Serum BDNF Levels Research Articles

Diabetes mellitus, cognitive deficits and serum BDNF levels in chronic patients with schizophrenia: A case-control study

The relationship between serum BDNF levels and cognitive dysfunction in schizophrenia (SCZ) patients comorbid with type 2 diabetes mellitus (T2DM) has not been reported. Hence, this study aimed to explore whether and how the changes of serum BDNF levels were correlated with cognitive impairment in SCZ patients comorbid with T2DM. We recruited 472 inpatients with chronic SCZ (54 T2DM and 418 non-T2DM), and 225 healthy controls. Serum BDNF levels and routine biochemical parameters were measured. Psychopathological symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS) and cognitive function was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). SCZ patients with T2DM had significantly higher serum BDNF levels than SCZ patients without T2DM (F = 11.31, p = 0.001). SCZ patients with T2DM scored higher in delayed memory than SCZ patients without T2DM (77.17 ± 18.44 vs.66.24 ± 19.51, p = 0.000), and still showed significance after controlling for confounders. Further stepwise multiple regression analysis identified serum BDNF as an independent contributor to the RBANS attention of SCZ patients with T2DM (β = 0.30, t = 2.09, p = 0.042). The increase of BDNF levels and better cognitive performance, especially delayed memory, may be related to the pathophysiological process of T2DM in chronic SCZ patients.

Incongruent Expression of Brain-Derived Neurotrophic Factor and Cortisol in Schizophrenia: Results from a Randomized Controlled Trial of Laughter Intervention.

ObjectiveSchizophrenia has been associated with dysfunction of the hypothalamic-pituitary-adrenal axis. Furthermore, alterations in neurotrophic factors might contribute to the pathogenesis of schizophrenia. We aimed to evaluate the effects of a simulated laughter intervention on the levels of cortisol and BDNF and to determine whether the effects associated with simulated laughter could be sustained after discontinuation of the intervention.MethodsIn this randomized controlled study, patients with schizophrenia according to DSM-IV clinical criteria were randomly assigned to receive either 8-week-long simulated laughter intervention (n=32) or treatment-as-usual group (control group, n=27). The serum levels of BDNF and cortisol were measured at baseline, week 8, and four weeks after discontinuation (week 12) of the intervention program. ResultsAfter an 8-week simulated laughter intervention, the laughter group had significantly higher levels of BDNF; however, four weeks after discontinuation of the intervention, the levels of BDNF significantly dropped. Interestingly, the levels of cortisol did not change significantly at week 8, but they were significantly elevated at week 12. The levels of BDNF and cortisol in the control group did not change significantly between week 0 and week 8. ConclusionThese findings suggest that the simulated laughter intervention has an early effect on neurogenesis with a significant delayed effect on stress regulation in subjects with schizophrenia.

Ratio of serum proBDNF to BDNF and its association with cognitive performance and brain morphometry in mild cognitive impairment

AbstractBackgroundBrain‐derived neurotrophic factor (BDNF) is the neurotrophin well‐known for its role in neurogenesis, synaptic plasticity and enhancement of long‐term potentiation (LTP). Its precursor proBDNF exhibits opposite biological function – inhibits LTP and increases long‐term depression (LTD) in the brain. Altered proBDNF/BDNF ratio in favor of the pro‐form may lead to enhancement of LTD and reduction of LTP in hippocampal neurons with consequent synaptic dysfunction and memory deficits. To explore this hypothesis, we investigated the associations of serum proBDNF, mature BDNF and its ratio (proBDNF/BDNF) with cognitive performance and structural changes of AD‐related brain regions in individuals with amnestic mild cognitive impairment (aMCI).Method95 individuals with aMCI (age = 68.5 ± 7.3; MMSE = 26.1 ± 2.4) were recruited from the Czech Brain Aging Study. All participants underwent clinical and laboratory evaluation (with APOE and BDNF genotyping), comprehensive neuropsychological examination and brain MRI (1.5T). FreeSurfer 5.3 software was used to measure left and right hippocampal volume and left and right entorhinal and parahippocampal thickness. Serum levels of proBDNF and BDNF were measured by sandwich enzyme‐linked immunosorbent assay (ELISA).ResultA negative correlation was found between serum proBDNF/BDNF ratio and verbal memory (r = ‐0. 25, p = 0.04) and executive function (r = ‐0. 30, p = 0.02) but not with other cognitive composite scores (ps > 0.26). A trend of positive correlation was found between serum BDNF levels and verbal memory domain (r = 0.23, p = 0.08). No other correlation between BDNF and proBDNF levels and cognitive performance was significant. Correlations of proBDNF and BDNF levels and its ratio with volume and thickness of AD‐related brain regions were not significant.ConclusionHigher proBDNF/BDNF ratio is associated with lower cognitive performance in verbal memory and executive function but not with structural brain changes in aMCI individuals. Our findings suggest that proBDNF/BDNF ratio may be a more reliable blood biomarker of cognitive change than BDNF and proBDNF levels alone.

