminent threats, such as immobility or flight from a predator. PAG activity is also associated with the integration of responses against physical discomfort (e.g., anxiety, fear, pain, and disgust) which occurs prior an imminent attack, but also during withdrawal from drugs such as morphine and cocaine. The PAG sends and receives projections to and from other well-documented nuclei linked to the phenomenon of drug addiction including: (i) the ventral tegmental area; (ii) extended amygdala; (iii) medial prefrontal cortex; (iv) pontine nucleus; (v) bed nucleus of the stria terminalis; and (vi) hypothalamus. Preclinical models have suggested that the PAG contributes to the modulation of anxiety, fear, and nociception (all of which may produce physical discomfort) linked with chronic exposure to drugs of abuse. Withdrawal produced by the major pharmacological classes of drugs of abuse is mediated through actions that include participation of the PAG. In support of this, there is evidence of functional, pharmacological, molecular. And/or genetic alterations in the PAG during the impulsive/compulsive intake or withdrawal from a drug. Due to its small size, it is difficult to assess the anatomical participation of the PAG when using classical neuroimaging techniques, so its physiopathology in drug addiction has been underestimated and poorly documented. In this theoretical review, we discuss the involvement of the PAG in drug addiction mainly via its role as an integrator of responses to the physical discomfort associated with drug withdrawal.

Brain-Derived Neurotrophic Factor Signaling in Depression and Antidepressant Action

Neurotrophic factors, particularly BDNF (brain-derived neurotrophic factor), have been associated with depression and antidepressant drug action. A variety of preclinical and clinical studies have implicated impaired BDNF signaling through its receptor TrkB (neurotrophic receptor tyrosine kinase 2) in the pathophysiology of mood disorders, but many of the initial findings have not been fully supported by more recent meta-analyses, and more both basic and clinical research is needed. In contrast, increased expression and signaling of BDNF has been repeatedly implicated in the mechanisms of both typical and rapid-acting antidepressant drugs, and recent findings have started to elucidate the mechanisms through which antidepressants regulate BDNF signaling. BDNF is a critical regulator of various types of neuronal plasticities in the brain, and plasticity has increasingly been connected with antidepressant action. Although some equivocal data exist, the hypothesis of a connection between neurotrophic factors and neuronal plasticity with mood disorders and antidepressant action has recently been further strengthened by converging evidence from a variety of more recent data reviewed here.

Effect of Electroacupuncture at Siguan Acupoints on Expression of BDNF and TrkB Proteins in the Hippocampus of Post-Stroke Depression Rats

To study the effect of electroacupuncture at the Siguan acupoints on the expression of hippocampal brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB) in post-stroke depression (PSD) rats, in order to explore its possible mechanism Fifty specific pathogen-free (SPF)-grade adult male Sprague-Dawley (SD) rats were randomly divided into a blank group, stroke group, PSD group, Siguan acupoint group and fluoxetine group according to the random number method. PSD rats were modeled with middle cerebral artery occlusion combined with chronic unpredictable mild stress. After successful modeling, electroacupuncture was applied to Siguan acupoints for a total of 21 days at 30 min/session/day. The rats in the fluoxetine group were fed intragastrically according to body weight, once a day, for a total of 21 days. The rats in each group were bound and intragastrically administered distilled water every day. The depressive behavior of rats was measured according to the horizontal and vertical scores of the open field test and the sucrose water consumption, and the changes in the number of BDNF- and TrkB-positive cells in the hippocampus of rats were observed by immunohistochemistry. After modeling, the behavioral indicators and the numbers of BDNF- and TrkB-positive cells in each model group were significantly lower than those in the blank group (P < 0.01). After treatment, the behavioral indicators and the numbers of BDNF- and TrkB-positive cells in the Siguan acupoint group and fluoxetine group were significantly higher than that in the PSD group (P < 0.01). During the treatment, the horizontal and vertical scores of the Siguan acupoint group were significantly increased on the seventh day of treatment, and the difference was statistically significant when compared with the PSD group (P < 0.05). The sucrose water consumption was significantly increased on the 14th day of treatment, and the difference was significant when compared with the PSD group (P < 0.05), both of which were earlier than that in the fluoxetine group. During the treatment, there was no significant difference between the two groups (P > 0.05). Electroacupuncture at Siguan acupoints has the same antidepressant effect as fluoxetine, and is more effective than fluoxetine in relieving depression in PSD rats. Its mechanism may be related to the activation of the expression of BDNF and its receptor TrkB.

