Mental arithmetic has been verified inducing cerebral and cardiovascular responses. However, the mechanism and sequential responses are still ambiguous. This study aims to reveal the mechanism of cardiovascular and autonomic responses and the related scalp positions that regulate the autonomic nerves system (ANS) during MA task. 34 healthy male subjects aged between 19 and 27 years old (mean age 23.6 ± 2.3 years) were recruited in. Electrocardiogram, impedance cardiography, beat-to-beat blood pressure and electroencephalography were measured simultaneously and continuously during the experiments. And the analysis of time–frequency, approximate entropy and Pearson correlation coefficient were adopted. For statistical comparison, paired t test is utilized in the study. The results showed that mental arithmetic task increased heart rate (from 72.35 ± 1.88 to 80.38 ± 2.34), blood pressure (systolic blood pressure: from 112.09 ± 3.23 to 126.79 ± 3.44; diastolic blood pressure: from 74.15 ± 1.93 to 81.20 ± 1.97), and cardiac output (from 8.71 ± 0.30 to 9.68 ± 0.35), and the mental arithmetic induced physiological responses could be divided into two stages, the first stage (10–110 s) and late stage (150–250 s). The high frequency power component (HF) of HRV decreased during MA, but the normalized low frequency power component (nLF) and LF/HF ratio of HRV increased only at the late stage. Moreover, during first stage, the correlations between approximate entropy of electroencephalography at Fp2, Fz, F4, F7 and the corresponding time–frequency results of HF were significant. During the late stage, the correlations between approximate entropy of electroencephalography at Fp2, Fz, C3, C4 and the corresponding nLF was significant. Our results demonstrated that (1) mental stress induces time-dependent ANS activity and cardiovascular response. (2) Parasympathetic activity is lower during mental arithmetic task, but sympathetic nerve is activated only during late stage of mental arithmetic task. (3) Brain influences the cardiac activity through prefrontal and temporal cortex with the activation of ANS during mental arithmetic.

During bone remodeling, high extracellular calcium levels accumulated around the resorbing bone tissue as soon as the activation of osteoclasts. However, if and how calcium is involved in the regulation of bone remodeling remains unclear. In this study, the effect of high extracellular calcium concentrations on osteoblast proliferation and differentiation, intracellular calcium ([Ca²⁺]_i) levels, metabolomics, and the expression of proteins related to energy metabolism were investigated. Our results showed that high extracellular calcium levels initiated a [Ca²⁺]_i transient via the calcium-sensing receptor (CaSR) and promoted the proliferation of MC3T3-E1 cells. Metabolomics analysis showed that the proliferation of MC3T3-E1 cells was dependent on aerobic glycolysis, but not the tricarboxylic acid cycle. Moreover, the proliferation and glycolysis of MC3T3-E1 cells were suppressed following the inhibition of AKT. These results indicate that calcium transient triggered by high extracellular calcium levels activated glycolysis via AKT-related signaling pathways and ultimately promoted the proliferation of osteoblasts.

Aims: As the ovaries age and women transition to menopause and postmenopause, reduced estradiol levels are associated with anxiety and depression. Exercise contributes to alleviate anxiety and depression and the bone‐derived hormone osteocalcin has been reported to be necessary to prevent anxiety‐like behaviors. The aim of this study was to investigate the effects of exercise on anxiety behaviors in climacteric mice and whether it was related to osteocalcin.Methods: Menopausal mouse model was induced by intraperitoneal injection of 4‐vinylcyclohexene diepoxide (VCD). Open field, elevated plus maze, and light–dark tests were used to detect anxious behavior in mice. The content of serum osteocalcin was measured and its correlation with anxiety behavior was analyzed. BRDU and NEUN co‐localization cells were detected with immunofluorescence. Western blot was applied to obtain apoptosis‐related proteins.Results: The VCD mice showed obvious anxiety‐like behaviors and 10 weeks of treadmill exercise significantly ameliorated the anxiety and increased circulating osteocalcin in VCD mice. Exercise increased the number of BRDU and NEUN co‐localization cells in hippocampal dentate gyrus, reduced the number of impaired hippocampal neurons, inhibited the expression of BAX, cleaved Caspase3, and cleaved PARP, promoted the expression of BCL‐2. Importantly, circulating osteocalcin levels were positively associated with the improvements of anxiety, the number of BRDU and NEUN co‐localization cells in hippocampal dentate gyrus and negatively related to impaired hippocampal neurons.Conclusion: Exercise ameliorates anxiety behavior, promotes hippocampal dentate gyrus neurogenesis, and inhibits hippocampal cell apoptosis in VCD‐induced menopausal mice. They are related to circulating osteocalcin, which are increased by exercise.

The health risks associated with acute noise exposure are increasing, particularly the risk of mental health. This study aims to identify the association between acute high-intensity noise exposure and anxiety behavior in male rats, and to explore the associated neurobiological mechanisms. Male rats were subjected to different levels of acute high-intensity noise to determine the intensity that causes long-lasting anxiety-like behaviors. Anxiety-like behaviors were evaluated using the open field test (OFT) and the elevated plus maze test (EPMT) on the third day and 1month post-exposure, respectively. A range of techniques, including immunofluorescence staining, western blot, ELISA, and real-time quantitative PCR, were used to investigate neuronal apoptosis, glial cell activation, neuroinflammation, and blood-brain barrier (BBB) disruption in the hippocampus. Upon exposure to 135 dB of acute noise, male rats exhibited enduring anxiety-like behaviors. Subsequent investigations discovered that this noise intensity not only activated glial cells and triggered neuroinflammation within the hippocampus but also decreased the expression levels of ZO-1, claudin-5, and occludin, suggesting a disruption of the BBB. Additionally, this exposure was associated with the induction of neuronal apoptosis in the hippocampal region. In conclusion, acute exposure to 135 dB noise may cause persistent anxiety in male rats through a cyclical interaction between neuroinflammation and BBB disruption, potentially leading to neuronal apoptosis.