Brain-derived neurotrophic factor is associated with coronary macrophage infiltrates in patients with acute coronary syndrome

Abstract Background Brain-derived neurotrophic factor (BDNF) is a neurotrophine that plays a key role in the regulation of both central and peripheral nervous system. Moreover, BDNF is secreted in multiple tissues and exerts systemic, autocrine, and paracrine effects in the cardiovascular system. Of importance, BDNF expression was enhanced in macrophages and smooth muscle cells in atherosclerotic coronary arteries and may be involved in thrombus formation. Thus, BDNF has been suggested as an important link between inflammation and thrombosis, potentially involved in the pathogenesis of acute coronary syndrome (ACS). Purpose In our study we aimed at assessing serum levels of BDNF in patients with ACS, evaluating differences according to clinical presentation [ST-segment elevation myocardial infarction (STEMI) vs. Non-ST-segment elevation ACS (NSTE-ACS)]. Moreover, we assessed the presence of optical coherence (OCT)-defined macrophage infiltrates (MØI) in the culprit vessel of ACS patients and evaluated their relationship with BDNF levels. Methods ACS patients were prospectively selected. Blood samples were collected at admission and serum levels of BDNF were subsequently assessed. Presence of OCT-defined MØI along the culprit vessel was assessed. Results 166 ACS patients were enrolled [mean age 65.3±11.9 years, 125 (75.3%) male, 109 STEMI, 57 NSTE-ACS]. Serum levels of BDNF were higher among STEMI patients compared with NSTE-ACS [median (IQR) 2.48 pg/mL (1.54–3.34) vs. 2.12 pg/mL (1.34–2.47), p=0.007], while C-reactive protein levels did not differ between the two groups. OCT assessment was performed in 53 patients and MØI were detected in 27 patients. Of importance, patients with MØI in the culprit vessel had higher levels of BDNF compared with patients without MØI [median (IQR) 2.23 pg/mL (1.38–2.53) vs. 1.41 pg/mL (0.93–2.07), p=0.023], while C-reactive protein levels did not differ between the two groups. Of note, at multivariate regression analysis BDNF levels were independent predictor of MØI [OR: 2.20; 95% CI (1.02–4.74), p=0.043]. Conclusions Serum levels of BDNF may reliable identify the presence of local macrophage inflammatory infiltrates in patients with ACS. Moreover, BDNF levels are higher in patients with STEMI compared with NSTE-ACS. Taken together, these data suggest that BDNF may represent an interesting link between local inflammatory activation and enhanced thrombosis in ACS. BDNF serum levels Funding Acknowledgement Type of funding source: None

P.745 Vortioxetine treatment elevates serum BDNF levels in MDD patients along with the improvement of cognitive and emotional characteristics

P.745 Vortioxetine treatment elevates serum BDNF levels in MDD patients along with the improvement of cognitive and emotional characteristics

The Effect of 12 Weeks of Pilates Training and Ginger Consumption on Serum Levels of BDNF and TNF-α in Women with Multiple Sclerosis