Antidepressant-like effects of acupuncture via modulation of corticosterone, sex hormones, and hippocampal BDNF expression in male rats

BACKGROUND

Post-weaning social isolated rodents exhibit pathophysiological changes associated with depression including adrenal axis hyperactivity, gonadal hormone level disturbances, molecular alterations in hippocampus, and immobility behavior in the forced swimming test (FST). Although acupuncture by absorbable thread implantation (acu-catgut, AC) elicits antidepressant-like effects in social isolated rats, AC effects on neuroendocrine and hippocampal molecular alterations have been less characterized.

OBJECTIVE

To investigate the participation of gonadal hormones, corticosterone, and brain-derived neurotrophic factor (BDNF) hippocampal expression, on the AC antidepressant-like effects in social isolated male rats.

METHODS

Sprague-Dawley male rats were raised in social isolation (SI) or standard conditions, for 11 weeks. AC (on Baihui (Du20), Yintang (E X-HN3), Shenshu (BL 23), Pishu (BL 20), Ganshu (BL 18), Xinshu (BL 15) and Guanyuan (Ren 4)), or Sham-AC (puncturing of acupoints without embedding the thread), was applied during the last three weeks of isolation period. Rats were evaluated in the FST; hormones plasmatic levels and hippocampal BDNF content were quantified by ELISA and Western blotting, respectively.

RESULTS

Social isolated rats showed more immobility in the FST and had lower testosterone and estradiol levels, higher corticosterone levels, and reduced hippocampal BDNF content than controls. BDNF level in hippocampus inversely correlated to depression-like behavior. AC but not sham-AC normalized immobility behavior, steroid hormone levels, and BDNF content, as in rats raised in a social environment.

CONCLUSIONS

AC antidepressant effect could be related to an improvement of hippocampal BDNF protein expression, as well as corticosterone and sex hormones disturbances associated with prolonged exposure to stress caused by social isolation. Present findings have implications for depression treatment in individuals early exposed to stress.

The (Poly)Pharmacology of Cannabidiol in Neurological and Neuropsychiatric Disorders: Molecular Mechanisms and Targets

Cannabidiol (CBD), the major nonpsychoactive Cannabis constituent, has been proposed for the treatment of a wide panel of neurological and neuropsychiatric disorders, including anxiety, schizophrenia, epilepsy and drug addiction due to the ability of its versatile scaffold to interact with diverse molecular targets that are not restricted to the endocannabinoid system. Albeit the molecular mechanisms responsible for the therapeutic effects of CBD have yet to be fully elucidated, many efforts have been devoted in the last decades to shed light on its complex pharmacological profile. In particular, an ever-increasing number of molecular targets linked to those disorders have been identified for this phytocannabinoid, along with the modulatory effects of CBD on their cascade signaling. In this view, here we will try to provide a comprehensive and up-to-date overview of the molecular basis underlying the therapeutic effects of CBD involved in the treatment of neurological and neuropsychiatric disorders.

Remedial effects of caffeine against depressive-like behaviour in mice by modulation of neuroinflammation and BDNF

Objective: Caffeine (CAF) is one of the most commonly consumed nutritional stimulant in beverages. Interestingly, CAF produces varied effects in a dose-dependent manner, and that makes it one of the most controversial nutritional ingredients. Various studies have linked CAF consumption and reduced risk of depressive disorders. The aim of this study was to investigate the effect of CAF on lipopolysaccharide (LPS)-induced neuroinflammation and depressive-like behaviour.Methods: C57BL/6J male mice were divided into four groups consisting of saline (SAL), LPS, CAF and Imipramine (IMI). Animals were pretreated orally with CAF (10 mg/kg) and IMI (10 mg/kg) for 14 days once daily and all groups except SAL were challenged with LPS (0.83 mg/kg) intraperitoneally on day 14.Results: LPS produced a biphasic behavioural response with a significantly high immobility time and weight loss after 24 h. The brain cytokines (TNF-α, IL-6, IL-1β, and IFN-γ) levels were remarkably high, along with increased lipid peroxidation and reduced Brain Derived Neurotrophic Factor (BDNF). These biochemical and behavioural changes were significantly alleviated by CAF and IMI chronic treatment.Conclusion: The results of this study implicate that mild-moderate consumption of CAF could impart anti-inflammatory properties under neuroinflammatory conditions by modulating the cytokine and neurotrophic mechanisms.

