Cognitive dysfunction is a significant, untreated clinical need in patients with psychiatric disorders, for which preclinical studies are needed to understand the underlying mechanisms and to identify potential therapeutic targets. Early-life stress (ELS) leads to long-lasting deficits of hippocampus-dependent learning and memory in adult mice, which may be associated with the hypofunction of the brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin receptor kinase B (TrkB). In this study, we carried out eight experiments using male mice to examine the causal involvement of the BDNF-TrkB pathway in dentate gyrus (DG) and the therapeutic effects of the TrkB agonist (7,8-DHF) in ELS-induced cognitive deficits. Adopting the limited nesting and bedding material paradigm, we first demonstrated that ELS impaired spatial memory, suppressed BDNF expression and neurogenesis in the DG in adult mice. Downregulating BDNF expression (conditional BDNF knockdown) or inhibition of the TrkB receptor (using its antagonist ANA-12) in the DG mimicked the cognitive deficits of ELS. Acute upregulation of BDNF (exogenous human recombinant BDNF microinjection) levels or activation of TrkB receptor (using its agonist, 7,8-DHF) in the DG restored ELS-induced spatial memory loss. Finally, acute and subchronic systemic administration of 7,8-DHF successfully restored spatial memory loss in stressed mice. Subchronic 7,8-DHF treatment also reversed ELS-induced neurogenesis reduction. Our findings highlight BDNF-TrkB system as the molecular target of ELS-induced spatial memory deficits and provide translational evidence for the intervention at this system in the treatment of cognitive deficits in stress-related psychiatric disorders, such as major depressive disorder.

Background: The overall satisfaction of patients after total knee arthroplasty (TKA) is approximately 80%, and current studies have demonstrated that patients with depression may have lower patient satisfaction. The purpose of this study was to determine whether perioperative psychological intervention in patients with depression improves the clinical outcomes and patient satisfaction in patients undergoing TKA. Methods: Six hundred patients who underwent primary TKA from May 2016 to January 2018 were prospectively screened for eligibility. A preoperative psychological evaluation was conducted by a psychiatrist to evaluate each patient’s psychological status. Patients who were diagnosed with depression were randomly divided into 2 groups: the intervention group (patients received psychological interventions that were administered by a psychiatrist at the first visit before surgery and from then on) and the control group (patients received routine TKA care without psychological interventions). The primary outcome was patient satisfaction at 6 months postoperatively. The secondary outcomes were patient satisfaction at 2 years postoperatively as well as the Hospital for Special Surgery (HSS) scores, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and range of motion at 6 months and 2 years postoperatively. Results: Fifty-three patients with depression were identified. Fifty-one patients were enrolled in the randomized controlled trial. Two patients were lost to follow-up at 6 months after surgery. Therefore, 49 patients (25 in the intervention group and 24 in the control group) remained in the final analysis. At 6 months postoperatively, statistical differences in patient satisfaction were identified between the 2 groups (88.0% in the intervention group compared with 62.5% in the control group; odds ratio = 4.40; 95% confidence interval, 1.02 to 18.99). There was a significant improvement in the Self-Rating Depression Scale (SDS) score (the reduction rate was 51.97% in the intervention group compared with 17.35% in the control group) and the Symptom Checklist 90 Revised (SCL-90-R) subscore for depression (the reduction rate was 44.66% in the intervention group compared with 15.73% in the control group). The clinical outcomes, including the WOMAC scores, the HSS scores, and maximal range of motion, in the intervention group had improved significantly more compared with those in the control group. Conclusions: Psychological interventions during the perioperative period can improve patient satisfaction in patients with depression who undergo TKA. Therefore, psychological intervention and management may be beneficial for patients with depression who are planning to undergo TKA. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Background: Depression affects approximately 5% of elderly people and its etiology might be related to chronic stress exposure during neurodevelopmental periods. In this study, we examined the effects of adolescent chronic social stress in aged mice on depressive behaviors and the excitatory-inhibitory (E/I) balance in stress-sensitive regions of the brain. Methods: Sixty-four adolescent, male C57BL/6 mice were randomly assigned to either the 7-week (from post-natal days 29 to 77) social instability stress (stress group, n = 32) or normal housing conditions (control group, n = 32). At 15 months of age, 16 mice were randomly selected from each group for a series of behavioral tests, including two depression-related tasks (the sucrose preference test and the tail suspension test). Three days following the last behavioral test, eight mice were randomly selected from each group for immunohistochemical analyses to measure the cell density of parvalbumin (PV⁺)- and calretinin (CR⁺)-positive gamma-aminobutyric-acid (GABA)ergic inhibitory inter-neurons, and the expression levels of vesicular transporters of glutamate-1 (VGluT1) and vesicular GABA transporter (VGAT) in three stress-sensitive regions of the brain (the medial pre-frontal cortex [mPFC], hippocampus, and amygdala). Results: Behaviorally, compared with the control group, adolescent chronic stress increased depression-like behaviors as shown in decreased sucrose preference (54.96 ± 1.97% vs. 43.11 ± 2.85%, t₍₂₂₎ = 3.417, P = 0.003) and reduced latency to immobility in the tail suspension test (92.77 ± 25.08 s vs. 33.14 ± 5.95 s, t₍₂₅₎ = 2.394, P = 0.025), but did not affect anxiety-like behaviors and pre-pulse inhibition. At the neurobiologic level, adolescent stress down-regulated PV⁺, not CR⁺, inter-neuron density in the mPFC (F_{(1, 39)} = 19.30, P < 0.001), and hippocampus (F_{(1, 42)} = 5.823, P = 0.020) and altered the CR⁺, not PV⁺, inter-neuron density in the amygdala (F_{(1, 28)} = 23.16, P < 0.001). The VGluT1/VGAT ratio was decreased in all three regions (all F > 10.09, all P < 0.004), which suggests stress-induced hypoexcitability in these regions. Conclusions: Chronic stress during adolescence increased depression-like behaviors in aged mice, which may be associated with the E/I imbalance in stress-sensitive brain regions.

Chronic stress may disrupt the normal neurodevelopmental trajectory of the adolescent brain (especially the prefrontal cortex) and contribute to the pathophysiology of stress-related mental illnesses, but the underlying molecular mechanisms remain unclear. Here, we investigated how synaptic cell adhesion molecules (e.g., nectin3) are involved in the effects of adolescent chronic stress on mouse medial prefrontal cortex (mPFC). Male C57BL/6N mice were subjected to chronic social instability stress from postnatal days 29 to 77. One week later, the mice exposed to chronic stress exhibited impaired social recognition and spatial working memory, simplified dendritic structure, and reduced spine density in the mPFC. Membrane localization of nectin3 was also altered, and was significantly correlated with behavioral performance. Furthermore, knocking down mPFC nectin3 expression by adeno-associated virus in adolescent mice reproduced the stress-induced changes in behavior and mPFC morphology. These results support the hypothesis that nectin3 is a potential mediator of the effects of adolescent chronic stress on prefrontal structural and functional abnormalities.