The Effect of 12 Weeks of Pilates Training and Ginger Consumption on Serum Levels of BDNF and TNF-α in Women with Multiple Sclerosis

Влияние курса нейромодуляции на профиль нейротрофических факторов у пациентов с хроническими нарушениями сознания

Transcranial magnetic stimulation (TMS) is one of rehabilitation approaches for patients with chronic disorders of consciousness (DOC). The aim of our study was to assess neurotrophic factors and the changes of those after TMS course in patients with chronic DOC. We enrolled 26 patients with chronic DOC of various etiology and 21 heathy volunteers. Blood serum and cerebrospinal fluid (CSF) were collected from all patients before and after the TMS course, the levels of BDNF, NSE, NGF, РDGF, GDNF and NT3 were assessed in the biomaterial. The blood BDNF, NSE, PDGF, GDNF and NT3 in patients with chronic DOC were higher compared to healthy volunteers (p < 0.05). We found no correlations between the type of DOC and neurotrophic factors concentrations in blood and CSF. The CSF level of BDNF in patients after traumatic brain injury (TBI) was higher compared to patients with non-traumatic chronic DOC (p < 0.05). We also found the increase of CSF BDNF after the TMS course in patients after TBI (p < 0.05). No other significant differences between groups and another blood and cerebrospinal fluid biomarker levels were detected. Thus, the serum BDNF, NSE, PDGF, GDNF and NT3 levels in patients with chronic DOC were higher compared to healthy volunteers. The BDNF level in CSF was higher in patients with traumatic DOC, and it also increased after the course of high-frequency TMS in this group. This fact may indicate the long-term neuronal plasticity processes in patients after TBI, as well as more favorable rehabilitation prognosis.

Contemplative mental training increases serum BDNF levels with differing success depending on practice type and training sequence

Contemplative mental training increases serum BDNF levels with differing success depending on practice type and training sequence

Indices of cortical plasticity after therapeutic sleep deprivation in patients with major depressive disorder

BackgroundTherapeutic sleep deprivation (SD) presents a unique paradigm to study the neurobiology of major depressive disorder (MDD). However, the rapid antidepressant mechanism, which differs from today's slow first-line treatments, is not sufficiently understood. We recently integrated two prominent hypotheses of MDD and sleep, the synaptic plasticity hypothesis of MDD and the synaptic homeostasis hypothesis of sleep-wake regulation, into a synaptic plasticity model of therapeutic SD in MDD. Here, we further tested this model positing that homeostatically elevating net synaptic strength through therapeutic SD shifts the initially deficient inducibility of associative synaptic long-term potentiation (LTP)-like plasticity in patients with MDD into a more favorable window of associative plasticity. MethodsWe used paired associative stimulation (PAS), a transcranial magnetic stimulation protocol (TMS), to quantify cortical LTP-like plasticity after one night of therapeutic sleep deprivation in 28 patients with MDD. ResultsWe demonstrate a significantly different inducibility of associative plasticity in clinical responders to therapeutic SD (> 50% improvement on the 6-item Hamilton-Rating-Scale for Depression, n=13) compared to non-responders (n=15), which was driven by a long-term depression (LTD)-like response in SD-non-responders. Indices of global net synaptic strength (wake EEG theta activity, intracortical inhibition and BDNF serum levels) were increased after SD in both groups, with responders showing a generally lower intracortical inhibition than non-responders. LimitationsRepetitive assessments prior to and after treatment would be needed to further determine potential mechanisms. ConclusionAfter a night of therapeutic SD, clinical responders show a significantly higher inducibility of associative LTP-like plasticity than non-responders.

The Diagnostic Value of the Combination of Serum Brain-Derived Neurotrophic Factor and Insulin-Like Growth Factor-1 for Major Depressive Disorder Diagnosis and Treatment Efficacy.