Effects of Two Months of Very Low Carbohydrate Ketogenic Diet on Body Composition, Muscle Strength, Muscle Area, and Blood Parameters in Competitive Natural Body Builders

Background: Ketogenic diet (KD) is a nutritional approach that restricts daily carbohydrates, replacing most of the reduced energy with fat, while maintaining an adequate quantity of protein. Despite the widespread use of KD in weight loss in athletes, there are still many concerns about its use in sports requiring muscle mass accrual. Thus, the present study sought to investigate the influence of a KD in competitive natural body builders. Methods: Nineteen volunteers (27.4 ± 10.5 years) were randomly assigned to ketogenic diet (KD) or to a western diet (WD). Body composition, muscle strength and basal metabolic rate were measured before and after two months of intervention. Standard blood biochemistry, testosterone, IGF-1, brain-derived neurotrophic factor (BDNF) and inflammatory cytokines (IL6, IL1β, TNFα) were also measured. Results: Body fat significantly decreased in KD (p = 0.030); whilst lean mass increased significantly only in WD (p < 0.001). Maximal strength increased similarly in both groups. KD showed a significant decrease of blood triglycerides (p < 0.001), glucose (p = 0.001), insulin (p < 0.001) and inflammatory cytokines compared to WD whilst BDNF increased in both groups with significant greater changes in KD (p < 0.001). Conclusions: KD may be used during body building preparation for health and leaning purposes but with the caution that hypertrophic muscle response could be blunted.

(-)-Gallocatechin gallate from green tea rescues cognitive impairment through restoring hippocampal silent synapses in post-menopausal depression

Post-menopausal depression (PMD) is a common psychological disorder accompanied by a cognitive deficit, which is caused by a series of uncontrolled emotional disruptions by strong environmental stressors during menopause. To overcome PMD-induced cognitive deficit, Green tea has been suggested as a dietary supplement because of its ameliorating effect on cognitive dysfunction induced by normal aging or neurodegenerative syndromes; however, its clinical use to improve PMD-accompanied cognitive deficit is still limited due to the controversy for the active ingredients and ambiguous mechanism of its action. Here, we developed modified high-temperature-processed green tea extract (HTP-GTE), which showed lower neuronal toxicity than the conventional green tea extract (GTE). We also demonstrated that HTP-GTE administration prevented the development of learned helplessness (LH) in a rat post-menopausal model. Additionally, HTP-GTE improved LH-induced cognitive impairments simultaneously with rescued the long-term synaptic plasticity. This occurred via the restoration of silent synapse formation by increasing the hippocampal BDNF-tyrosine receptor kinase B pathway in the helpless ovariectomized (OVX) rats. Likewise, we also identified that (-)-gallocatechin gallate was the main contributor of the HTP-GTE effect. Our findings suggested that HTP-GTE has a potential as a preventive nutritional supplement to ameliorate cognitive dysfunctions associated with PMD.

Depression, Estrogens, and Neuroinflammation: A Preclinical Review of Ketamine Treatment for Mood Disorders in Women

Ketamine has been shown to acutely and rapidly ameliorate depression symptoms and suicidality. Given that women suffer from major depression at twice the rate of men, it is important to understand how ketamine works in the female brain. This review explores three themes. First, it examines our current understanding of the etiology of depression in women. Second, it examines preclinical research on ketamine's antidepressant effects at a neurobiological level as well as how ovarian hormones present a unique challenge in interpreting these findings. Lastly, the neuroinflammatory hypothesis of depression is highlighted to help better understand how ovarian hormones might interact with ketamine in the female brain.

Is neurotrophin-3 (NT-3): a potential therapeutic target for depression and anxiety?

Introduction: Neurotrophin-3 (NT-3) is thought to play a role in the neurobiological processes implicated in mood and anxiety disorders. NT-3 is a potential pharmacological target for mood disorders because of its effects on monoamine neurotransmitters, regulation of synaptic plasticity and neurogenesis, brain-derived neurotrophic factor (BDNF) signaling boosting, and modulation of the hypothalamic-pituitary-adrenal (HPA) axis. The mechanisms underlying NT-3 anxiolytic properties are less clear and require further exploration and definition. Areas covered: The evidence that supports NT-3 as a pharmacological target for anxiety and mood disorders is presented and this is followed by a reflection on the quandaries, stumbling blocks, and future perspectives for this novel target. Expert opinion: There is evidence for miRNAs being key post-transcriptional regulators of neurotrophin-3 receptor gene (NTRK3) in anxiety disorders; however, the anxiolytic properties of NT-3 need further examination and delineation. Moreover, NT-3 expression by non-neuronal cells and its role in brain circuits that participate in anxiety and mood disorders require further scrutiny. Further work is vital before progression into clinical trials can be realized.