BackgroundLast decades of psychiatric investigations have been marked by a search for biological markers that can clarify etiology and pathogenesis, confirm the diagnosis, screen individuals at risk, define the severity, and predict the course of mental disorders. In our study, we aimed to evaluate if BDNF and IGF-1 serum concentrations separately and in combination might be used as biomarkers for major depressive disorder (MDD) diagnosis and treatment efficacy and to evaluate the relationships among those proteins and clinical parameters of MDD.MethodsForty-one MDD patients (according to DSM-5) and 32 healthy controls (HC) were included in this study. BDNF and IGF-1 serum concentrations, psychopathological (MADRS, CGI) and neuropsychological parameters (PDQ-5, RAVLT, TMT-B, DSST), functioning according to Sheehan Disability Scale were analyzed in all subjects at admission and 30 MDD patients after 8 weeks of vortioxetine treatment. Correlational analyses were performed to explore relationships between BDNF and IGF-1 and clinical characteristics. AUC-ROCs were calculated to determine if the value of serum BDNF and IGF-1 levels could serve for MDD diagnosis.ResultsMDD patients had significantly lower serum BDNF (727.6 ± 87.9 pg/ml vs. 853.0 ± 93.9 pg/ml) and higher serum IGF-1 levels (289.15 ± 125.3 ng/ml vs. 170.2 ± 58.2 ng/ml) compared to HC. Significant correlations were obtained between BDNF levels and MDD status, depressive episode (DE) severity, precipitating factors, executive functions disruption (TMT-B, RAVLT immediate recall scores) and all subdomains of functioning. As for IGF-1, correlations were found between IGF-1 level and MDD status, DE severity, number and duration of DE, parameters of subjective and objective cognitive functioning (PDQ-5, RAVLT, TMT-B, DSST scores), and all subdomains of functioning. The associations between IGF-1 concentrations and cognitive tests’ performance were stronger than those of BDNF. Separately both BDNF and IGF-1 demonstrated good discriminating ability for MDD diagnosis with AUC of 0.840 and 0.824, respectively. However, the combination of those neurotrophins had excellent diagnostic power to discriminate MDD patients from HC, providing an AUC of 0.916. Vortioxetine treatment significantly increased BDNF and attenuated IGF-1 serum concentrations, improved all psychopathological and neuropsychological parameters and functioning.ConclusionsThe combination of IGF-1 and BDNF might be considered as a diagnostic combination for MDD.

Brain-derived neurotrophic factor in bipolar disorder: Associations with age at onset and illness duration

Bipolar disorder (BD) is a heterogeneous disorder that contains neurodevelopmental differences. Defining homogeneous subgroups of BD patients by using age at onset (AAO) as a specifier may promote the classification of biomarkers. This study compares peripheral BDNF levels between pediatric and adult BD patients to investigate the associations between BDNF levels, AAO, and illness duration. We enrolled two groups of euthymic patients, those with pediatric BD (n = 39) and those with adult BD (n = 31), as well as a group of healthy controls (HCs) (n = 90). Participants were assessed using clinical measures and BDNF serum levels were obtained using ELISA. We observed that BDNF levels were comparable between adult BD and HCs, but were clearly lower in pediatric BD than in HCs. In adult BD with AAO ≥30 years, BDNF levels were significantly higher than in adult BD with AAO <30 years. In pediatric BD, patients with prepubertal-onset had higher BDNF levels than those with pubertal-onset. BDNF levels demonstrated the accuracy of being able to distinguish pediatric BD from healthy controls in a receiver operating characteristic (ROC) curve analysis (area under the curve [AUC] = 0.792). In adult BD, higher BDNF levels were associated with later disease onset, but this was not the case in pediatric BD. Finally, reduced BDNF levels were associated with illness duration in adult BD. The findings indicate that BDNF levels in BD patients are associated with AAO. BDNF may, therefore, potentially serve as a developmental marker in BD, when AAO is taken into account.

The Antidiabetic Metformin as an Adjunct to Antidepressants in Patients with Major Depressive Disorder: A Proof-of-Concept, Randomized, Double-Blind, Placebo-Controlled Trial.

Metformin (MET) has been reported to have antidepressant effects in animal models and in diabetic patients with depression, owing to its anti-inflammatory, antioxidant, and neuroprotective activity. Accordingly, we proposed that MET would show antidepressant effects in patients with major depressive disorder (MDD) without other comorbidities. In this double-blind placebo-controlled study, 80 adult outpatients with MDD (DSM-IV criteria) and a Hamilton Depression Rating Scale (HAM-D) score >18 were randomized to receive fluoxetine 20 mg once daily plus placebo (n = 40) or fluoxetine 20 mg once daily plus MET 1000 mg once daily for 12 weeks. Patients were assessed by HAM-D score (weeks 0, 4, 8, and 12). The serum levels of TNF-α, IL-1β, IL-6, IGF-1, MDA, CRP, BDNF, and serotonin were measured before and after therapy. Mixed-effects model repeated-measures analysis of covariance was used to compare the HAM-D scores and the biological markers between the two groups. After 4, 8 and 12 weeks, patients in the MET group showed a statistically significant decline in HAM-D score relative to the placebo group (least squares mean difference [LSMD] -2.347, p = 0.000, LSMD -3.369, p = 0.000, and LSMD -3.454, p = 0.000, respectively). Response and remission rates were significantly higher in the MET group (89% and 81%, respectively) than in the placebo group (59% and 46%, respectively). Moreover, the MET group was superior in conserving the measured biological markers compared with the placebo group. Our findings suggest MET as a promising, effective, and safe short-term adjunctive approach in nondiabetic MDD patients. Trial registration ID: NCT04088448.

Serum BDNF Levels are Not Associated with the Antidepressant Effects of Nonconvulsive Electrotherapy.

ObjectiveBrain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of depression and in the antidepressant response. This study examined whether changes in serum BDNF levels are associated with the antidepressant effects of nonconvulsive electrotherapy (NET).MethodsFor BDNF analyses, serum samples were collected from 20 patients with treatment-refractory depression (TRD) and from 20 healthy controls. Serum samples were also collected from patients following a course of NET.ResultsAlthough significantly lower baseline serum BDNF levels were observed in TRD patients than in healthy controls, no changes in serum BDNF levels were found in TRD patients after a course of NET compared to baseline. No significant association was found between serum BDNF levels and depression severity.ConclusionSerum BDNF levels appear to have no clinical utility in the prediction of the antidepressant effects of NET in patients with TRD. Future studies of higher quality and with larger sample sizes are needed to confirm these findings.

Brain-derived neurotrophic factor among patients with alcoholism.

Brain-derived neurotrophic factor (BDNF) is involved in neurogenesis and in the protection against oxidative damage and neuronal apoptosis. After exercise, there is an increased expression of this myokine, especially in skeletal muscle and brain. Low BDNF levels have been described in neurodegenerative diseases. Alcoholics show both muscle atrophy and brain atrophy. Thus, this study was performed in order to analyze serum BDNF levels among alcoholics and their associations with brain atrophy and muscle strength. Serum BDNF values were determined to 82 male alcoholics and 27 age-matched controls, and compared with handgrip strength, with the presence of brain atrophy, assessed by computed tomography, and with the intensity of alcoholism and liver function derangement. BDNF levels and handgrip strength were significantly lower among patients. Handgrip strength was correlated with BDNF values, both in the whole population and in alcoholics, especially in patients over 59 years of age. BDNF was poorly related to liver dysfunction but showed no relationship with brain atrophy or age. Chronic alcoholics show decreased BDNF serum levels that are related to muscle function impairment rather than to age, brain atrophy, liver dysfunction, or the amount of ethanol consumed.

The Effect of 8 Weeks of HICT Training on Serum Levels of BDNF and TNFa and Aerobic Power in Breast Cancer Survivors: Randomized Clinical Trial

The Effect of 8 Weeks of HICT Training on Serum Levels of BDNF and TNFα and Aerobic Power in Breast Cancer Survivors: Randomized Clinical Trial

Use of Various Doses of S-Ketamine in Treatment of Depression and Pain in Cervical Carcinoma Patients with Mild/Moderate Depression After Laparoscopic Total Hysterectomy.