So-Ochim-Tang-Gamibang, a Traditional Herbal Formula, Ameliorates Depression by Regulating Hyperactive Glucocorticoid Signaling In Vitro and In Vivo

So-ochim-tang-gamibang (SOCG) is a Korean traditional medicine; it has previously been shown to be safe and effective against depression. Persistently increased levels of circulating glucocorticoids have been considered as a pathological mechanism for depression and associated with decreased neurotrophic factors in the hippocampus. This study investigated whether SOCG controls the hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis and the molecular mechanisms underlying its effects in vivo and in vitro. Wistar Kyoto (WKY) rats were subjected to restraint stress, where SOCG was orally administered to the animals for 2 weeks. An open field test (OFT), forced swimming test (FST), and sucrose preference test (SPT) were performed to explore the antidepressant activity of SOCG in WKY rats. Plasma levels of HPA axis hormones were measured by ELISA or western blotting analysis. The expression levels or activation of HPA axis-related signaling molecules such as brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), extracellular regulated kinase (ERK), and glucocorticoid receptors (GRs) in the brain were determined by real-time PCR and western blotting analysis. Furthermore, a corticosterone- (CORT-) induced cell injury model was established using SH-SY5Y cells to explore the antidepressive effects of SOCG in vitro. The results of the OFT, FST, and SPT revealed that SOCG ameliorated depressive-like behaviors in the WKY rats. The blood plasma levels of HPA axis hormones such as CORT, CORT-releasing hormone (CRH), and adrenocorticotrophic hormone were downregulated by SOCG. On the other hand, SOCG upregulated the phosphorylation of CREB and ERK in both the rat hippocampus and CORT-treated SH-SY5Y cells. Moreover, it also increased the GR expression. These results suggested that SOCG may improve depression by controlling hyperactive glucocorticoid signaling via the downregulation of HPA axis hormones and upregulation of GR.

CRTC1 signaling involvement in depression-like behavior of prenatally stressed offspring rat

A large body of literature has demonstrated that prenatal stress (PS) can induce depression-like behavior in the offspring. However, the underlying mechanism remains largely unknown. CREB-regulated transcriptional coactivator 1(CRTC1) has recently been shown to involve in mood regulation. This research aims to investigate whether CRTC1 signaling was involved in the depression-like behavior of prenatally stressed offspring rats. Sucrose preference test (SPT), forced swimming test (FST) and open field test (OFT) were adopted to test the depression-like behavior in the male offspring rats, and CRTC1 signaling was measured. The results showed that there were significantly reduced sucrose intake in SPT and prolonged immobility time in FST in PS-exposure offspring rats. It was also found decreased levels of total CRTC1, nuclear CRTC1, calcineurin, brain-derived neurotrophic factor (BDNF) and c-fos, but increased cytoplasmic p-CRTC1 in the hippocampus (HIP) and prefrontal cortex (PFC) of the offspring rats. Furthermore, the mRNA level of CRTC1, calcineurin, BDNF, c-fos were down-regulated. Abnormal expression of CRTC1 signaling could be alleviated by fluoxetine treatment. In conclusion, our research indicated that the aberration of CRTC1 expression and/or phosphorylation activity might play a vital role in PS-induced depression-like behavior of offspring rats.

Depression-like behaviors induced by defective PTPRT activity through dysregulated synaptic functions and neurogenesis

PTPRT has been known to regulate synaptic formation and dendritic arborization of hippocampal neurons. PTPRT-/- null and PTPRT-D401A mutant mice displayed enhanced depression-like behaviors compared with wild-type mice. Transient knockdown of PTPRT in the dentate gyrus enhanced the depression-like behaviors of wild-type mice, whereas rescued expression of PTPRT ameliorated the behaviors of PTPRT-null mice. Chronic stress exposure reduced expression of PTPRT in the hippocampus of mice. In PTPRT-deficient mice the expression of GluR2 (also known as GRIA2) was attenuated as a consequence of dysregulated tyrosine phosphorylation, and the long-term potentiation at perforant-dentate gyrus synapses was augmented. The inhibitory synaptic transmission of the dentate gyrus and hippocampal GABA concentration were reduced in PTPRT-deficient mice. In addition, the hippocampal expression of GABA transporter GAT3 (also known as SLC6A11) was decreased, and its tyrosine phosphorylation was increased in PTPRT-deficient mice. PTPRT-deficient mice displayed reduced numbers and neurite length of newborn granule cells in the dentate gyrus and had attenuated neurogenic ability of embryonic hippocampal neural stem cells. In conclusion, our findings show that the physiological roles of PTPRT in hippocampal neurogenesis, as well as synaptic functions, are involved in the pathogenesis of depressive disorder.