BackgroundThis study investigated the effects of various doses of S-ketamine on depression and pain management of cervical carcinoma patients with mild/moderate depression.Material/MethodsThis randomized, double-blind, controlled study included 417 cervical carcinoma patients who received laparoscopic modified radical hysterectomy from April 2015 to July 2018 and who also had mild/moderate depression symptoms based on HAMD-17 scores (8~24). All patients were randomized into 4 groups: 1) the control group, 2) the racemic ketamine group, 3) the high-dose S-ketamine group; and 4) the low-dose S-ketamine group. Pain was assessed using the Visual Analogue Score (VAS), and depression was assessed using theHAMD-17 score. Serum levels of BDNF and 5-HT were measured.ResultsThe 4 groups of patients showed no significant differences in operation time, bleeding volume, hospitalization duration, or complications. The high-dose S-ketamine group showed significantly lower VAS and HAMD-17 scores than all other groups at 1 day and 3 days postoperatively, but no differences were observed in the low-dose S-ketamine group and the racemic ketamine group. The high-dose S-ketamine group showed significantly higher serum BDNF and 5-HT levels at 1 day and 3 days after surgery. However, 1 week after surgery, no difference was observed in any of the treatment groups.ConclusionsAt subanesthetic dose, both 0.5 mg/kg and 0.25 mg/kg S-ketamine improved short-term depression and pain for cervical carcinoma patients after surgery, and the effects were better than with the same dose of racemic ketamine.

Diagnostic Value of Serum Biomarkers for Differentiating Central and Peripheral Causes of Acute Vertigo.

Background: In patients presenting with acute vertigo or dizziness, distinguishing central from peripheral is a diagnostic challenge. This study investigated potential serum markers for differentiating central and peripheral vertigo in patients with acute-onset vertigo.Methods: This prospective case–control study recruited consecutive participants from the Emergency Department, including patients with acute-onset vertigo or dizziness within 12 h and control subjects. We used enzyme-linked immunosorbent assays to measure the serum S100β, NSE, BDNF, GFAP, and IL-6 levels during the acute period.Results: The 114 study subjects included 28 patients with central vertigo (CV), 49 patients with peripheral vertigo (PV), and 37 age- and sex-matched healthy controls. No differences were found in risk factor distribution among the three groups. In patients with CV, the serum NSE and S100β levels were significantly (p < 0.05) elevated compared with the control and PV groups. The ROC analysis gave an AUC of 0.843 (95% CI = 0.753–0.932) for NSE and 0.787 (95% CI = 0.687–0.886) for S100β for predicting CV. However, there were no significant differences in the serum GFAP and BDNF levels among the CV, PV, and control groups.Conclusions: Serum NSE and S100β levels are significantly higher in patients with CV, such as occurs with posterior circulation ischemic stroke or vertebrobasilar insufficiency. S100β and NSE may serve as serum biomarkers for differentiating between CV and PV in patients with acute-onset vertigo.

Relationship between serum brain-derived neurotrophic factor and clinical stage and dysmenorrhoea of enodmetriosis

Objective: To explore the association between serum brain-derived neurotrophic factor and clinical stage and dysmenorrhoea of endometriosis. Methods: A total of 82 patients were studied with laparoscopically diagnosed endometriosis between June 2017 and June 2019, and 75 healthy women with reproductive age were selected as the control group during the same period. The endometriosis patients were scored by visual analogue scale(VAS)according to their preoperative dysmenorrhoea.And endometriosis was staged and scored according to the score of Revised American Fertility Society(r-AFS).Enzyme-linked immunosorbent assay (ELISA) was used to determine preoperative BDNF level in serum, and the correlation between BDNF level with clinical stage as well as dysmenorrhea of endometriosis were analysed. Results: The serum BDNF level in endometriosis patients was (1 082±43) ng/L, significantly higher than that in the normal control [(649±30) ng/L], there was statistical difference between the two groups(P<0.001). The BDNF expression in patients with r-AFS stage Ⅲ-Ⅳ was higher than that in patients with Ⅰ-Ⅱ stage [(1 164±389) ng/L vs (791±218)ng/L, P<0.001]. BDNF level in serum was closely correlated with the degree of dysmenorrhea (r=0.682), and the BDNF level in patients with moderate or severe dysmenorrhea was significantly higher than that in patients without dysmenorrhea and patients with mild dysmenorrhea [(1 292±43) ng/L vs(718±36) ng/L, P<0.001]. Conclusions: The serum BDNF level in endometriosis patients is positively correlated with clinical stage and dysmenorrhea.

Effect of crocin on morphine tolerance and serum BDNF levels in a rat model of neuropathic pain.

Chronic use of morphine treatment for neuropathic pain leads to morphine-induced analgesic tolerance. Crocin contained in Crocus sativus L., exerts anti-inflammatory and analgesic effects. This study examined the effects of crocin on morphine tolerance and serum BDNF levels on neuropathic pain induced by chronic constriction injury (CCI) in rats. CCI model of neuropathic pain was done in male Wistar rats (200-250g). Rats were treated with crocin (15 or 30mg/kg, intraperitoneally) alone or simultaneously with morphine (10mg/kg, subcutaneously) during or after induction of CCI. Pain behavioral responses including mechanical allodynia and thermal hyperalgesia were measured from days of 15-27 after CCI. Then, rats were evaluated for serum BDNF levels on days 14 and/or 27. We found that morphine tolerance developed after the induction of neuropathic pain. The injection of crocin (15 and 30mg/kg) was able to enhance analgesic effect of morphine by reduction of mechanical allodynia on days 15-27 post-surgery in CCI rats. While preemptive administration of crocin at a lower dose (15mg/kg) maintained the analgesic effect of morphine. Morphine injection and/or co-administration with crocin (15, 30mg/kg) decreased serum BDNF levels in CCI rats. These findings indicate that crocin may have a therapeutic effect to maintain morphine analgesic efficacy and also to prevent the development of morphine tolerance in neuropathic pain, but probably not through BDNF.

Interaction between job stress, serum BDNF level and the BDNF rs2049046 polymorphism in job burnout

BackgroundSome studies have shown that long-term exposure to job stress could result in burnout, and BDNF polymorphism may play an important role in its psychopathological mechanism. However, the inter-relationships between the job-related stress, serum BDNF level, BDNF genotype and job burnout have not been examined. This study was to explore the job stress × BDNF rs2049046 interaction and the role of serum BDNF level in job burnout in a Chinese Han population. MethodsUsing a cross-sectional design, 205 healthy subjects were recruited from a public institution in Beijing and assessed for job stress using the House and Rizzo's Work Stress Scale, and job burnout using the Maslach Burnout Inventory (MBI). The BDNF rs2049046 polymorphism was genotyped and serum BDNF (sBDNF) levels were assayed in all of subjects. ResultsThe correlations between the job stress score and two burnout subscale scores (emotional exhaustion and cynicism) were significant (both p < 0.001), but not with professional efficacy. There were no significant main effects of the BDNF rs2049046 genotype on burnout, and no significant correlation was observed between sBDNF levels and job burnout. However, the interaction between the job stress and the BDNF rs2049046 genotype (F = 2.709, df = 2, 183, p = 0.032) or between the job stress and sBDNF levels on burnout was significant (t = −2.132, p = 0.035). To be specific, the individuals with the BDNF rs2049046 AT genotype showed a greater susceptibility to the burnout cynicism compared to AA homozygote only in medium-stress group (F = 4.327, df = 1,117, p = 0.015). The individuals who had lower sBDNF showed higher burnout level than those who had higher sBDNF in low-stress group. ConclusionsOur findings suggest that the BDNF system may interact with job stress to affect burnout, showing that interaction between BDNF rs2049046 and job stress or the interaction between BDNF levels with work stress on certain burnout dimensions.